Background The purpose of this prospective study was to assess the injury rates in male and female adult Canadian Taekwondo athletes relative to total number of injuries, type and body part injured.
Background
The purpose of this prospective study was to assess the injury rates in male and female adult Canadian Taekwondo athletes relative to total number of injuries, type and body part injured.Methods Subjects (219 males, 99 females) participated in the 1997 Canadian National Taekwondo Championships in Toronto, Canada. Injuries were recorded on an injury form to documents any injury seen and treatment provided by the health care team. These data were later used for this study. The injury form describes the athlete and nature, site, severity and mechanism of the injury.
Methods
Subjects (219 males, 99 females) participated in the 1997 Canadian National Taekwondo Championships in Toronto, Canada. Injuries were recorded on an injury form to documents any injury seen and treatment provided by the health care team. These data were later used for this study. The injury form describes the athlete and nature, site, severity and mechanism of the injury.Results The overall rate of injuries was 62.9/1,000 athlete-exposures (A-E). The males (79.9/1,000 A-E) sustained significantly more injuries than the females (25.3/1,000 A-E). The lower extremities were the most commonly injured body region in the men (32.0 /1,000 A-E), followed by the head and neck (18.3/1,000 A-E). Injuries to the spine (neck, upper back, low back and coccyx) were the third most often injured body region in males (13.8/1,000 A-E). All injuries to the women were sustained to the lower extremities. The most common type of injury in women was the contusion (15.2/1,000 A-E). However, men's most common type of injury was the sprain (22.8/1,000 A-E) followed by joint dysfunction (13.7/1,000A-E). Concussions were only reported in males (6.9/1,000 A-E). Compared to international counterparts, the Canadian men and women recorded lower total injury rates. However, the males incurred more cerebral concussions than their American colleagues (4.7/1,000 A-E).
Results
The overall rate of injuries was 62.9/1,000 athlete-exposures (A-E). The males (79.9/1,000 A-E) sustained significantly more injuries than the females (25.3/1,000 A-E). The lower extremities were the most commonly injured body region in the men (32.0 /1,000 A-E), followed by the head and neck (18.3/1,000 A-E). Injuries to the spine (neck, upper back, low back and coccyx) were the third most often injured body region in males (13.8/1,000 A-E). All injuries to the women were sustained to the lower extremities. The most common type of injury in women was the contusion (15.2/1,000 A-E). However, men's most common type of injury was the sprain (22.8/1,000 A-E) followed by joint dysfunction (13.7/1,000A-E). Concussions were only reported in males (6.9/1,000 A-E). Compared to international counterparts, the Canadian men and women recorded lower total injury rates. However, the males incurred more cerebral concussions than their American colleagues (4.7/1,000 A-E).Conclusions Similar to what was found in previous studies, the current investigation seems to suggest that areas of particular concern for preventive measures involve the head and neck as well as the lower extremities. This is the first paper to identify spinal joint dysfunction.
Conclusions
Similar to what was found in previous studies, the current investigation seems to suggest that areas of particular concern for preventive measures involve the head and neck as well as the lower extremities. This is the first paper to identify spinal joint dysfunction.

Background With the inclusion of Taekwondo as a medal sport in the 2000 Olympic Games interest has gained momentum from participants, national governments and scientists alike. With increased participation, the issue of safety becomes very important and timely. The rules and regulations with regards to these Championships were that of the World Taekwondo Federation [ 1 ]. All athletes were sixteen years of age and older and held black belt first degree as a minimum requirement to compete. At the time of data collection, punches were allowed to the front of the torso in the area covered by the chest protector worn by the athletes. No punches were allowed to the head or other parts of the body. Kicks were allowed to the torso and head, the latter of which was covered by a helmet similar to the one worn in amateur boxing. Regardless of the area of contact, only one point was granted by the referees for a successful blow. One could win the match by means of a knockout, therefore, contact was encouraged. There was a change of rules introduced in 2003, which included granting two points for head shots and an additional point for an eight-count knockout [ 1 ]. Prospective studies on Taekwondo injuries sustained at single tournaments have been conducted before [ 1 - 3 ]. For instance, Zemper and Pieter [ 2 ] found injury rates for American elite male Taekwondo athletes to be 127.4/1,000 athlete-exposures and for females, 90.1/1,000 athlete-exposures. One athlete-exposure (A-E) refers to one athlete being exposed to the possibility of being injured. Since there are always two athletes competing during any one bout, there are two athlete-exposures per bout [ 2 , 3 ]. In a later study, Pieter et al. [ 3 ] reported injury rates of 139.5/1,000 A-E and 96.5/1,000 A-E for European men and women, respectively. In neither study were the differences tested for statistical significance. However, at a recreational tournament in the United Kingdom, the men (51.3/1,000 A-E) sustained statistically significantly more injuries than the women (47.6/1,000 A-E) [ 4 ]. It is not clear why the men in the studies mentioned above sustained more injuries. Sample size may be a factor. For instance, in a prospective study covering multiple Taekwondo tournaments, Pieter and Zemper [ 5 ] reported a statistically significantly higher injury rate for the women (105.5/1,000 A-E versus 95.1/1,000). In the largest prospective judo injury study to date, young and adult females (130.6/1,000 A-E) incurred a higher injury rate than their male counterparts (122.6/1,000 A-E) [ 6 ]. In addition to sample size, the number of female competitors is also lower [ 5 , 6 ]. As expected in a collision sport, the contusion was the most frequently occurring injury type in both male and female Taekwondo athletes [ 2 - 4 ]. At the elite level, more serious injuries such as fractures and cerebral concussions also occur [ 3 , 7 ]. Men seem to incur more of these serious injuries [ 2 , 3 ]. Less information is available in karate, for the authors have not consistently reported the injuries by gender. Based on what is known from prospective studies on elite karate athletes, the men also seem to incur more serious injuries, some of which have led to time loss [ 8 , 9 ]. The body region most frequently affected in single tournaments involving both recreational and elite Taekwondo athletes is the lower extremities, especially the (instep of the) foot [ 2 - 4 ]. Since full-contact or Olympic Taekwondo is characterized by kicking, this should come as no surprise. There is a lack of data on gender differences in injuries to body region and body part in karate. Most prospective studies combined the injury rates for males and females [e.g., [ 8 ]]. Using a prospective design, Pieter [ 10 ] reported that the head and neck sustained most of the injuries in both elite male and female karate athletes. There is also scarce information on male-female comparisons on body regions injured in judo athletes. Our own studies in judo seem to indicate that in the women, the upper extremities are mostly affected, while in the men, the head and neck as well as the lower extremities are injured most often [ 11 , 12 ]. In line with the frequent use of the legs in Taekwondo, the main injury mechanism was found to be delivering or receiving a kick [ 2 , 5 ]. Further analysis revealed that the roundhouse kick was most often implicated, especially in men [ 3 , 4 , 13 ]. The fact that injuries occur as a result of receiving a kick may be partially related to unblocked attacks, which has led to the recommendation for the coaches to work on improving the blocking skills or evasive maneuvers of their athletes [ 2 ]. The purpose of this study was to identify and compare the rates of injury in Canadian male and female Taekwondo competitors relative to total number of injuries, type, body part injured and mechanism.
Background
With the inclusion of Taekwondo as a medal sport in the 2000 Olympic Games interest has gained momentum from participants, national governments and scientists alike. With increased participation, the issue of safety becomes very important and timely. The rules and regulations with regards to these Championships were that of the World Taekwondo Federation [ 1 ]. All athletes were sixteen years of age and older and held black belt first degree as a minimum requirement to compete. At the time of data collection, punches were allowed to the front of the torso in the area covered by the chest protector worn by the athletes. No punches were allowed to the head or other parts of the body. Kicks were allowed to the torso and head, the latter of which was covered by a helmet similar to the one worn in amateur boxing. Regardless of the area of contact, only one point was granted by the referees for a successful blow. One could win the match by means of a knockout, therefore, contact was encouraged. There was a change of rules introduced in 2003, which included granting two points for head shots and an additional point for an eight-count knockout [ 1 ].Prospective studies on Taekwondo injuries sustained at single tournaments have been conducted before [ 1 - 3 ]. For instance, Zemper and Pieter [ 2 ] found injury rates for American elite male Taekwondo athletes to be 127.4/1,000 athlete-exposures and for females, 90.1/1,000 athlete-exposures. One athlete-exposure (A-E) refers to one athlete being exposed to the possibility of being injured. Since there are always two athletes competing during any one bout, there are two athlete-exposures per bout [ 2 , 3 ]. In a later study, Pieter et al. [ 3 ] reported injury rates of 139.5/1,000 A-E and 96.5/1,000 A-E for European men and women, respectively. In neither study were the differences tested for statistical significance. However, at a recreational tournament in the United Kingdom, the men (51.3/1,000 A-E) sustained statistically significantly more injuries than the women (47.6/1,000 A-E) [ 4 ].It is not clear why the men in the studies mentioned above sustained more injuries. Sample size may be a factor. For instance, in a prospective study covering multiple Taekwondo tournaments, Pieter and Zemper [ 5 ] reported a statistically significantly higher injury rate for the women (105.5/1,000 A-E versus 95.1/1,000). In the largest prospective judo injury study to date, young and adult females (130.6/1,000 A-E) incurred a higher injury rate than their male counterparts (122.6/1,000 A-E) [ 6 ]. In addition to sample size, the number of female competitors is also lower [ 5 , 6 ].As expected in a collision sport, the contusion was the most frequently occurring injury type in both male and female Taekwondo athletes [ 2 - 4 ]. At the elite level, more serious injuries such as fractures and cerebral concussions also occur [ 3 , 7 ]. Men seem to incur more of these serious injuries [ 2 , 3 ]. Less information is available in karate, for the authors have not consistently reported the injuries by gender. Based on what is known from prospective studies on elite karate athletes, the men also seem to incur more serious injuries, some of which have led to time loss [ 8 , 9 ].The body region most frequently affected in single tournaments involving both recreational and elite Taekwondo athletes is the lower extremities, especially the (instep of the) foot [ 2 - 4 ]. Since full-contact or Olympic Taekwondo is characterized by kicking, this should come as no surprise.There is a lack of data on gender differences in injuries to body region and body part in karate. Most prospective studies combined the injury rates for males and females [e.g., [ 8 ]]. Using a prospective design, Pieter [ 10 ] reported that the head and neck sustained most of the injuries in both elite male and female karate athletes.There is also scarce information on male-female comparisons on body regions injured in judo athletes. Our own studies in judo seem to indicate that in the women, the upper extremities are mostly affected, while in the men, the head and neck as well as the lower extremities are injured most often [ 11 , 12 ].In line with the frequent use of the legs in Taekwondo, the main injury mechanism was found to be delivering or receiving a kick [ 2 , 5 ]. Further analysis revealed that the roundhouse kick was most often implicated, especially in men [ 3 , 4 , 13 ]. The fact that injuries occur as a result of receiving a kick may be partially related to unblocked attacks, which has led to the recommendation for the coaches to work on improving the blocking skills or evasive maneuvers of their athletes [ 2 ].The purpose of this study was to identify and compare the rates of injury in Canadian male and female Taekwondo competitors relative to total number of injuries, type, body part injured and mechanism.Methods Subjects (219 males and 99 females) participated in the 1997 Canadian National Taekwondo Championships in Toronto, Canada. Injuries were recorded on an injury form to document any injury seen and treatment provided by the health care team as it was required by law. The first author was the only person who kept the injury forms and entered the data, therefore, keeping the identity of athletes confidential. Oral consent was obtained from the athletes for assessment and providing therapy. Data describe the athlete and nature, site, severity and mechanism of the injury. No reliability and validity information for the instrument is available and this study was carried out to pre-test the injury data collection form (Figure  1 ). Injuries were diagnosed by the tournament physician (MK), who has been the national team chiropractic physician for several years and is an experienced (black belt) Taekwondo athlete himself. One injury form was filled out by the attending physician for each time the athlete reported a new injury. However, at each presentation there could be more than one injury reported on the same Injury Report form. For the purposes of this study, an athlete was considered injured if any of the following conditions applied [ 14 ]: 1) any circumstance that forced the Taekwondo athlete to leave the competition; 2) any circumstance for which the referee or athlete had to stop competition; 3) any circumstance for which the athlete requested medical attention. In other words, the definition included so-called time-loss injuries (stoppage of a bout) as used in the NCAA Injury Surveillance System [ 15 ]. Injury rates were calculated from matches fought using the basic rate formula: (# injuries / # athlete-exposures) × 1,000 = # injuries per 1,000 athlete-exposures (A-E). The Colorado concussion classification was utilized in management of the concussions [ 16 , 17 ]. According to this classification, a first degree concussion is identified by confusion, no loss of memory and no loss of consciousness (LOC). A second degree involves confusion, loss of memory but no LOC and the third degree is when there is LOC [ 16 , 17 ].
Methods
Subjects (219 males and 99 females) participated in the 1997 Canadian National Taekwondo Championships in Toronto, Canada. Injuries were recorded on an injury form to document any injury seen and treatment provided by the health care team as it was required by law. The first author was the only person who kept the injury forms and entered the data, therefore, keeping the identity of athletes confidential. Oral consent was obtained from the athletes for assessment and providing therapy. Data describe the athlete and nature, site, severity and mechanism of the injury. No reliability and validity information for the instrument is available and this study was carried out to pre-test the injury data collection form (Figure  1 ).Injuries were diagnosed by the tournament physician (MK), who has been the national team chiropractic physician for several years and is an experienced (black belt) Taekwondo athlete himself. One injury form was filled out by the attending physician for each time the athlete reported a new injury. However, at each presentation there could be more than one injury reported on the same Injury Report form. For the purposes of this study, an athlete was considered injured if any of the following conditions applied [ 14 ]: 1) any circumstance that forced the Taekwondo athlete to leave the competition; 2) any circumstance for which the referee or athlete had to stop competition; 3) any circumstance for which the athlete requested medical attention. In other words, the definition included so-called time-loss injuries (stoppage of a bout) as used in the NCAA Injury Surveillance System [ 15 ].Injury rates were calculated from matches fought using the basic rate formula: (# injuries / # athlete-exposures) × 1,000 = # injuries per 1,000 athlete-exposures (A-E). The Colorado concussion classification was utilized in management of the concussions [ 16 , 17 ]. According to this classification, a first degree concussion is identified by confusion, no loss of memory and no loss of consciousness (LOC). A second degree involves confusion, loss of memory but no LOC and the third degree is when there is LOC [ 16 , 17 ].Results The age range for the males was 17–34 years with a mean of 24.2 years and for the females, 16–26 years with a mean of 21 years. The age was not recorded for 3 males and 1 female. Table  1  displays the injury data and rates for the Canadian Taekwondo athletes. The lower extremities were the most commonly injured body region in the men (32.0 /1,000 A-E), followed by the face (eyes, nose, cheek, lips, jaw; 18.3/1,000 A-E), and the spine (neck, upper back, low back and coccyx) (13.8/1,000 A-E). If the head and neck (which includes the face area) are combined, as was done in other studies [ 4 , 7 ], this body region incurred the second highest injury rate: 24.9/1,000 A-E. All injuries to the women were sustained to the lower extremities with the foot incurring most of the injuries (15.2/1,000 A-E; Table  2 ). The top five injuries in the males include the sprain (22.8/1,000 A-E), followed by the joint dysfunction (13.7/1,000 A-E), contusion and laceration (11.4/1,000 A-E each), and strain (9.1/1,000 A-E). The cerebral concussion is ranked sixth (6.9/1,000 A-E). There were one third degree and two first degree concussions. In the women, the contusion was the most often occurring injury (15.2/1,000 A-E), followed by the sprain and strain (5.1/1,000 A-E each; Table  3 ). Table  4  displays the rates of the injury mechanisms by gender. Receiving a kick by the men included those connecting with the head/face (18.3/1,000 A-E), trunk (6.9/1,000 A-E), and thigh (2.3/1,000 A-E). Delivering a kick as an injury mechanism in the men included, among others, kicking to the elbow (6.9/1,000 A-E), kicking with the toes, to the trunk and with the knee (2.3/1,000 A-E each). In the women, delivering a kick (10.1/1,000 A-E) was the main injury mechanism and comprised kicks to the elbow, while the kick that was received involved a knee kick.
Results
The age range for the males was 17–34 years with a mean of 24.2 years and for the females, 16–26 years with a mean of 21 years. The age was not recorded for 3 males and 1 female. Table  1  displays the injury data and rates for the Canadian Taekwondo athletes.The lower extremities were the most commonly injured body region in the men (32.0 /1,000 A-E), followed by the face (eyes, nose, cheek, lips, jaw; 18.3/1,000 A-E), and the spine (neck, upper back, low back and coccyx) (13.8/1,000 A-E). If the head and neck (which includes the face area) are combined, as was done in other studies [ 4 , 7 ], this body region incurred the second highest injury rate: 24.9/1,000 A-E. All injuries to the women were sustained to the lower extremities with the foot incurring most of the injuries (15.2/1,000 A-E; Table  2 ).The top five injuries in the males include the sprain (22.8/1,000 A-E), followed by the joint dysfunction (13.7/1,000 A-E), contusion and laceration (11.4/1,000 A-E each), and strain (9.1/1,000 A-E). The cerebral concussion is ranked sixth (6.9/1,000 A-E). There were one third degree and two first degree concussions. In the women, the contusion was the most often occurring injury (15.2/1,000 A-E), followed by the sprain and strain (5.1/1,000 A-E each; Table  3 ).Table  4  displays the rates of the injury mechanisms by gender. Receiving a kick by the men included those connecting with the head/face (18.3/1,000 A-E), trunk (6.9/1,000 A-E), and thigh (2.3/1,000 A-E). Delivering a kick as an injury mechanism in the men included, among others, kicking to the elbow (6.9/1,000 A-E), kicking with the toes, to the trunk and with the knee (2.3/1,000 A-E each). In the women, delivering a kick (10.1/1,000 A-E) was the main injury mechanism and comprised kicks to the elbow, while the kick that was received involved a knee kick.Discussion The injuries incurred by the Canadian Taekwondo athletes compare favourably to those found by others. As mentioned above, American elite athletes recorded injury rates of 127.4/1,000 A-E (men) and 90.1/1,000 A-E (women) [ 2 ], while European colleagues had rates of 139.5/1,000 A-E (men) and 96.5/1,000 A-E (women) [ 3 ]. At one Greek national championship, the men (20.6/1,000 A-E) sustained statistically significantly fewer injuries than the women (36.4/1,000 A-E) [ 13 ]. The total injury rate of the Canadian male and female Taekwondo athletes combined, was also lower than that of their African counterparts (86.6/1,000 A-E) [ 7 ]. At an Open British tournament, injury rates of 51.3/1,000 A-E (men) and 47.6/1,000 A-E (women) were reported [ 4 ]. However, the athletes competing at this particular tournament were of sub-elite level. It is hypothesised that injuries may be related to level of skill and experience, although confirmatory research still needs to be carried out [ 18 ]. All competitors were black belts, but no information is available on their experience in Taekwondo and in competition. Future research should include general Taekwondo as well as competition-specific experience in addition to belt level. Comparative data gleaned from prospective studies on other martial arts injuries incurred at single tournaments are depicted in table  5 . In view of the nature of the sport, as alluded to above, it is not surprising to find the lower extremities to sustain most of the injuries as was found in previous studies as well [ 2 , 3 , 13 ]. Within the lower extremities, the foot (i.e., instep) was the most often injured body part, as was the case with the females in the present study, which led to the suggestion for the Taekwondo governing bodies to recommend padding to help decrease injuries to this site [ 22 ]. In karate, on the other hand, the head and neck incur most of the injuries [ 8 , 10 ], while in judo, the upper extremities are more at risk [ 6 , 11 ]. As expected, the contusion was found to be the most frequently occurring injury type in other studies on Taekwondo injuries [e.g., [ 2 , 3 , 13 ]]. The sprain ranked in the top three of most frequently occurring injuries across several tournaments [ 5 ]. The contusion was also the most often occurring injury in karate [ 9 , 10 ], while the epistaxis ranked second in Dutch men and women [ 10 ]. In Finnish elite male karate athletes the laceration was ranked second and the epistaxis in women [ 9 ]. In judo, the strain in men and the abrasion in women were sustained most often [ 11 , 12 ]. Since the sample sizes in the current investigation as well as in the aforementioned karate and judo studies are rather small, more research is needed to arrive at more definitive conclusions. However, differences between the martial arts in terms of techniques used and competition rules undoubtedly play a major role. Of more concern, however, is the occurrence of cerebral concussions. The Canadian males recorded a higher rate than found in American (4.7/1,000 A-E) [ 2 ] and Greek (1.0/1,000 A-E) [ 13 ] elite Taekwondo athletes, but lower than those competing in the 1993 European Cup (15.5/1,000 A-E) [ 3 ] and the 1991 World Championships (15.3/1,000 A-E) [ 23 ]. The Canadians also recorded lower rates than elite Dutch karate athletes (13.2/1,000 A-E) competing under semi-contact rules [ 10 ]. Given the serious implications of these injuries, preventive measures, testing of equipment and follow-up research are urgently needed [e.g., [ 18 ]]. In accordance with what was found previously, the injury mechanisms included both receiving and delivering kicks for men and women alike [ 2 , 5 ]. The men, more than the women, tended to get injured as a result of receiving a kick [ 2 , 3 ]. It is suggested that the technique most likely implicated is the roundhouse kick [ 3 , 4 , 13 ]. Kicking the elbow typically leads to injury, especially if the kick is executed with the instep of the foot, such as when using the roundhouse kick to attack or counter-attack. Yet another reason to implement foot padding, as already mentioned above. In karate, punching is the main injury mechanism for both men and women [ 8 , 10 ], which may be related to the head and neck region being most frequently injured. More research on Canadian Taekwondo athletes of different age groups and skill levels is needed. Age in the present study is not believed to have played a role in the injuries sustained. The injury profile of the Canadians is quite similar to those found in other studies with Taekwondo athletes in their early twenties [ 2 , 3 , 5 ]. Children and juniors in Taekwondo were reported as incurring higher injury rates than adults [ 4 , 13 ]. Future studies should also include time lost due to injury. Joint dysfunction was identified as the second most common injury sustained by male athletes (13.7/1,000 A-E). Haldeman [ 24 ] defines joint dysfunction quoting Drum (1973) as,"Joint mechanics showing area disturbances of function without structural change; subtle joint dysfunctions affecting quality and range of joint motion. They are diagnosed with the aid of motion palpation, as well as stress and motion radiography investigation" [p. 623]. Greenman [ 25 ] states: "Joint dysfunction is characterized by findings of misalignment, relative fixation, loss of normal range-of-motion and end-play, tenderness, and tissue texture abnormality" [p. 13–14]. Although controversial, the term has been used widely in the literature, mostly by chiropractors, physical therapists and occasionally by biomechanists and medical doctors [ 24 - 33 ]. Further studies are required to validate the current finding.
Discussion
The injuries incurred by the Canadian Taekwondo athletes compare favourably to those found by others. As mentioned above, American elite athletes recorded injury rates of 127.4/1,000 A-E (men) and 90.1/1,000 A-E (women) [ 2 ], while European colleagues had rates of 139.5/1,000 A-E (men) and 96.5/1,000 A-E (women) [ 3 ]. At one Greek national championship, the men (20.6/1,000 A-E) sustained statistically significantly fewer injuries than the women (36.4/1,000 A-E) [ 13 ]. The total injury rate of the Canadian male and female Taekwondo athletes combined, was also lower than that of their African counterparts (86.6/1,000 A-E) [ 7 ]. At an Open British tournament, injury rates of 51.3/1,000 A-E (men) and 47.6/1,000 A-E (women) were reported [ 4 ]. However, the athletes competing at this particular tournament were of sub-elite level. It is hypothesised that injuries may be related to level of skill and experience, although confirmatory research still needs to be carried out [ 18 ]. All competitors were black belts, but no information is available on their experience in Taekwondo and in competition. Future research should include general Taekwondo as well as competition-specific experience in addition to belt level. Comparative data gleaned from prospective studies on other martial arts injuries incurred at single tournaments are depicted in table  5 .In view of the nature of the sport, as alluded to above, it is not surprising to find the lower extremities to sustain most of the injuries as was found in previous studies as well [ 2 , 3 , 13 ]. Within the lower extremities, the foot (i.e., instep) was the most often injured body part, as was the case with the females in the present study, which led to the suggestion for the Taekwondo governing bodies to recommend padding to help decrease injuries to this site [ 22 ]. In karate, on the other hand, the head and neck incur most of the injuries [ 8 , 10 ], while in judo, the upper extremities are more at risk [ 6 , 11 ].As expected, the contusion was found to be the most frequently occurring injury type in other studies on Taekwondo injuries [e.g., [ 2 , 3 , 13 ]]. The sprain ranked in the top three of most frequently occurring injuries across several tournaments [ 5 ]. The contusion was also the most often occurring injury in karate [ 9 , 10 ], while the epistaxis ranked second in Dutch men and women [ 10 ]. In Finnish elite male karate athletes the laceration was ranked second and the epistaxis in women [ 9 ]. In judo, the strain in men and the abrasion in women were sustained most often [ 11 , 12 ]. Since the sample sizes in the current investigation as well as in the aforementioned karate and judo studies are rather small, more research is needed to arrive at more definitive conclusions. However, differences between the martial arts in terms of techniques used and competition rules undoubtedly play a major role.Of more concern, however, is the occurrence of cerebral concussions. The Canadian males recorded a higher rate than found in American (4.7/1,000 A-E) [ 2 ] and Greek (1.0/1,000 A-E) [ 13 ] elite Taekwondo athletes, but lower than those competing in the 1993 European Cup (15.5/1,000 A-E) [ 3 ] and the 1991 World Championships (15.3/1,000 A-E) [ 23 ]. The Canadians also recorded lower rates than elite Dutch karate athletes (13.2/1,000 A-E) competing under semi-contact rules [ 10 ]. Given the serious implications of these injuries, preventive measures, testing of equipment and follow-up research are urgently needed [e.g., [ 18 ]].In accordance with what was found previously, the injury mechanisms included both receiving and delivering kicks for men and women alike [ 2 , 5 ]. The men, more than the women, tended to get injured as a result of receiving a kick [ 2 , 3 ]. It is suggested that the technique most likely implicated is the roundhouse kick [ 3 , 4 , 13 ]. Kicking the elbow typically leads to injury, especially if the kick is executed with the instep of the foot, such as when using the roundhouse kick to attack or counter-attack. Yet another reason to implement foot padding, as already mentioned above. In karate, punching is the main injury mechanism for both men and women [ 8 , 10 ], which may be related to the head and neck region being most frequently injured.More research on Canadian Taekwondo athletes of different age groups and skill levels is needed. Age in the present study is not believed to have played a role in the injuries sustained. The injury profile of the Canadians is quite similar to those found in other studies with Taekwondo athletes in their early twenties [ 2 , 3 , 5 ]. Children and juniors in Taekwondo were reported as incurring higher injury rates than adults [ 4 , 13 ]. Future studies should also include time lost due to injury.Joint dysfunction was identified as the second most common injury sustained by male athletes (13.7/1,000 A-E). Haldeman [ 24 ] defines joint dysfunction quoting Drum (1973) as,"Joint mechanics showing area disturbances of function without structural change; subtle joint dysfunctions affecting quality and range of joint motion. They are diagnosed with the aid of motion palpation, as well as stress and motion radiography investigation" [p. 623]. Greenman [ 25 ] states: "Joint dysfunction is characterized by findings of misalignment, relative fixation, loss of normal range-of-motion and end-play, tenderness, and tissue texture abnormality" [p. 13–14]. Although controversial, the term has been used widely in the literature, mostly by chiropractors, physical therapists and occasionally by biomechanists and medical doctors [ 24 - 33 ]. Further studies are required to validate the current finding.Conclusion The total injury rates for the Canadian Taekwondo athletes compare favourably to those reported in the literature, which is contrary to what was expected based on such a small sample size. It is hypothesized that recent rule changes may have contributed to these relatively low rates when compared to those found for other single tournaments, although more research is indicated before a definitive conclusion may be drawn. Interestingly, joint dysfunction was identified for the first time, which warrants more study. The injury data collection form should also include the technique used as a specification of the injury mechanism. General Taekwondo and competition-specific experience in addition to belt rank should also be recorded.
Conclusion
The total injury rates for the Canadian Taekwondo athletes compare favourably to those reported in the literature, which is contrary to what was expected based on such a small sample size. It is hypothesized that recent rule changes may have contributed to these relatively low rates when compared to those found for other single tournaments, although more research is indicated before a definitive conclusion may be drawn. Interestingly, joint dysfunction was identified for the first time, which warrants more study. The injury data collection form should also include the technique used as a specification of the injury mechanism. General Taekwondo and competition-specific experience in addition to belt rank should also be recorded.Competing interest None declared.
Competing interest
None declared.Authors' contributions MK collected the data, designed the Injury Report form, and wrote the initial draft of the manuscript. WP did the result part, revised and proof read the manuscript.
Authors' contributions
MK collected the data, designed the Injury Report form, and wrote the initial draft of the manuscript. WP did the result part, revised and proof read the manuscript.Pre-publication history The pre-publication history for this paper can be accessed here:
Pre-publication history
The pre-publication history for this paper can be accessed here:


Background wFleaBase is a database with the necessary infrastructure to curate, archive and share genetic, molecular and functional genomic data and protocols for an emerging model organism, the microcrustacean  Daphnia . Commonly known as the water-flea,  Daphnia 's ecological merit is unequaled among metazoans, largely because of its sentinel role within freshwater ecosystems and over 200 years of biological investigations. By consequence, the  Daphnia  Genomics Consortium (DGC) has launched an interdisciplinary research program to create the resources needed to study genes that affect ecological and evolutionary success in natural environments.
Background
wFleaBase is a database with the necessary infrastructure to curate, archive and share genetic, molecular and functional genomic data and protocols for an emerging model organism, the microcrustacean  Daphnia . Commonly known as the water-flea,  Daphnia 's ecological merit is unequaled among metazoans, largely because of its sentinel role within freshwater ecosystems and over 200 years of biological investigations. By consequence, the  Daphnia  Genomics Consortium (DGC) has launched an interdisciplinary research program to create the resources needed to study genes that affect ecological and evolutionary success in natural environments.DaphniaDaphniaDaphniaDiscussion These tools include the genome database wFleaBase, which currently contains functions to search and extract information from expressed sequenced tags, genome survey sequences and full genome sequencing projects. This new database is built primarily from core components of the Generic Model Organism Database project, and related bioinformatics tools.
Discussion
These tools include the genome database wFleaBase, which currently contains functions to search and extract information from expressed sequenced tags, genome survey sequences and full genome sequencing projects. This new database is built primarily from core components of the Generic Model Organism Database project, and related bioinformatics tools.Summary Over the coming year, preliminary genetic maps and the nearly complete genomic sequence of  Daphnia pulex  will be integrated into wFleaBase, including gene predictions and ortholog assignments based on sequence similarities with eukaryote genes of known function. wFleaBase aims to serve a large ecological and evolutionary research community. Our challenge is to rapidly expand its content and to ultimately integrate genetic and functional genomic information with population-level responses to environmental challenges. URL:  .
Summary
Over the coming year, preliminary genetic maps and the nearly complete genomic sequence of  Daphnia pulex  will be integrated into wFleaBase, including gene predictions and ortholog assignments based on sequence similarities with eukaryote genes of known function. wFleaBase aims to serve a large ecological and evolutionary research community. Our challenge is to rapidly expand its content and to ultimately integrate genetic and functional genomic information with population-level responses to environmental challenges. URL:  .Daphnia pulex

Background The micro-crustacean  Daphnia  is a ubiquitous resident of inland waters within all continents of the globe and is the subject of study for numerous biological disciplines including limnology, ecology, physiology, toxicology, population genetics and evolution. Many attributes make this organism an ideal model for ecological and evolutionary genomics research. As the principal grazers of algae and the primary forage of fish,  Daphnia  are key members of aquatic food webs and are easily sampled in great numbers. These animals inhabit remarkably diverse environments and show striking patterns of convergent evolution linked to specific habitat transitions [ 1 ]. Their mode of reproduction (cyclical parthenogenesis) is convenient for experimental genetics, providing both long-term clonal lineages and controlled outbred populations by manipulating the environmental cues required for the induction of male production and for mating [ 2 ]. Yet most notably,  Daphnia  offer unprecedented opportunities to study historical responses to environmental change, by harvesting, dating and resurrecting annually sedimented diapausing eggs within lacustrine basins and by competing past products of evolution against their modern descendents [ 3 , 4 ]. For these reasons, an international network of investigators is creating community resources, already proven to effectively promote genomic-scale investigations in other disciplines (molecular, cell and developmental biology), with a goal to understand connections between genome structure, gene expression, individual fitness and population-level responses to environmental challenges. wFleaBase is a project of the  Daphnia  Genomics Consortium [ 5 ] and is designed to be a resource where users can search and retrieve sequence data for genes of ecological importance, or find putative genes modulating traits of interest based on their homologies to functionally characterized genes in other model organisms. Therefore, wFleaBase is an organized repository of  Daphnia  specific sequences with standard bioinformatic tools to facilitate gene discovery. This function includes BLAST analyses and links to gene reports for other eukaryotic genomic models via euGenes [ 6 ]. However, for most of these other model species, characterized genes are ineluctably biased toward those sets whose phenotypic effects are observed in the benign settings of a laboratory. With the additional goal of elucidating the function of novel genes with environment-specific expression patterns, wFleaBase is also designed to help locate genes with no known functions. For this purpose, a pipeline of bioinformatic tools is created to supply DNA markers from raw sequence trace files. Genetic map information on the location of variable DNA markers will soon be presented, allowing researchers to systematically screen genomic regions for the presence of quantitative trait loci (QTL) by using the available markers in their studies. Finally, to facilitate subsequent gene-specific capture by positional cloning, catalogues of available arrayed DNA libraries are displayed within the DGC web pages. The main sources of data for wFleaBase are direct submissions from DGC members and from research at large genome sequencing centers. The latest data can be accessed by web browser at   and Internet file transfer at  .
Background
The micro-crustacean  Daphnia  is a ubiquitous resident of inland waters within all continents of the globe and is the subject of study for numerous biological disciplines including limnology, ecology, physiology, toxicology, population genetics and evolution. Many attributes make this organism an ideal model for ecological and evolutionary genomics research. As the principal grazers of algae and the primary forage of fish,  Daphnia  are key members of aquatic food webs and are easily sampled in great numbers. These animals inhabit remarkably diverse environments and show striking patterns of convergent evolution linked to specific habitat transitions [ 1 ]. Their mode of reproduction (cyclical parthenogenesis) is convenient for experimental genetics, providing both long-term clonal lineages and controlled outbred populations by manipulating the environmental cues required for the induction of male production and for mating [ 2 ]. Yet most notably,  Daphnia  offer unprecedented opportunities to study historical responses to environmental change, by harvesting, dating and resurrecting annually sedimented diapausing eggs within lacustrine basins and by competing past products of evolution against their modern descendents [ 3 , 4 ]. For these reasons, an international network of investigators is creating community resources, already proven to effectively promote genomic-scale investigations in other disciplines (molecular, cell and developmental biology), with a goal to understand connections between genome structure, gene expression, individual fitness and population-level responses to environmental challenges.DaphniaDaphniaDaphniawFleaBase is a project of the  Daphnia  Genomics Consortium [ 5 ] and is designed to be a resource where users can search and retrieve sequence data for genes of ecological importance, or find putative genes modulating traits of interest based on their homologies to functionally characterized genes in other model organisms. Therefore, wFleaBase is an organized repository of  Daphnia  specific sequences with standard bioinformatic tools to facilitate gene discovery. This function includes BLAST analyses and links to gene reports for other eukaryotic genomic models via euGenes [ 6 ]. However, for most of these other model species, characterized genes are ineluctably biased toward those sets whose phenotypic effects are observed in the benign settings of a laboratory. With the additional goal of elucidating the function of novel genes with environment-specific expression patterns, wFleaBase is also designed to help locate genes with no known functions. For this purpose, a pipeline of bioinformatic tools is created to supply DNA markers from raw sequence trace files. Genetic map information on the location of variable DNA markers will soon be presented, allowing researchers to systematically screen genomic regions for the presence of quantitative trait loci (QTL) by using the available markers in their studies. Finally, to facilitate subsequent gene-specific capture by positional cloning, catalogues of available arrayed DNA libraries are displayed within the DGC web pages.DaphniaDaphniaThe main sources of data for wFleaBase are direct submissions from DGC members and from research at large genome sequencing centers. The latest data can be accessed by web browser at   and Internet file transfer at  .Construction and content Generic genome database This service is built using tested genome database components and open source software that are shared in common with several other databases. Middleware in Perl and Java are added to bring together BLAST, sequence reports, searches and other bioinformatics programs for web access. The Indiana University Genome Informatics Laboratory houses wFleaBase, along with related genome databases FlyBase [ 7 ] and euGenes [ 8 ]. In the last two years, this work is coalescing with sister organism database projects under the umbrella of Generic Model Organism Database project (GMOD [ 9 ]). The relational database from GMOD [ 10 ] used for FlyBase and wFleaBase is named Chado (after "the Way of Tea" ceremony). It includes a schema for structuring a growing range of genome information, works with the free PostgreSQL database package (among others), and includes a Chado XML exchange format and tools. Significantly, a community of bioinformaticians is sharing development and use of these components. Another project that has made wFleaBase simple to start is Argos (D.G. Gilbert et al., in preparation [ 11 ]), a framework for building and distributing genome databases, with pre-configured core components listed in Table  1 . A third basic GMOD component of wFleaBase is LuceGene (D.G. Gilbert et al., in preparation), which provides rapid, data object-oriented searches, with data and document retrieval of a wide range of genome information. To start wFleaBase, we copied a genome database/web server template from Argos infrastructure, including Chado database and genome informatics tools, loaded the database with a first set of sequences, and produced BLAST comparisons of these against 10 other eukaryote genomes from the euGenes project. The euGenes project provides a standard summary of gene and genome information from eukaryotic organisms, and includes over 200,000 named genes and their functions, with 900,000 genome features. This eukaryote genome collection allows new genomes (like  Daphnia 's) to be matched by sequence similarity, then annotated with reference gene information. When  Daphnia  or other new organism sequences are matched to this data, it suggests their gene function and provides starting points for experiments into their ecological and evolutionary genetic significance. wFleaBase records and accession numbers Sequences are assigned unique and stable accession numbers upon entry into the Chado database, which are organized into seven divisions according to whether they are derived from genome survey sequences (GSS), expressed sequence tags (EST) or high-throughput genomic (HG) and cDNA (HC) projects.  Daphnia  sequences from other public databases (PB), mitochondrial sequences from molecular systematic studies of the genus (MT) and amplicons of microsatellite DNA markers (MS) are also categorized. To date, wFleaBase contains 14,451 records, including EST (WFes0000001-WFes0012408), GSS (WFgs0000001-WFgs0001495) and MS (WFms0000001-WFms0000548) sequences. Each sequence header provides a short description on the type of sequence, the species and strain from which the sequence was obtained, the library identification code for the cloned fragment with synonyms and contact name. Full contact information is provided elsewhere [ 12 ]. For convenience, sequences can be downloaded in fasta format from each division via the FTP service or by navigating to specific Data sub-directories of the Genomics hyperlink, which is printed on the side menu of the web pages. At this moment, researchers are requested to send new  Daphnia  sequences to the corresponding author, for processing and archiving the data into wFleaBase. Submissions undergo quality assurance checks for vector contamination and correct taxonomy before they enter the database.
Construction and content
Generic genome database This service is built using tested genome database components and open source software that are shared in common with several other databases. Middleware in Perl and Java are added to bring together BLAST, sequence reports, searches and other bioinformatics programs for web access. The Indiana University Genome Informatics Laboratory houses wFleaBase, along with related genome databases FlyBase [ 7 ] and euGenes [ 8 ]. In the last two years, this work is coalescing with sister organism database projects under the umbrella of Generic Model Organism Database project (GMOD [ 9 ]). The relational database from GMOD [ 10 ] used for FlyBase and wFleaBase is named Chado (after "the Way of Tea" ceremony). It includes a schema for structuring a growing range of genome information, works with the free PostgreSQL database package (among others), and includes a Chado XML exchange format and tools. Significantly, a community of bioinformaticians is sharing development and use of these components. Another project that has made wFleaBase simple to start is Argos (D.G. Gilbert et al., in preparation [ 11 ]), a framework for building and distributing genome databases, with pre-configured core components listed in Table  1 . A third basic GMOD component of wFleaBase is LuceGene (D.G. Gilbert et al., in preparation), which provides rapid, data object-oriented searches, with data and document retrieval of a wide range of genome information. To start wFleaBase, we copied a genome database/web server template from Argos infrastructure, including Chado database and genome informatics tools, loaded the database with a first set of sequences, and produced BLAST comparisons of these against 10 other eukaryote genomes from the euGenes project. The euGenes project provides a standard summary of gene and genome information from eukaryotic organisms, and includes over 200,000 named genes and their functions, with 900,000 genome features. This eukaryote genome collection allows new genomes (like  Daphnia 's) to be matched by sequence similarity, then annotated with reference gene information. When  Daphnia  or other new organism sequences are matched to this data, it suggests their gene function and provides starting points for experiments into their ecological and evolutionary genetic significance.
Generic genome database
This service is built using tested genome database components and open source software that are shared in common with several other databases. Middleware in Perl and Java are added to bring together BLAST, sequence reports, searches and other bioinformatics programs for web access. The Indiana University Genome Informatics Laboratory houses wFleaBase, along with related genome databases FlyBase [ 7 ] and euGenes [ 8 ]. In the last two years, this work is coalescing with sister organism database projects under the umbrella of Generic Model Organism Database project (GMOD [ 9 ]). The relational database from GMOD [ 10 ] used for FlyBase and wFleaBase is named Chado (after "the Way of Tea" ceremony). It includes a schema for structuring a growing range of genome information, works with the free PostgreSQL database package (among others), and includes a Chado XML exchange format and tools. Significantly, a community of bioinformaticians is sharing development and use of these components. Another project that has made wFleaBase simple to start is Argos (D.G. Gilbert et al., in preparation [ 11 ]), a framework for building and distributing genome databases, with pre-configured core components listed in Table  1 . A third basic GMOD component of wFleaBase is LuceGene (D.G. Gilbert et al., in preparation), which provides rapid, data object-oriented searches, with data and document retrieval of a wide range of genome information.To start wFleaBase, we copied a genome database/web server template from Argos infrastructure, including Chado database and genome informatics tools, loaded the database with a first set of sequences, and produced BLAST comparisons of these against 10 other eukaryote genomes from the euGenes project. The euGenes project provides a standard summary of gene and genome information from eukaryotic organisms, and includes over 200,000 named genes and their functions, with 900,000 genome features. This eukaryote genome collection allows new genomes (like  Daphnia 's) to be matched by sequence similarity, then annotated with reference gene information. When  Daphnia  or other new organism sequences are matched to this data, it suggests their gene function and provides starting points for experiments into their ecological and evolutionary genetic significance.DaphniaDaphniawFleaBase records and accession numbers Sequences are assigned unique and stable accession numbers upon entry into the Chado database, which are organized into seven divisions according to whether they are derived from genome survey sequences (GSS), expressed sequence tags (EST) or high-throughput genomic (HG) and cDNA (HC) projects.  Daphnia  sequences from other public databases (PB), mitochondrial sequences from molecular systematic studies of the genus (MT) and amplicons of microsatellite DNA markers (MS) are also categorized. To date, wFleaBase contains 14,451 records, including EST (WFes0000001-WFes0012408), GSS (WFgs0000001-WFgs0001495) and MS (WFms0000001-WFms0000548) sequences. Each sequence header provides a short description on the type of sequence, the species and strain from which the sequence was obtained, the library identification code for the cloned fragment with synonyms and contact name. Full contact information is provided elsewhere [ 12 ]. For convenience, sequences can be downloaded in fasta format from each division via the FTP service or by navigating to specific Data sub-directories of the Genomics hyperlink, which is printed on the side menu of the web pages. At this moment, researchers are requested to send new  Daphnia  sequences to the corresponding author, for processing and archiving the data into wFleaBase. Submissions undergo quality assurance checks for vector contamination and correct taxonomy before they enter the database.
wFleaBase records and accession numbers
Sequences are assigned unique and stable accession numbers upon entry into the Chado database, which are organized into seven divisions according to whether they are derived from genome survey sequences (GSS), expressed sequence tags (EST) or high-throughput genomic (HG) and cDNA (HC) projects.  Daphnia  sequences from other public databases (PB), mitochondrial sequences from molecular systematic studies of the genus (MT) and amplicons of microsatellite DNA markers (MS) are also categorized. To date, wFleaBase contains 14,451 records, including EST (WFes0000001-WFes0012408), GSS (WFgs0000001-WFgs0001495) and MS (WFms0000001-WFms0000548) sequences. Each sequence header provides a short description on the type of sequence, the species and strain from which the sequence was obtained, the library identification code for the cloned fragment with synonyms and contact name. Full contact information is provided elsewhere [ 12 ]. For convenience, sequences can be downloaded in fasta format from each division via the FTP service or by navigating to specific Data sub-directories of the Genomics hyperlink, which is printed on the side menu of the web pages. At this moment, researchers are requested to send new  Daphnia  sequences to the corresponding author, for processing and archiving the data into wFleaBase. Submissions undergo quality assurance checks for vector contamination and correct taxonomy before they enter the database.DaphniaDaphniaUtility Gene searching and discovery As an information and gene discovery system, wFleaBase focuses on providing efficient tools for searching and retrieving records of interest. Its current features are best highlighted by co-navigating the web pages along with a user interested in locating ecologically relevant genes, for example, genes that confer resistance to elevated levels of ultra-violet radiation encountered by closely related species to  D. pulex . Beginning at the welcome page, the user can navigate via the hyperlink located at the top menu towards the Blast page of wFleaBase   to perform sequence-similarity searches on the archived data using the BLAST family of programs. The user enters a nucleotide sequence, whose gene function is well characterized and evolutionarily conserved, with a goal to find the homologous gene in  Daphnia . For example, a  Drosophila melanogaster  mRNA sequence obtained from GenBank (NM 165564) or from FlyBase (FBgn0003082) for the gene  photorepair  is used to query all  Daphnia  sequences using the default settings of the tblastx program. Alternatively, the user can select to query species-specific GSS or EST databases. This search retrieves record WFgs0000440, which is a 917 nucleotide sequence with a best match score of 83 bits and an E-value of 5e-45. Using this information, the user can then download the  Daphnia  sequence onto their personal computers as a text file, design primers using their own software to probe the arrayed  Daphnia  cosmid library by the Polymerase Chain Reaction (PCR), identify bacterial clones containing the gene, and characterize the entire locus by sequencing. Indeed, this specific exercise identifies at least three cosmids (out of 37,000) containing a likely homologue to  photorepair  from  Drosophila  [ 13 ]. Returning to the welcome page, the user can instead choose to explore tables containing data extracted from automated BLAST searches against the euGenes database, which includes annotated genome sequences from 10 eukaryotic model organisms. Although this option for gene searching is more tedious, it does allow users to focus precisely on the data currently available in wFleaBase. Four tables of BLAST results are offered at   by following the "Genomics" hyperlinks located at the top and side menus. At present,  Daphnia  EST and GSS sequences are each compared to the protein coding genes and to genomic sequences in euGenes. Many options exist for sorting the BLAST tables. The user can specify what BLAST result columns to show, and can sort these columns based on the ascending or descending order of their entries. The tables can also include BLAST results against all organisms within euGenes or the tables can be filtered to include results from comparisons against a single taxon. For example, the same user, now looking to find a  Daphnia  homologue to genes known to confer salt-resistance to species inhabiting saline environments, begins by searching for names or euGenes accession numbers of functionally related genes within the Blast tables using the wFleaBase search function located in the top menu of the Blast tables. If the user chooses to search for "ATPα", which is a sodium/potassium-exchanging ATPase shown to be under positive selection in brine shrimp populations adapted to ultra-saline waters [ 14 ], 11 EST records that match ATPα in fly are discovered with bit scores and E-values ranging from 42.36 and 0.002 to 327.0 and 2.2e-89. The user can retrieve the  Daphnia  sequences via hyperlinks located in the first column of the search results, or further uncover the extent of evolutionary conservation for this gene by examining the euGene Reports, also via hyperlinks located in the last column. Alternatively, if the user chooses to use the FlyBase accession number for this gene (FBgn0002921) to retrieve  Daphnia  homologues using the search function, the same 11 records are obtained. Tools for hunting unknown genes Although effective, the candidate gene approach to finding  Daphnia  genes of ecological interest is limited by the levels of sequence and functional conservation among characterized genes in other model organisms. Work is underway by the DGC to create the required tools for identifying ecologically relevant genes by positional mapping using microsatellite markers. wFleaBase presently archives 528 microsatellite markers [ 15 ]. Yet, to generate additional loci for genetic mapping in  D. pulex  and  D. magna , wFleaBase integrates a suite of computational programs that (i) identifies microsatellites from raw DNA sequencer trace files, (ii) designs optimal primers for amplifying the markers and (iii) indexes the amplicon, microsatellite motifs and primer information into the Microsat database [ 16 ]. The Microsat database will rapidly grow by applying this pipeline to trace files emerging from the  Daphnia  genome sequencing project. The wFleaBase search function wFleaBase uses LuceGene to support rapid search and retrieval of the sequence database, of Blast table entries, of  Daphnia  Medline references and of  Daphnia  web documents. LuceGene [ 17 ], based on the Lucene [ 18 ] search system, is an open-source part of the GMOD project. A major benefit of LuceGene is the large variety of data formats that can be added to the search system with minimal work. For instance, currently supported formats used in wFleaBase include Simple text, XML (Medline abstracts and Gene sequence annotation), HTML, Tabular data, Bio-formats (Fasta, GenBank, EMBL) and Gene object data used by euGenes. Search terms such as "magna" to retrieve all sequences from this species, can be entered in a Search box at the head of all web pages. The search is refined at the main wFleaBase search page by specifying the search library (sequences, references, documents or Blast tables) and the library fields containing the queried term. Options are also available to detail the output format, and each result is hyperlinked to the source document for easy access to the data. On a separate web page (Batch download), users can recover multiple records obtained from complex queries and save the results to a file.
Utility
Gene searching and discovery As an information and gene discovery system, wFleaBase focuses on providing efficient tools for searching and retrieving records of interest. Its current features are best highlighted by co-navigating the web pages along with a user interested in locating ecologically relevant genes, for example, genes that confer resistance to elevated levels of ultra-violet radiation encountered by closely related species to  D. pulex . Beginning at the welcome page, the user can navigate via the hyperlink located at the top menu towards the Blast page of wFleaBase   to perform sequence-similarity searches on the archived data using the BLAST family of programs. The user enters a nucleotide sequence, whose gene function is well characterized and evolutionarily conserved, with a goal to find the homologous gene in  Daphnia . For example, a  Drosophila melanogaster  mRNA sequence obtained from GenBank (NM 165564) or from FlyBase (FBgn0003082) for the gene  photorepair  is used to query all  Daphnia  sequences using the default settings of the tblastx program. Alternatively, the user can select to query species-specific GSS or EST databases. This search retrieves record WFgs0000440, which is a 917 nucleotide sequence with a best match score of 83 bits and an E-value of 5e-45. Using this information, the user can then download the  Daphnia  sequence onto their personal computers as a text file, design primers using their own software to probe the arrayed  Daphnia  cosmid library by the Polymerase Chain Reaction (PCR), identify bacterial clones containing the gene, and characterize the entire locus by sequencing. Indeed, this specific exercise identifies at least three cosmids (out of 37,000) containing a likely homologue to  photorepair  from  Drosophila  [ 13 ]. Returning to the welcome page, the user can instead choose to explore tables containing data extracted from automated BLAST searches against the euGenes database, which includes annotated genome sequences from 10 eukaryotic model organisms. Although this option for gene searching is more tedious, it does allow users to focus precisely on the data currently available in wFleaBase. Four tables of BLAST results are offered at   by following the "Genomics" hyperlinks located at the top and side menus. At present,  Daphnia  EST and GSS sequences are each compared to the protein coding genes and to genomic sequences in euGenes. Many options exist for sorting the BLAST tables. The user can specify what BLAST result columns to show, and can sort these columns based on the ascending or descending order of their entries. The tables can also include BLAST results against all organisms within euGenes or the tables can be filtered to include results from comparisons against a single taxon. For example, the same user, now looking to find a  Daphnia  homologue to genes known to confer salt-resistance to species inhabiting saline environments, begins by searching for names or euGenes accession numbers of functionally related genes within the Blast tables using the wFleaBase search function located in the top menu of the Blast tables. If the user chooses to search for "ATPα", which is a sodium/potassium-exchanging ATPase shown to be under positive selection in brine shrimp populations adapted to ultra-saline waters [ 14 ], 11 EST records that match ATPα in fly are discovered with bit scores and E-values ranging from 42.36 and 0.002 to 327.0 and 2.2e-89. The user can retrieve the  Daphnia  sequences via hyperlinks located in the first column of the search results, or further uncover the extent of evolutionary conservation for this gene by examining the euGene Reports, also via hyperlinks located in the last column. Alternatively, if the user chooses to use the FlyBase accession number for this gene (FBgn0002921) to retrieve  Daphnia  homologues using the search function, the same 11 records are obtained.
Gene searching and discovery
As an information and gene discovery system, wFleaBase focuses on providing efficient tools for searching and retrieving records of interest. Its current features are best highlighted by co-navigating the web pages along with a user interested in locating ecologically relevant genes, for example, genes that confer resistance to elevated levels of ultra-violet radiation encountered by closely related species to  D. pulex . Beginning at the welcome page, the user can navigate via the hyperlink located at the top menu towards the Blast page of wFleaBase   to perform sequence-similarity searches on the archived data using the BLAST family of programs. The user enters a nucleotide sequence, whose gene function is well characterized and evolutionarily conserved, with a goal to find the homologous gene in  Daphnia . For example, a  Drosophila melanogaster  mRNA sequence obtained from GenBank (NM 165564) or from FlyBase (FBgn0003082) for the gene  photorepair  is used to query all  Daphnia  sequences using the default settings of the tblastx program. Alternatively, the user can select to query species-specific GSS or EST databases. This search retrieves record WFgs0000440, which is a 917 nucleotide sequence with a best match score of 83 bits and an E-value of 5e-45. Using this information, the user can then download the  Daphnia  sequence onto their personal computers as a text file, design primers using their own software to probe the arrayed  Daphnia  cosmid library by the Polymerase Chain Reaction (PCR), identify bacterial clones containing the gene, and characterize the entire locus by sequencing. Indeed, this specific exercise identifies at least three cosmids (out of 37,000) containing a likely homologue to  photorepair  from  Drosophila  [ 13 ].D. pulexDaphniaDrosophila melanogasterphotorepairDaphniaDaphniaDaphniaphotorepairDrosophilaReturning to the welcome page, the user can instead choose to explore tables containing data extracted from automated BLAST searches against the euGenes database, which includes annotated genome sequences from 10 eukaryotic model organisms. Although this option for gene searching is more tedious, it does allow users to focus precisely on the data currently available in wFleaBase. Four tables of BLAST results are offered at   by following the "Genomics" hyperlinks located at the top and side menus. At present,  Daphnia  EST and GSS sequences are each compared to the protein coding genes and to genomic sequences in euGenes. Many options exist for sorting the BLAST tables. The user can specify what BLAST result columns to show, and can sort these columns based on the ascending or descending order of their entries. The tables can also include BLAST results against all organisms within euGenes or the tables can be filtered to include results from comparisons against a single taxon. For example, the same user, now looking to find a  Daphnia  homologue to genes known to confer salt-resistance to species inhabiting saline environments, begins by searching for names or euGenes accession numbers of functionally related genes within the Blast tables using the wFleaBase search function located in the top menu of the Blast tables. If the user chooses to search for "ATPα", which is a sodium/potassium-exchanging ATPase shown to be under positive selection in brine shrimp populations adapted to ultra-saline waters [ 14 ], 11 EST records that match ATPα in fly are discovered with bit scores and E-values ranging from 42.36 and 0.002 to 327.0 and 2.2e-89. The user can retrieve the  Daphnia  sequences via hyperlinks located in the first column of the search results, or further uncover the extent of evolutionary conservation for this gene by examining the euGene Reports, also via hyperlinks located in the last column. Alternatively, if the user chooses to use the FlyBase accession number for this gene (FBgn0002921) to retrieve  Daphnia  homologues using the search function, the same 11 records are obtained.DaphniaDaphniaDaphniaDaphniaTools for hunting unknown genes Although effective, the candidate gene approach to finding  Daphnia  genes of ecological interest is limited by the levels of sequence and functional conservation among characterized genes in other model organisms. Work is underway by the DGC to create the required tools for identifying ecologically relevant genes by positional mapping using microsatellite markers. wFleaBase presently archives 528 microsatellite markers [ 15 ]. Yet, to generate additional loci for genetic mapping in  D. pulex  and  D. magna , wFleaBase integrates a suite of computational programs that (i) identifies microsatellites from raw DNA sequencer trace files, (ii) designs optimal primers for amplifying the markers and (iii) indexes the amplicon, microsatellite motifs and primer information into the Microsat database [ 16 ]. The Microsat database will rapidly grow by applying this pipeline to trace files emerging from the  Daphnia  genome sequencing project.
Tools for hunting unknown genes
Although effective, the candidate gene approach to finding  Daphnia  genes of ecological interest is limited by the levels of sequence and functional conservation among characterized genes in other model organisms. Work is underway by the DGC to create the required tools for identifying ecologically relevant genes by positional mapping using microsatellite markers. wFleaBase presently archives 528 microsatellite markers [ 15 ]. Yet, to generate additional loci for genetic mapping in  D. pulex  and  D. magna , wFleaBase integrates a suite of computational programs that (i) identifies microsatellites from raw DNA sequencer trace files, (ii) designs optimal primers for amplifying the markers and (iii) indexes the amplicon, microsatellite motifs and primer information into the Microsat database [ 16 ]. The Microsat database will rapidly grow by applying this pipeline to trace files emerging from the  Daphnia  genome sequencing project.DaphniaD. pulexD. magnaDaphniaThe wFleaBase search function wFleaBase uses LuceGene to support rapid search and retrieval of the sequence database, of Blast table entries, of  Daphnia  Medline references and of  Daphnia  web documents. LuceGene [ 17 ], based on the Lucene [ 18 ] search system, is an open-source part of the GMOD project. A major benefit of LuceGene is the large variety of data formats that can be added to the search system with minimal work. For instance, currently supported formats used in wFleaBase include Simple text, XML (Medline abstracts and Gene sequence annotation), HTML, Tabular data, Bio-formats (Fasta, GenBank, EMBL) and Gene object data used by euGenes. Search terms such as "magna" to retrieve all sequences from this species, can be entered in a Search box at the head of all web pages. The search is refined at the main wFleaBase search page by specifying the search library (sequences, references, documents or Blast tables) and the library fields containing the queried term. Options are also available to detail the output format, and each result is hyperlinked to the source document for easy access to the data. On a separate web page (Batch download), users can recover multiple records obtained from complex queries and save the results to a file.
The wFleaBase search function
wFleaBase uses LuceGene to support rapid search and retrieval of the sequence database, of Blast table entries, of  Daphnia  Medline references and of  Daphnia  web documents. LuceGene [ 17 ], based on the Lucene [ 18 ] search system, is an open-source part of the GMOD project. A major benefit of LuceGene is the large variety of data formats that can be added to the search system with minimal work. For instance, currently supported formats used in wFleaBase include Simple text, XML (Medline abstracts and Gene sequence annotation), HTML, Tabular data, Bio-formats (Fasta, GenBank, EMBL) and Gene object data used by euGenes. Search terms such as "magna" to retrieve all sequences from this species, can be entered in a Search box at the head of all web pages. The search is refined at the main wFleaBase search page by specifying the search library (sequences, references, documents or Blast tables) and the library fields containing the queried term. Options are also available to detail the output format, and each result is hyperlinked to the source document for easy access to the data. On a separate web page (Batch download), users can recover multiple records obtained from complex queries and save the results to a file.DaphniaDaphniaDiscussion and conclusions The wFleaBase project is young. Its future success is linked to the DGC and its goal to develop  Daphnia  into a functional genomics research model, with the added advantage of interpreting observations in the context of natural ecological challenges. wFleaBase is currently designed to facilitate gene discovery for immediate use in research projects. However, the functionality of this service will grow in equal pace with the rapid accumulation of genomics data. Within the next year, this site will host the full genome sequence for  D. pulex  – a collaborative project involving the U.S. Department of Energy Joint Genome Institute, the Environmental Protection Agency and the DGC. Genetic maps for  D. pulex  and  D. magna  are also under construction. Therefore, wFleaBase will soon be enhanced by implementing the CMap module of GMOD and allow users to compare the  Daphnia  genetic and physical maps emerging from current research and to choose the most appropriate set of markers for quantitative trait locus (QTL) mapping projects. Simultaneously, wFleaBase will also assemble cDNA sequences from another large DGC sequencing effort aimed to document most of the  Daphnia  transcriptome.  Daphnia  gene reports will be created in accordance to standards set by current model organism databases [ 19 ]. Gbrowse genome browser and Apollo annotation editor will be used for viewing genome features when they are available. Informatics efforts focus on implementing existing database tools rather than development of new ones, providing a cost-effective genome database for these species. In this way, the current format linking  Daphnia  genomic information to other model species will be reinforced, allowing greater opportunities to apply the candidate gene approach for identifying genes of ecological importance.
Discussion and conclusions
The wFleaBase project is young. Its future success is linked to the DGC and its goal to develop  Daphnia  into a functional genomics research model, with the added advantage of interpreting observations in the context of natural ecological challenges. wFleaBase is currently designed to facilitate gene discovery for immediate use in research projects. However, the functionality of this service will grow in equal pace with the rapid accumulation of genomics data. Within the next year, this site will host the full genome sequence for  D. pulex  – a collaborative project involving the U.S. Department of Energy Joint Genome Institute, the Environmental Protection Agency and the DGC. Genetic maps for  D. pulex  and  D. magna  are also under construction. Therefore, wFleaBase will soon be enhanced by implementing the CMap module of GMOD and allow users to compare the  Daphnia  genetic and physical maps emerging from current research and to choose the most appropriate set of markers for quantitative trait locus (QTL) mapping projects. Simultaneously, wFleaBase will also assemble cDNA sequences from another large DGC sequencing effort aimed to document most of the  Daphnia  transcriptome.  Daphnia  gene reports will be created in accordance to standards set by current model organism databases [ 19 ]. Gbrowse genome browser and Apollo annotation editor will be used for viewing genome features when they are available. Informatics efforts focus on implementing existing database tools rather than development of new ones, providing a cost-effective genome database for these species. In this way, the current format linking  Daphnia  genomic information to other model species will be reinforced, allowing greater opportunities to apply the candidate gene approach for identifying genes of ecological importance.DaphniaD. pulexD. pulexD. magnaDaphniaDaphniaDaphniaDaphniaAvailability and requirements wFleaBase is publicly available and can be accessed at   using web browsers and at   by using internet file transfer protocols.
Availability and requirements
wFleaBase is publicly available and can be accessed at   using web browsers and at   by using internet file transfer protocols.Authors' contributions JC contributed data, web documentation and aided in the overall design and functionality of this database. VS contributed programming for both the database and Blast searches, and contributed to its design and development. DG contributed the generic database framework design, the overall web structure, the euGenes data and built GMOD database and Blast tools. All authors read and approved the final manuscript.
Authors' contributions
JC contributed data, web documentation and aided in the overall design and functionality of this database. VS contributed programming for both the database and Blast searches, and contributed to its design and development. DG contributed the generic database framework design, the overall web structure, the euGenes data and built GMOD database and Blast tools. All authors read and approved the final manuscript.