Comparative evaluation of core muscle recruitment pattern in response to sudden external perturbations in patients with patellofemoral pain syndrome and healthy subjects.
OBJECTIVE
To evaluate the core muscles' electromyographic activity in response to unexpected perturbations to the pelvis in patients with patellofemoral pain syndrome (PFPS) and healthy subjects.


DESIGN
Case-control study.


SETTING
Center for human motion science research.


PARTICIPANTS
Women (N=54) aged 18 to 40 years, including 27 subjects with diagnosed PFPS and 27 healthy controls.


INTERVENTION
An unexpected perturbation was applied to the lateral side of the pelvis by pulling a 1kg medicine ball back to an angle in which releasing the pendulum applied the energy of 20% of the subject's body mass index. This intervention was repeated 3 times with a minimum of 30 seconds of rest between the trials.


MAIN OUTCOME MEASURES
Electromyographic onsets and durations of the transversus abdominis/internal oblique, erector spinae (ES), and gluteus medius (GM) muscles were recorded in response to the unexpected lateral perturbation to the pelvis.


RESULTS
The recruitment pattern of the core muscles was different between the 2 groups. In the subjects with PFPS, the abdominal muscles and the ES activated significantly earlier and longer, whereas the GM responded significantly later than in the controls. The duration of GM activity was not significantly different between the groups.


CONCLUSIONS
The results of this investigation suggest that the core muscles are recruited differently in subjects with PFPS to provide core stability. It appears that core neuromuscular improvement could be an effective strategy in rehabilitation of patients with PFPS.
['Rojhani Shirazi|Zahra|Z|', 'Biabani Moghaddam|Mana|M|', 'Motealleh|Alireza|A|']
D000009:Abdominal Muscles D000293:Adolescent D000328:Adult D001696:Biomechanical Phenomena D015992:Body Mass Index D016022:Case-Control Studies D004576:Electromyography D005260:Female D006801:Humans D009119:Muscle Contraction D018482:Muscle, Skeletal D046788:Patellofemoral Pain Syndrome D010388:Pelvis D055815:Young Adult
Muscles Patellofemoral pain syndrome Rehabilitation Electromyography