The inter-rater reliability of the modified finger goniometer for measuring forearm rotation.
STUDY DESIGN
Prospective cohort study.


PURPOSE OF THE STUDY
To compare the inter-rater reliability of using a modified finger goniometer (MFG) for the measurement of isolated forearm rotation for patients with distal radius fractures to the currently accepted technique for isolated forearm measurement.


INTRODUCTION
The currently accepted method of forearm measurement requires the assessor to visually estimate vertical for the stationary arm and placement of the moveable arm while placing a straight edge along a curved surface. Inter-rater reliability may be limited as assessors may estimate the placement of the goniometer arms differently depending on their experience, posture, and even their positioning relative to the patient. Rather than continue to place a straight edge on a round surface, we evaluate a new technique using an MFG for measuring isolated forearm rotation.


METHODS
Patients with clinically healed distal radius fractures were enrolled in the study. Measurement of active forearm pronation and supination was recorded using 2 separate measurement techniques. These measurements were taken by 2 separate hand therapists with more than 10 years of clinical experience in a tertiary care setting at the beginning and end of hand therapy sessions for 3 consecutive weekly visits. Intraclass correlation coefficients (ICCs), standard error of measurement, and minimal detectable change were calculated for each technique.


RESULTS
The point estimates for the MFG method demonstrated a slightly higher ICC than the standard method for pronation (0.86 vs 0.82). For supination, both measurement techniques displayed equally high pooled ICCs (0.95). The standard error of measurements for the MFG were 2.1 for pronation and 1.2 for supination compared with 2.9 (pronation) and 1.2 (supination) for the standard technique. These translate into 90% minimal detectable changes of 5° and 3° for the MFG pronation/supination compared with 7° (pronation) and 3° (supination) for the standard technique, respectively.


DISCUSSION
Although the point estimates for the ICCs of the MFG method are equal or higher than the standard method, the confidence intervals for the ICCs overlap, indicating that the MFG is at least equivalent to the standard method in terms of inter-rater reliability.


LEVEL OF EVIDENCE
2b.
['Szekeres|Mike|M|', 'MacDermid|Joy C|JC|', 'Birmingham|Trevor|T|', 'Grewal|Ruby|R|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D053587:Arthrometry, Articular D015331:Cohort Studies D005260:Female D005384:Finger Joint D005500:Follow-Up Studies D005542:Forearm D005592:Fracture Fixation D006801:Humans D008297:Male D008875:Middle Aged D015588:Observer Variation D009864:Ontario D011403:Pronation D011446:Prospective Studies D011885:Radius Fractures D016059:Range of Motion, Articular D018570:Risk Assessment D013484:Supination D016896:Treatment Outcome D014954:Wrist Injuries D055815:Young Adult
Measurement Forearm rotation Distal radius fracture Goniometry