Grant Ford, M ^*†, Barbe, M, F ^†, Barr, A E ^†, Kozin, S ^‡, Sitler, M ^†,Kendrick, Z^† : *Montclair State University, †Temple University,‡Shriner’s Children’s Hospital of Philadelphia

The wrist pain associated with repetitive dorsiflexion and compression is pervasive among male gymnasts, particularly during pommel horse exercises. No research has been reported to date to determine the biomechanical effects of gymnastic wrist orthoses. The purpose of this study was to assess the biomechanical effects of the Ezy® ProBrace prophylactic wrist orthosis on the wrist and ulnocarpal joints during mechanical loading in a cadaveric model. Eleven fixed cadaveric forearm-wrist specimens (6 males, 5 females) were subjected to a 71.4 lb compressive load applied through the long axis of the pronated forearm with the wrist in dorsiflexion and the palm in contact with a support surface. The independent variables were orthotic condition (Ezy® ProBrace with palmar pad, the Ezy® ProBrace without palmar pad, and a non-orthotic control), ulnar variance (positive ulnar variance and neutral ulnar variance) and sex. The dependent variables were wrist joint dorsiflexion angle (measured with a hand-held goniometer) and ulnocarpal joint intracompartment peak pressure (measured with a Stryker® Intracompartmental Pressure Monitor). Statistical analysis, which consisted of a 3 X 2 X 2 MANOVA with repeated measures on the orthotic condition, revealed significant ( p < .05 ) main effects for orthotic condition and sex only. Post hoc analyses were conducted to determine where the differences existed. Wrist joint dorsiflexion angle was significantly lower for the Ezy® ProBrace with palmar pad (80.72 deg ± 5.9) and without the palmar pad (82.73 deg ± 5.0) than for the non-orthotic control (87.52 deg ± 4.1). Ulnocarpal joint intracompartmental peak pressure was significantly lower for the Ezy® ProBrace with palmar pad (110.5 mm Hg ± 13.5) than for the Ezy® ProBrace without palmar pad (142.0 mm Hg ± 19.3). Ulnocarpal joint intracompartmental peak pressure was also significantly lower for the Ezy® ProBrace with palmar pad than for the non-orthotic control (161.7 mm Hg ± 18.3). Ulnocarpal joint intracompartmental peak pressure was higher for female specimens (148.08 mm Hg ± 26.6) than for male specimens (129.67 mm Hg ± 25.05). Within the limitations of the cadaveric model and the test protocol used in this study, wrist joint dorsiflexion angle was reduced by the Ezy® ProBrace with and without the palmar pad. However, ulnocarpal joint intracompartmental peak pressure was reduced by the Ezy® ProBrace with palmar pad only. From a clinical perspective, prevention of pathological gymnastic wrist changes requires intervention in pressure attenuation. The Ezy® ProBrace with palmar pad was beneficial in pressure attenuation. Use of this orthosis during pommel horse training in gymnasts may provide prophylactic benefit by decreasing the cumulative consequences of the repetitive stress of pommel horse exercise training.

This research was partially supported by Stryker® Instruments (Kalamazoo, MI).