Comparison of Forearm Rotation Allowed by Different Types of Upper Extremity Immobilization

Background: The purpose of this study was to compare the active forearm pronation and supination allowed by a short arm splint, short arm cast, sugar tong splint, long arm splint, and long arm cast in normal, healthy subjects. Methods: Forty healthy, right-handed volunteers (twenty men and twenty women) with a mean age of thirty-five years (range, twenty-three to sixty-six years) were recruited. Two examiners used a goniometer developed for the study to measure the active forearm supination and pronation in each subject with and without the application of the different types of upper extremity immobilization. Forearm pronation and supination were compared among the immobilization methods and between men and women. The inter-rater reliability of the measurements was evaluated with use of the intraclass correlation coefficient. Results: The long arm cast decreased active forearm rotation to <10% of the value with no immobilization. The short arm cast, sugar tong splint, and long arm splint decreased active forearm rotation to <40% of the baseline measurement. No significant difference in active forearm supination or pronation was observed among the short arm cast, sugar tong splint, and long arm splint in the overall study cohort or in the men. However, forearm supination and pronation in the women differed significantly between the short arm cast and both the sugar tong splint and the long arm splint. Conclusions: The long arm cast provided the greatest restriction of forearm rotation. Overall, no significant difference in active forearm supination or pronation was observed among the short arm cast, sugar tong splint, and long arm splint.