The laser-pointer assisted angle reproduction test for evaluation of proprioceptive shoulder function in patients with instability.

Balke M, Liem D, Dedy N, Thorwesten L, Balke M, Poetzl W, Marquardt B

Zusammenfassung

Over the last decade, proprioceptive function gained increasing attention in joint disorders such as instability of the shoulder. Common tests for evaluation of proprioception are limited by their complexity and high technical demands. Thus, they are hardly applicable during daily routine. Our hypothesis was that the simplified "laser-pointer assisted angle reproduction test" (LP-ART) presented here allows for clinically feasible assessment of proprioceptive shoulder function.Active angle reproduction capability as an aspect of sensorimotor function was evaluated with the new method in patients with shoulder instability (n = 24) and healthy controls (n = 24). 15 patients had traumatic, 9 non-traumatic anterior instability (6 bilateral), 17 were treated surgically, 13 non-operatively. Tests were performed in flexion and abduction in different angles (55°, 90°, 125°) in randomized order.Angle reproduction capability was worst below shoulder level (55°) in all groups. Best results were achieved at shoulder level (90°). Healthy controls showed overall better results than patients with instability. Patients after surgical stabilization had better results in 55° and 90° abduction compared to instability patients before surgery.The new LP-ART presented here is a technically simple, yet effective instrument for evaluation of the proprioceptive function of the shoulder. In contrast to former test setups it is feasible in daily routine. Compared to healthy controls, patients with unstable shoulder joints show significant proprioceptive disorders that can be quantified by the LP-ART.