REFLEX MUSCLE-CONTRACTION IN ANTERIOR SHOULDER INSTABILITY

Reduced proprioception may contribute to recurrent anterior shoulder i nstability. Twelve patients with unilateral shoulder instability were investigated for evidence of deficient proprioception with an activate d pneumatic cylinder and surface electromyography electrodes; the cont ralateral normal shoulder was used as a control. The latency between o nset of movement and the detection of muscle contraction was used as a n index of proprioception. No significant difference in muscle contrac tion latency was detected between the stable and unstable shoulders, s uggesting that there was no significant defect in muscular reflex acti vity. This study does not support the use of proprioception-enhancing physiotherapy in the treatment of posttraumatic anterior shoulder inst ability.