title: Reflex muscle contraction in anterior shoulder instability.
abstract: Reduced proprioception may contribute to recurrent anterior shoulder instability. Twelve patients with unilateral shoulder instability were investigated for evidence of deficient proprioception with an activated pneumatic cylinder and surface electromyography electrodes; the contralateral normal shoulder was used as a control. The latency between onset of movement and the detection of muscle contraction was used as an index of proprioception. No significant difference in muscle contraction latency was detected between the stable and unstable shoulders, suggesting that there was no significant defect in muscular reflex activity. This study does not support the use proprioception-enhancing physiotherapy in the treatment of posttraumatic anterior shoulder instability.
authors.affiliation: Nuffield Orthopaedic Centre, Headington, Oxford, United Kingdom.
authors.forename: D A
authors.initials: DA
authors.lastname: Wallace
authors.forename: D J
authors.initials: DJ
authors.lastname: Beard
authors.forename: R H
authors.initials: RH
authors.lastname: Gill
authors.forename: B
authors.initials: B
authors.lastname: Eng
authors.forename: A J
authors.initials: AJ
authors.lastname: Carr
mesh_terms: D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000503:physiopathology; D010369:Pectoralis Muscles / Q000503:physiopathology; D011434:Proprioception; D011930:Reaction Time; D012008:Recurrence; D012018:Reflex; D012782:Shoulder; D012783:Shoulder Dislocation / Q000503:physiopathology*