Impaired Joint Proprioception at Higher Shoulder Elevations in Chronic Rotator Cuff Pathology

Abstract

Anderson VB, Wee E. Impaired joint proprioception at higher shoulder elevations in chronic rotator cuff pathology. Objectives To assess the degree of impairment of shoulder proprioceptive acuity in individuals with chronic rotator cuff pathology (CRCP), and to examine the effect of impingement-related shoulder pain on acuity using a reliable laboratory technique. Design Case-control study. Setting University human movement laboratory. Participants A volunteer sample of individuals with CRCP (n=26) were recruited and screened, and compared with age-, sex-, and limb dominance–matched individuals (n=30) who acted as controls. Ten participants with CRCP underwent repeat assessment after 2 days to determine the intrarater reliability of proprioceptive measurement. Interventions Not applicable. Main Outcome Measures Each participant underwent assessment of joint position sense at 40° and 100° of scapular plane abduction using an active position-matching task. Movements were recorded with reflective skin markers and a multidimensional motion analysis system. Self-reported pain intensity associated with the procedure was recorded with a visual analog scale. Results Intraclass correlation coefficients (model 3,5) between repeat assessments ranged from .54 to .99. On average, those with CRCP demonstrated reduced acuity at 40° and 100° test angles. In comparison with the control group, proprioceptive acuity was significantly impaired ( P<.01) at the 100° test angle, where the pain intensity was significantly greater ( P<.01). Conclusions This study demonstrated impairment of shoulder joint position sense in CRCP. The degree of proprioceptive impairment was greatest at higher elevations in the setting of increased shoulder impingement and pain, which may serve to perpetuate the pathology. These findings provide a theoretic rationale for the continued implementation of proprioceptive rehabilitation programs in managing CRCP.