Variation in shoulder position sense at mid and extreme range of motion

Objective: To determine the effect of different joint positions on position sense of asymptomatic shoulders. Design: Repeated-measures design. Setting: Laboratory in an educational institution. Participants: Thirty-four asymptomatic, right-handed men. Interventions: The ability of subjects to replicate 3 criterion positions w as examined on subjects' right shoulders by using an isokinetic dynamometer . Three criterion positions were the 50th, 75th, and 90th percentiles of ea ch individual's total passive shoulder rotation range measured from the ful l internal rotation position. Main Outcome Measure: Repositioning accuracy, indicating the difference in degrees between the criterion and matching positions. Results: All subjects were able to reproduce the criterion position near th e end of external rotation range more accurately and consistently than in t he middle range of motion (ROM). Conclusions: Position sense acuity at the shoulder complex varied across th e ROM and may be enhanced near the end of rotation range where there is mor e tension on the restraints to movement. Therefore, an individual's ROM sho uld be factored into any attempt to assess or rehabilitate shoulder proprio ception.