An electromyographic analysis of the cuff link rehabilitation device

Context: Closed kinetic chain exercises are reported to provide a more functional rehabilitation outcome. Objective: To determine the amount of muscle activity in 4 shoulder muscles during exercise on the Cuff Link. Design: Repeated measures. Setting: Laboratory. Subjects: 10 men and 10 women, age 18-50. Intervention: Subjects performed 3 sets of 5 revolutions on the Cuff Link in non-weight-bearing, partial-weight-bearing, and full-weight-bearing positions. Main Outcome Measures: Electromyography data were collected from the upper trapezius, anterior deltoid, serratus anterior, and pectoralis major and were expressed as percentage of maximal isometric contractions. Results: Significant differences were found across the weight-bearing conditions for all 4 muscles. Exercise on the Cuff Link required minimal to significant amounts of muscle recruitment. Conclusions: Muscle recruitment increases as weight bearing increases during use of the Cuff Link, suggesting an increase in dynamic stabilization of the glenohumeral joint.