Muscle Activation Levels During Early Postoperative Rehabilitation Exercises in Slap Repaired Patients, a Pilot Study

Background: Few studies have examined muscular activation levels during commonly prescribed range of motion (ROM) exercises in a post-surgical superior labral tear anterior to posterior (SLAP) repair patient group. The present cross-sectional study compared shoulder musculature activation levels between postoperative SLAP repair patients with those of a healthy control cohort performing commonly prescribed postoperative shoulder exercises. The maximal ROM (MAX ROM) achieved during exercises was also studied. Methods: Ten healthy volunteers and nine postoperative patients (post-SLAP) performed 10 rehabilitative exercises during the recording of electromyogram (EMG) activity from six shoulder muscles. Root mean squared amplitudes normalized to a submaximal reference voluntary contraction (RVC) were analyzed to compare exercises. A two-dimensional video of humeral-trunk angle captured the shoulder ROM for each exercise. Results: One significant difference was found between groups; the anterior deltoid mean activity across all exercises was found to be higher in the post-SLAP group 53% RVC [95% confidence interval (CI) = 48% to 57% RVC] compared to the healthy group 46% RVC (95% CI = 42% to 50% RVC) (p = 0.02). Post-SLAP patients generated the least MAX ROM performing the Pendulum exercise 97°(95% CI = 88° to 107°) and the greatest during Forward Bow 131° (95% CI = 121° to 142°), (p = 0.002). Conclusions: The present study identifies the shoulder muscle EMG and MAX ROM obtained during rehabilitation exercise in patients’ after SLAP repair. Knowledge of these parameters will help clinicians match the appropriate exercise to meet the desired objective for the particular rehabilitation goal.