Designing an optimal postoperative loading protocol for our patients with rotator cuff repair might be a challenge. Exercises are important in the early postoperative stages to improve range of motion (ROM) and motor performance of the shoulder, but it is important not to overload the repairing cuff. Exercise prescription could be based on known muscle activity levels elicited during each exercise, as this could be an estimate of stress placed on the rotator cuff tendon.
In 2017, Edwards et al. synthesized the current literature regarding rotator cuff muscle activation during common rehabilitative exercises routinely prescribed after rotator cuff repair. Different from other articles, the paper of Edwards et al. (2017) also included passive and/or active-assisted activities in conjunction with active strengthening exercises, required for therapists to better prescribe exercises throughout the entire postoperative rehabilitation timeline.
An important remark of their study is that their information is based upon EMG studies in asymptomatic shoulders. Therefore, caution should be applied in extrapolating data collected from healthy subjects and applying results strictly in a clinical setting to postoperative patients. After a 2-week period of strict immobilization , they advise a staged introduction of protected, passive ROM to 6 weeks after surgery, followed by restoration of active ROM, and then progressive strengthening beginning at postoperative week 12. In the early stages of rotator cuff repair, exercises with maximum 15% of the maximum voluntary contraction (MVC) are recommended for a safe loading of the cuff. The bulk of passive ROM exercises demonstrated activation levels below the cutoff, and active-assisted exercises using the asymptomatic limb to move the operated limb also generated low-level activation in both the supraspinatus and infraspinatus. However, active-assisted exercises using a bar or a pulley to elevate the operated limb tended to generate over 15% MVIC, suggesting that their use early in rehabilitation may be inappropriate. In phase 2 (after 6 weeks), they recommend active-assisted to active motion phase exercises with EMG activation <= 20% MVC. In the third phase, exercises with EMG activation of supraspinatus and infraspinatus between 21% and 50% MVIC are allowed. At 20 weeks postoperative, the repair site can tolerate greater loads at >50%MVIC. A detailed overview of exercises with their respective muscle activity can be found in their article. A summary of their proposed rehabilitation program can be found in the table below.
Reference: Edwards PK, Ebert JR, Littlewood C, Ackland T, Wang A. A Systematic Review of Electromyography Studies in Normal Shoulders to Inform Postoperative Rehabilitation Following Rotator Cuff Repair. J Orthop Sports Phys Ther. 2017 Dec;47(12):931-944.
Author: Birgit Castelein