We investigated muscle activities of the scapular muscles during low row procedure (LR) usually used 12 weeks after a rotator cuff repair, and evaluated its effective application period comparing with scapular retraction procedure (SR) used for early postoperative period. Twelve healthy adults (mean age, 26.8 years) were enrolled in the current study. %MVICs (maximal voluntary isometric muscle contractions) of middle trapezius, lower trapezius, serratus anterior, posterior deltoid, and infraspinatus were calculated from the surface electromyography during both LR and SR. The %MVIC of either the middle trapezius or lower trapezius was not significantly different between during the LR and the SR. The %MVIC of the serratus anterior, posterior deltoid and infraspinatus during the LR was significantly higher than those during the SR (p=0.018, p<0.001, p<0.001, respectively). Additionally, the %MVIC of the posterior deltoid and infraspinatus in the SR was less than 20%. In training phase after rotator cuff repair, LR was considered to be effective procedure for most of the scapular muscles 12 weeks after a surgical repair of the rotator cuff. However, LR earlier than 12 weeks after the surgery is considered to yield a risk of re-tear of the rotator cuff, and SR may be a preferred training procedure in this early phase.
