The effects of scapular taping on the surface electromyographic signal amplitude of shoulder girdle muscles during upper extremity elevation in individuals with suspected shoulder impingement syndrome

STUDY DESIGN: Multifactorial, repeated-measures. within-subjects design. OBJECTIVES: To investigate the immediate effects of scapular taping on surface electromyographic (EMG) signal amplitude of shoulder girdle muscles during upper extremity elevation in individuals with suspected shoulder impingement syndrome. BACKGROUND: Individuals with shoulder impingement syndrome may present with increased activity of the upper trapezius and inhibition of other shoulder muscles active during upper extremity elevation. Scapular taping is theorized to normalize shoulder girdle function during scapular upward rotation by decreasing upper trapezius activity and increasing the activity of the lower trapezius and other muscles. METHODS AND MEASURES: Twenty-one volunteers with suspected shoulder impingement syndrome performed shoulder abduction in the scapular plane and a functional overhead-reaching ("shelf") task, both with and without tape. Surface electrodes were applied over the upper trapezius, lower trapezius, serratus anterior, and infraspinatus muscles. Mean root-mean-square of the EMG signal, normalized to maximum contraction, was assessed for each muscle. RESULTS: Upper trapezius activity was significantly lower with tape during shelf task elevation (P = .002), especially above 90 degrees (P <.002). Lower trapezius activity was significantly higher with tape (P = .043). No significant differences were found between the tape and no tape for other muscles for the shelf task. During shoulder abduction in the scapular plane, the main effect for upper trapezius showed a significant decrease of EMG signal amplitude (P = .047) for tape versus no tape, but no significant interactions were found among components of this activity, or for other muscles. CONCLUSION: Scapular taping decreased upper trapezius and increased lower trapezius activity in people with suspected shoulder impingement during a functional overhead-reaching task, and decreased upper trapezius activity during shoulder abduction in the scapular plane. Taping did not affect the other muscles under the loads tested, but it is possible that the activity of these muscles was not deficient at the time of testing.