Scapula-Focused Exercises With or Without Biofeedback and Corticospinal Excitability in Recreational Overhead Athletes With Shoulder Impingement

Abstract

Context: Individuals with shoulder impingement syndrome (SIS) exhibit changes in corticospinal excitability, scapular kinematics, and scapular muscle-activation patterns. To restore the scapular kinematics and muscle-activation patterns in individuals with SIS, treatment protocols usually include scapula-focused exercises, such as scapular-orientation and strength training. Objective: To investigate whether scapular-orientation and strength training can reverse the altered corticospinal excitability of recreational overhead athletes with SIS. Design: Randomized controlled clinical trial. Setting: University laboratory. Patients or Other Participants: Forty-one recreational overhead athletes with SIS: 20 in the scapular-orientation group (age ¼ 26.45 6 4.13 years, height ¼ 171.85 6 7.88 cm, mass ¼ 66.70 6 10.68 kg) and 21 in the strengthening group (age ¼ 26.43 6 5.55 years, height ¼ 171.62 6 5.87 cm, mass ¼ 68.67 6 10.18 kg). Intervention(s): Both groups performed a 30-minute training protocol consisting of 3 exercises to strengthen the lower trapezius (LT) and serratus anterior muscles without overactivating the upper trapezius muscles. Participants in the scapular-orientation group were instructed to consciously activate their scapular muscles with electromyographic biofeedback and cues, whereas the strengthening group did not receive biofeedback or cues for scapular motion. Main Outcome Measure(s): Corticospinal excitability was assessed using transcranial magnetic stimulation. Scapular kinematics and muscle activation during arm elevation were also measured. Results: After training, both groups demonstrated an increase in motor-evoked potentials in the LT (P ¼ .004) and increases in scapular upward rotation (P ¼ .03), LT activation (P, .001), and serratus anterior activation (P, .001) during arm elevation. Moreover, the scapular-orientation group showed higher LT activation levels during arm elevation after training than the strengthening group (P ¼ .03). Conclusions: With or without biofeedback and cues, scapula-focused exercises improved scapular control and increased corticospinal excitability. Adding biofeedback and cues for scapular control during exercise helped facilitate greater LT activation, so feedback and cues are recommended during scapula-focused training.