Comparison of muscle activity and trunk compensation during modified push-up plus exercises in individuals with scapular winging

BACKGROUND: Push-up plus exercise is applied to scapular winging to selectively activate serratus anterior (SA). OBJECTIVES: To compare muscle activity, muscle activity ratios, and the degrees of rotation of the thoracic and lumbar spine during a modified push-up plus exercise. METHODS: In total, 20 subjects with scapular winging participated. Subjects performed the knee push-up plus with ipsilateral leg extension (KPP-ILE) and the standard push-up plus with ipsilateral leg extension (SPP-ILE) exercises. During the SPP-ILE and KPP-ILE, SA, pectoralis major (PM), ipsilateral external oblique (ipsiEO), and contralateral external oblique (contEO) muscle activities, the SA/PM and ipsiEO/contEO ratios were assessed and the degree of rotation of the thoracic and lumbar spine were assessed. RESULTS: Muscle activities of SA, PM, ipsiEO, contEO, and SA/PM ratio were significantly higher during SPP-ILE than KPP-ILE. The ipsiEO/contEO ratio decreased more significantly during SPP-ILE versus KPP-ILE. Thoracic and lumbar rotation values were significantly lower in SPP-ILE. CONCLUSIONS: The SPP-ILE may be a useful exercise for subjects with scapular winging because of the increased SA/PM ratio, the diminished compensatory rotation through increased scapular stabilization muscle activity and co-contraction of the abdominal trunk-stabilizing muscles.