Quantitative Analysis of Proximal and Distal Kinetic Chain Musculature During Dynamic Exercises.

Oliver, GD, Washington, JK, Barfield, JW, Gascon, SS, and Gilmer, G. Quantitative analysis of proximal and distal kinetic chain musculature during dynamic exercises. J Strength Cond Res 32(6): 1545-1553, 2018-Proximal to distal sequencing for the dynamic movement of throwing is dependent on the movement and stability of the lumbopelvic-hip complex (LPHC) and scapula. Although the need for proximal stability for distal mobility has been vastly documented, pre-throwing programs tend to focus on the traditional rotator cuff activation exercises before long toss. Thus, it was the purpose of this study to describe muscle activations of LPHC stabilizing musculature (bilateral gluteus medius and maximus) and scapular stabilizing musculature (dominant side latissimus dorsi, lower trapezius, upper trapezius, and serratus anterior) during 5 kinetic chain exercises that could be implemented in a throwing program. It was hypothesized that both the LPHC and the scapular stabilizing musculature would exhibit moderate to high activation during all the selected kinetic chain exercises. Nineteen healthy college students (23.2 ± 7.2 years; 176.7 ± 17.9 cm; 78.0 ± 28.6 kg) participated. Surface electromyography was used to measure muscle activity in the LPHC and scapular stabilizing musculature during 5 kinetic chain exercises. A nonparametric Friedman test revealed significantly different muscle activations as a factor of exercise for each muscle, χ(18) = 417.220, p < 0.001. The 5 kinetic chain exercises successfully elicited moderate to high muscle activation in all musculature, except the upper trapezius. Because greater muscle activation of the LPHC and scapular stabilizers are crucial during a throwing task, these exercises are recommended for pre-throwing program implementation because they efficiently prepare the stabilizing musculature for lengthy or strenuous throwing tasks, resulting in a potential decrease in injury susceptibility.