Effect of Inhibitory Kinesio-tape of the Upper Trapezius on Lower Trapezius Muscle Excitation

Shoulder pain increases excitation (or activity) of the upper trapezius (UT) and reduces excitation in lower trapezius (LT). Despite inconclusive evidence, kinesio-tape (KT) is often used to modify muscular excitation within the UT and/or LT to help correct alterations in scapular position and motion associated with shoulder pain/injury. The objectives of the current study were to determine if: 1) inhibitory KT to the UT acutely increases muscle excitation (whole-muscle and spatial distribution) within the LT in healthy individuals; and 2) if loading the limb alters the magnitude of change in muscle excitation of the LT. We hypothesize that: 1) inhibitory KT application to the UT will immediately increase whole-muscle LT excitation, and result in an inferior shift in the distribution of excitation within the LT compared to no tape and sham-KT tape conditions; and 2) the magnitude of immediate increase in LT excitation with KT would be greater in the loaded condition. A repeated-measures, crossover design was used to determine the impact of KT applied to UT and load on muscle excitation of the LT. Participants were asked to perform a repeated arm elevation task during three different taping conditions: no KT, experimental KT and sham KT. Each taping condition performed the repeated arm elevation task during two loading conditions: no load and loaded with 2.3 kilograms. All six conditions were tested during one visit with the no load condition preceding the loaded condition for each taping condition. A baseline trial (no KT; N-KT) was performed first, followed by both an experimental-KT (E-KT) and sham-KT (S-KT) condition. The order of the E-KT and S-KT conditions were randomized and the order was counterbalanced. Testing for each tape condition lasted approximately 10-minutes for a total of 45-minutes per participant including screening, EMG set-up and clean-up. KT was applied to the UT and muscle excitation (EMG amplitude) was measured in the LT using one single 32-grid high-density surface electromyography (HD-sEMG) electrode during a repeated arm elevation task.