1. Impact of Surface Stability and Hand Separation on Activation of Agonist and Stabilizing Muscles During Push-Up Exercise

Abstract

Stability is an important factor to consider when designing an exercise program as recent studies have suggested that there can be benefits to performing exercises on unstable surfaces compared to rigid ones. Furthermore, to increase strength of the agonist muscles, pectoralis major and triceps brachii, various hand positions can also be implemented to increase stress on these muscles during an exercise. Thus, our goal was to test the impact that surface stability and hand position can have on muscle activity of stabilizing and agonist muscles during a push-up exercise. Surface electrodes were attached to specific stabilizing and agonist muscles and electromyography (EMG) data was used to measure muscle activity. When compared to a rigid surface, a push up exercise performed on an unstable surface of a BOSU ball resulted in higher muscle activity for all the stabilizing muscles, while only the pectoralis major had an increase in activity for the agonist muscle group. In regards to hand position, a narrow hand spacing resulted in greater activation of all the stabilizing muscles and was able to specifically target the triceps brachii, while the use of wide hand spacing only isolated the pectoralis major. Hence an exercise program consisting of push-ups can target the stabilizing muscles further by using an unstable surface and a narrow hand position. In regards to the agonist muscles, the use of a specific surface and hand position can allow the user to target the agonist muscle they desire in a more efficient manner.