Analysis of the Muscular Activity of Anticipation of the Deltoid in a Fall Reception Movement: Pilot Study

Anticipation is one of the mechanisms to limit the risk of injury upon receipt of a fall by reducing impact forces. In this anticipation, the Deltoid muscle in particular plays an important role, but its activity has not been studied in this context. The purpose of this study is to investigate the anticipatory activity of the three Deltoid heads in a falling recovery movement, the hypotheses tested are that there is a correlation between the Deltoid anticipatory activity and the impact forces, and that bilateral differences between the studied parameters exist. 4 subjects performed a forward fall simulation, from which the impact forces and muscle activity of the Deltoid heads were measured with electromyography. This study shows that the anticipation activity of the anterior Deltoid is positively correlated to the impact forces, this correlation is not found on the anticipation of the other two heads, on the other hand there is an increased impact force associated with an early impact time on the left side, in accordance with the international literature. The results suggest that Deltoid plays a major role in falls anticipation and reception, and features an asymmetric motor pattern with a first contact of the non-dominant limb to improve the damping phase.