Abstract

The field hockey hit is one of the most important skills used in the game. However, due to the paucity of empirical research, little is known about the biomechanics of this movement. Muscular activation patterns have been shown to be major contributing factors to performance variables in similar swinging motions in golf, tennis and baseball but debate remains about which muscles are contributing to and controlling such motions. Moreover, muscle studies have typically neglected the contribution to movement from segmental interactions and have not related muscle activity to the three-dimensional kinematics of the swing.

The aim of this study was to investigate the contributions from muscular activity and from segmental interactions to the hits of ten male, university-level field hockey players. The activity of sixteen upper body and trunk muscles was monitored using surface electromyography alongside synchronized three-dimensional kinematics of the upper body and hockey stick motions.

Surface electromyographic signals were recorded at 2000Hz bilaterally from the biceps brachii, triceps brachii, the anterior and posterior deltoids, the upper trapezius, the latissimus dorsi and the sternal and clavicular pectoralis major muscles. Three-dimensional kinematic data were collected at 240Hz and each hockey hit was broken down into four phases of the backswing, the early forward swing, acceleration and the early follow-through. These kinematic and electromyographic data were then synchronised and temporally normalised before the electromyographic data were normalised to relative maximal reference contractions.

Right anterior deltoid, right pectoralis major and bilateral latissimus dorsi activity initiates the downswing of the hockey hit, causing the early acceleration of the arms. Segmental interactions, due to these accelerations, cause the hockey stick to lag and the wrists to ‘cock’. A combination of left anterior deltoid, left latissimus dorsi and bilateral pectoralis major activity continue to accelerate the shoulders during the downswing whilst elbow musculature appears to control the effects of segmental interactions. These segmental interactions then become involved in wrist ‘uncocking’ as the stick accelerates towards impact with the ball.

The effects of muscular activity and segmental interactions cause the right elbow to flex then extend, whereas the left elbow demonstrates a more constant degree of extension throughout the hit. Both wrists display the same pattern of ‘cocking’ then ‘uncocking’. These combined patterns lead the left arm and stick system to function as a double pendulum whilst the right arm and stick more closely resemble a triple pendulum.