A Case Study in Upper Body Kinematics of an Elite Axe Thrower Using Sensor Technology

Abstract

Introduction: This field-based case study assessed linear accelerations of the scapula and elbow in an elite axe thrower in three different axe throwing techniques using two wearable sensors. Methods: One elite axe thrower (35 years; height 181 cm; weight 92 kg) participated in this case study. One wearable sensor (an accelerometer) was located on the dorsal surface of the upper thorax between the medial borders of the scapula. An additional sensor was located on the medial epicondyle of the right elbow to capture linear acceleration magnitudes. The participant performed three different throwing techniques, namely a one hand underarm throw, a two-handed overhead throw, and a one hand overarm throw for a total of four repetitions. Results: Significant differences in scapula acceleration magnitudes were detected in the three throwing techniques analyzed along with significant differences in all acceleration channels (p < 0.001). In contrast, no significant differences in triaxial acceleration magnitude were observed in the elbow in all throwing techniques (p > 0.50). Conclusions: Magnitudes of scapular acceleration varied significantly depending on the type of throw. In contrast, acceleration magnitudes at the elbow displayed high variability despite a non-significant outcome. A wearable sensor could be a valuable tool to enhance throwing performance.