The Mechanics of Arm Swing in Human Running

Open Access
Brough, Lydia Gail
Area of Honors:
Mechanical Engineering
Bachelor of Science
Document Type:
Thesis Supervisors:
  • John Henry Challis, Thesis Supervisor
  • Zoubeida Ounaies, Honors Advisor
  • running
  • biomechanics
  • arms
The purpose of this study is to better understand the mechanics of upper extremity function and variation in running. Two groups of four subjects, one with comparably high arm carry and the other with low arm carry as determined by their average elbow flexion angles (96.2°, 90.9°, 107.5°, and 92.8° versus 71.2°, 64.0°, 67.8°, and 79.7°) were selected from a group of 80 healthy runners. Inverse kinematic models were built for each runner using motion capture and force plate data. Model-based shoulder and elbow joint moments, arm segment power, relative phase, symmetry, and induced acceleration were calculated and compared between the two sets of participants. The study found that subjects with higher arm carry had significantly lower shoulder moments and higher elbow moments about the flexion axes. The high arm carry group also had much higher induced acceleration indices for the shoulder and elbow joints. However, there were no significant differences in symmetry or relative phase of the elbow and shoulder joint moments, angular momentum of the arms about the vertical axis through the model center of mass, arm segment power, arm segment power, or angular momentum about the vertical axis. Because there is very limited research about arm swing variation in running, these results will provide a baseline for future studies.