The Influence of Motion Capture Method, Sex, and Body Mass Index on Lower Extremity Kinematics
Abstract
Marker placement and motion artifact induce error in kinematics when using marker-based motion capture (MB). Anatomical differences between sexes and body size may exacerbate error. Marker-less motion capture (ML) may provide an alternative method. However, the effects of sex and body size on ML are unknown. This study examined (1) the effects of sex and body size on MB and ML intersession reliability and (2) the influence of sex, body size, and method on lower body kinematics during gait, sit-to-stand (STS), and a drop-vertical jump (DVJ). ML reliability was greater than MB across all joints and tasks but was lower in tasks with greater hip flexion. Interaction effects at the hip and knee during the DVJ and STS indicate ML may be uniquely affected by participant characteristics during tasks with high hip flexion. Therefore, task selection and participant characteristics should be considered when interpreting data from different motion capture methods.