Thesis Format
Monograph
Degree
Master of Science
Program
Kinesiology
Supervisor
Pamukoff, Derek N.
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.
Summary for Lay Audience
Marker based motion capture is a way of measuring joint motion and requires placing markers on a person’s body. These markers are used to outline a skeleton and for cameras to track their movement. However, there may be errors in marker placement or marker motion that contribute to errors in the creation of a skeletal model. Moreover, sex and body size also contribute to variability in measurement. However, ML motion capture does not need markers, which may remove human error, but it is unknown if sex and body size will affect the software’s ability to measure joint angles. This study examined how sex, body size, and motion capture method affects the ability to record similar joint angles between days and compared joint angles within a session between systems when walking, jumping, and rising from a chair. Results show that ML is better at recording similar joint angles between days than MB, but it is more difficult during jumping and rising from a chair because of greater hip motion. Measurements within a session show that ML is affected by sex and body size at the hip and knee. However, differences between methods are more prevalent during movements with greater hip motion (jumping and rising from a chair). Therefore, future studies should consider sex, body size, and movements characteristics when choosing between using MB or ML.
Recommended Citation
Wills, Neil, "The Influence of Motion Capture Method, Sex, and Body Mass Index on Lower Extremity Kinematics" (2024). Electronic Thesis and Dissertation Repository. 10214.
https://ir.lib.uwo.ca/etd/10214
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