Marker location and knee joint model constraint affect the reporting of overhead squat kinematics in elite youth football players

Coyne, Lara M.; Newell, Miche�l; Hoozemans, Marco J. M.; Morrison, Andrew; Brown, Susan J.

Abstract

Motion capture systems are used in the analysis and interpretation of athlete movement patterns for a variety of reasons, but data integrity remains critical regardless of the purpose of measurement. The extent to which marker location or constraining degrees of freedom in the biomechanical model impacts on this integrity lacks consensus. Elite youth academy footballers (n=10) performed repeated bilateral overhead squats using a marker-based motion capture system. Kinematic data were calculated using four different marker sets with three degrees of freedom (3DOF) and six degrees of freedom (6DOF) configurations for the three joint rotations of the right knee. Root mean squared error (RMSE) differences between marker sets ranged in the sagittal plane between 1.02 and 4.19 degrees to larger values in the frontal (1.30- 6.39 degrees) and transverse planes (1.33 and 7.97 degrees). The cross-correlation function (CCF) of the knee kinematic time series for all eight marker-sets ranged from excellent for sagittal plane motion (>0.99) but reduced for both coronal and transverse planes (< 0.9). Two-way ANOVA repeated measures for marker sets calculated for all directions at peak squat knee flexion revealed significant differences between marker sets for frontal and transverse planes ( < 0.9). Two-way ANOVA repeated measures for marker sets calculated for all directions at peak squat knee flexion revealed significant differences between marker sets for frontal and transverse planes (p < 0.05). Pairwise transverse plane 6DOF marker set comparisons showed significant differences except between the anterior partial cluster and cluster marker sets. The paired 3DOF comparison revealed a significant difference between two of the four marker sets. The 3DOF and 6DOF model comparisons demonstrated significant differences except for the anterior partial cluster. Marker location and constraining DOF while measuring relatively large ranges of motion in this population are important considerations for data integrity. This was particularly evident in the measurement of frontal and transverse kinematics with implications for future studies using motion capture with athletic populations.

Citation

Coyne, L. M., Newell, M., Hoozemans, M. J. M., Morrison, A., & Brown, S. J. (in press). Marker location and knee joint model constraint affect the reporting of overhead squat kinematics in elite youth football players. Sports Biomechanics, https://doi.org/10.1080/14763141.2021.1890197

• Journal Article Type: Article
• Acceptance Date: Feb 10, 2021
• Online Publication Date: Mar 5, 2021
• Deposit Date: Feb 17, 2021
• Publicly Available Date: Mar 6, 2022
• Journal: Sports Biomechanics
• Print ISSN: 1476-3141
• Electronic ISSN: 1752-6116
• Publisher: Routledge
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1080/14763141.2021.1890197
• Keywords: Marker-based motion capture, marker location, overhead squat, constrained, unconstrained kinematic model, knee kinematics, elite youth football
• Public URL: http://researchrepository.napier.ac.uk/Output/2744167