Motion Analysis and Inverse Dynamics of Knee Joint Biomechanics
We conducted several motion analysis projects to calculate knee joint biomechanics in adult populations whom are at high risk for knee osteoarthritis (OA). The long-term goal of these studies was to identify weight-loss and/or fitness sustainment exercises that can be considered “safe” in the context of preventing, or slowing the progression of, OA.
Markers are placed on participants and a motion analysis system with digital cameras and Cortex software is used to record data during exercises. To date, the exercises we have studied include gait (i.e., walking), cycling, elliptical training, and rowing. Load cells cells are used to measure the external loads that are applied to the paricipant's feet, and that load cell data is used with the marker data to calculate knee loads (i.e., forces and torques) using inverse dynamic analyses. In some studies, EMG sensors are used to record muscle activation levels in the muscles surrounding the knee joint and that data is used in EMG-driven inverse dynamic analyses to calculate muscle and knee joint contact forces.
Currently, we are extending this work by focusing on better understanding the relationships between overweight/obesity, balance biomechanics, and knee joint biomechanics for children. This is a critical aim for our society as overweight children are at high risk of developing early signs of OA - even as early as in their late teens.
Current and former students listed below have worked on projects involving the designated populations that are at high risk for knee OA:
Caitlyn Berryhill, Jake Larson, Ben Presley, Samantha Moberly, Ethan Nikcevich, Sarah Pickering, Kaila Lawson, Marissa Martinez: overweight and obese children
Ally Lai, Hunter Morse, Sam Tucker, Shaida Biglari, Rey Fernandez, Erika Savi, Chiara Marino, Juan Gutierrez-Franco, Luke Kraemer: overweight and obese adults
Greg Orekhov, Elizabeth Heyde, Shaida Biglari, Rey Fernandez, Brad Wash: transtibial (i.e., below knee) amputees
Megan Pottinger, Katherine Mavrommati: ACL reconstructive surgery patients
Journal Papers
- Skaro J, Hazelwood SJ, Klisch SM. Knee angles after crosstalk correction with principal component analysis in gait and cycling. ASME Journal of Biomechanical Engineering, 143(5): 054501 (Feb 22), 2021. https://doi.org/10.1115/1.4049809
- Orekhov G, Robinson AM, Hazelwood SJ, Klisch SM. Knee joint biomechanics in transtibial amputees in gait, cycling, and elliptical training. PLOS One, 14(12): e0226060 2019. https://doi.org/10.1371/journal.pone.0226060
The abstracts for journal papers are presented below.
Knee joint biomechanics in transtibial amputees in gait, cycling, and elliptical training.
Transtibial amputees may experience decreased quality of life due to increased risk of knee joint osteoarthritis (OA). No prior studies have compared knee joint biomechanics for the same group of transtibial amputees in gait, cycling, and elliptical training. Thus, the goal of this study was to identify preferred exercises for transtibial amputees in the context of reducing risk of knee OA. The hypotheses were: 1) knee biomechanics would differ due to participant status (amputee, control), exercise, and leg type (intact, residual) and 2) gait kinematic parameters would differ due to participant status and leg type. Ten unilateral transtibial amputee and ten control participants performed exercises while kinematic and kinetic data were collected. Two-factor repeated measures analysis of variance with post-hoc Tukey tests and non-parametric equivalents were performed to determine significance. Maximum knee compressive force, extension torque, and abduction torque were lowest in cycling and highest in gait regardless of participant type. Amputee maximum knee extension torque was higher in the intact vs. residual knee in gait. Amputee maximum knee flexion angle was higher in the residual vs. intact knee in gait and elliptical. Gait midstance knee flexion angle timing was asymmetrical for amputees and knee angle was lower in the amputee residual vs. control non-dominant knees. The results suggest that cycling, and likely other non-weight bearing exercises, may be preferred exercises for amputees due to significant reductions in biomechanical asymmetries and joint loads. Published as a journal paper (https://doi.org/10.1371/journal.pone.0226060).
Knee angles after crosstalk correction with principal component analysis in gait and cycling.
Principal Component Analysis (PCA) has been used as a post-hoc method for reducing knee crosstalk errors during gait analysis. PCA minimizes correlations between flexion-extension (FE), abduction-adduction (AA), and internal-external rotation (IE) angles. However, previous studies have not considered PCA for exercises involving knee flexion angles that are greater than those typically experienced during gait. Thus, the goal of this study was to investigate using PCA to correct for crosstalk during one exercise (i.e., cycling) that involves relatively high flexion angles. Fifteen participants were tested in gait and cycling using a motion analysis system. Uncorrected FE, AA, and IE angles were compared to those calculated with PCA performed on 1) all angles (FE-AA-IE PCA correction) and 2) only FE-AA angles (FE-AA PCA correction). Significant differences existed between uncorrected and FE-AA-IE PCA corrected AA and IE angles for both exercises, between uncorrected and FE-AA PCA corrected AA angles for both exercises, and between FE-AA-IE and FE-AA PCA corrected IE angles for cycling. Correlations existed before PCA correction and were eliminated following PCA correction with the exception that FE-IE correlations remained following FE-AA PCA correction. Since the two PCA analyses differed only in their IE angle predictions for the high flexion exercise (cycling), IE angle results were compared to previous studies. Using FE-AA PCA correction may be the preferred protocol for cycling as it appeared to retain physiological IE angle correlations at high flexion angles. However, there exists a critical need for studies aimed at obtaining more accurate IE angles in such exercises (https://doi.org/10.1115/1.4049809).