Comparison of lower limb sagittal plane kinematics and kinetics between Theia markerless and conventional marker-based double limb squat analysis in patients post ACLr

Authors

Cole Whitelaw, University of Southern CaliforniaFollow
Willa Ma, University of Southern CaliforniaFollow
Jiaqi Wang, University of Southern CaliforniaFollow
Grace Choi
Susan Sigward, University of Southern CaliforniaFollow

Abstract

Markerless motion capture (MoCap) may offer a promising advancement in the assessment of limb kinematics and kinetics, providing enhanced convenience and efficiency for movement assessments compared to traditional marker-based MoCap systems lowering the barrier for access into clinical biomechanics testing. In clinical contexts, particularly when evaluating lower limb kinematics and kinetics in populations with conditions like anterior cruciate ligament reconstruction (ACLr), it is crucial for a system to accurately detect subtle changes in movement indicative of injury or pathology. PURPOSE: Determine concurrent validity of kinematic and kinetic data collected using marker and markerless MoCap technologies during a double limb squat in patients post-ACLr. METHODS: Kinematic data were collected concurrently with 12 infrared (marker) and 8 video cameras along with ground reaction forces while 10 individuals (122.3 ± 21.75 days) post-ACLr performed bilateral squats. Kinematic models created from pose estimations based off maker (Qualisys) and video data (Theia) were used to calculate peak hip, knee and ankle sagittal plane angles and moments for right (R) and left (L) limbs. Three trials were used to examine the relationship (linear regression, R²) and agreement (ICC 2,2) between methods. Absolute agreement and limits of agreement (LOA) were calculated. RESULTS: ICC and R² values for knee and ankle kinematic and kinetic variables were > 0.93, >.9 and >.75, 0.65-0.79 for hip variables. For knee flexion, LOA ranges were 13(L) and 16.6(R) degrees; and 0.15(L) and 0.18(R) Nm/kg for knee extensor moments. CONCLUSION: These data indicate excellent relationships and agreement between knee and ankle variable calculations made with each system but only good agreement for hip variables. This shows promise for application in clinical biomechanics testing of knee function post-ACLr. The range of the LOA in knee variables may suggest the magnitude of disagreement may be larger than the expected deficits. Consideration of between limb deficits is needed before drawing further conclusions.

Recommended Citation

Whitelaw, Cole; Ma, Willa; Wang, Jiaqi; Choi, Grace; and Sigward, Susan (2024) "Comparison of lower limb sagittal plane kinematics and kinetics between Theia markerless and conventional marker-based double limb squat analysis in patients post ACLr," International Journal of Exercise Science: Conference Proceedings: Vol. 14: Iss. 4, Article 173.
Available at: https://digitalcommons.wku.edu/ijesab/vol14/iss4/173