Knee extension moment arm variations relate to mechanical function in walking and running

Abstract

The patellofemoral joint plays a crucial mechanical role during walking and running. It increases the knee extensor mechanism's moment arm and reduces the knee extension muscle forces required to generate the extension moment that supports body weight, prevents knee buckling and propels the centre of mass. However, the mechanical implications of moment arm variation caused by patellofemoral and tibiofemoral motion remain unclear. We used a data-driven musculoskeletal model with a 12-degree-of-freedom knee to simulate the knee extension moment arm during walking and running. Using a geometric method to calculate the moment arm, we found smaller moment arms during running than during walking in the swing phase. Overall, knee flexion causes differences between running and walking moment arms as increased flexion causes a posterior shift in the tibiofemoral rotation axis and patella articulation with the distal femur. Moment arms were also affected by knee motion direction and best predicted by separating by direction instead of across the entire gait cycle. Furthermore, we found high inter-subject variation in the moment arm that was largely explained by out-of-plane motion. Our results are consistent with the concept that shorter moment arms increase the effective mechanical advantage of the knee and may contribute to increased running velocity.

A dynamic nomogram for predicting knee osteoarthritis after sports injury based on MR imaging features, demographics and clinical sport-related factors in cold regions of northern China

“…Studies have shown that during the running cycle, the tibia is impacted, and the knee exion angle increases at the moment of foot strike and during the off-ground phase of each run. When muscles are subjected to prolonged repetitive loading, the strength of the hamstrings and quadriceps decreases, leading to increased tibial inversion rotation, femoral translation, and increased risk of KOA [30][31][32] . Another important cause of KOA may be changes in knee cartilage caused by prolonged loading.…”

Morphology and transverse alignment of the patella have no effect on knee gait characteristics in healthy Chinese adults over the age of 40 years

“…The patella functions as an articulating fulcrum, enhancing the moment arm of the extensor mechanism. Additionally, it enhances quadriceps muscle efficiency by elevating the extensor mechanisms away from the axis of rotation of the knee, thus increasing torque ( Wheatley et al, 2021 ). Moreover, it assists in reducing frictional wear that could otherwise damage the extensor mechanism tendon.…”

A Guide to Inverse Kinematic Marker-Guided Rotoscoping Using IK Solvers

“…X-ray Reconstruction of Moving Morphology (XROMM) has permitted biologists and biomechanists to visualize and measure in vivo musculoskeletal movement and ex vivo capacities of an organism with precision and accuracy (e.g., Brainerd et al 2010 ; Gatesy et al 2010 ; Nyakatura and Fischer 2010 ; Stefen et al 2011 ; Baier and Gatesy, 2013 ; Arnold et al 2014 ; Kambic et al 2014 ; Nyakatura et al 2014 ; Camp et al 2015 ; Brainerd et al 2016 ; Panagiotopoulou et al 2016 ; Brocklehurst et al 2017 ; Kambic et al 2017 ; Fischer et al 2018 ; Capano et al 2019 ; Bhullar et al 2019 ; Nyakatura et al 2019 ; van Meer et al 2019 ; Manafzadeh 2020 ; Tsai et al 2020 ; Turner et al 2020 ; Bishop et al 2021a ; Jones et al 2021 ; Manafzadeh and Gatesy 2021 ; Manafzadeh et al 2021 ; Wiseman et al 2021 ; Turner and Gatesy 2021 ; Wheatley et al 2021 ; Regnault et al 2021 ). XROMM captures movement data using biplanar X-ray videos, which is then integrated with 3D scan data consisting of skeletal elements of the same specimen.…”

“…The method (scientific rotoscoping versus IK solvers) should reflect the research goals. For example, biomechanical studies using musculoskeletal models to investigate parameters such as joint moments, moment arms, and/or muscular mechanics typically only include three DOFs at the most proximal joint, with all distal joints typically composed of a single DOF; just flexion–extension (see: Delp et al 1990 ; Seth et al 2016 ; Wiseman et al 2021 ; Bishop et al 2021a , 2021b ; but also see: Kambic et al 2014 ; Wheatley et al 2021 ). This is in contrast to other studies investigating range of motion around a given joint whereby all six DOFs are preferential (i.e., Manafzadeh and Gatesy 2021 ) and are incorporated into scientific rotoscoping approaches, but not in IK solver approaches.…”