Computational biomechanics of human knee joint in stair ascent: Muscle‐ligament‐contact forces and comparison with level walking

Abstract

About a third of knee joint disorders originate from the patellofemoral (PF) site that makes stair ascent a difficult activity for patients. A detailed finite element model of the knee joint is coupled to a lower extremity musculoskeletal model to simulate the stance phase of stair ascent. It is driven by the mean of measurements on the hip-knee-ankle moments-angles as well as ground reaction forces reported in healthy individuals. Predicted muscle activities compare well to the recorded electromyography data. Peak forces in quadriceps (3.87 BW, body weight, at 20% instance in our 607 N subject), medial hamstrings (0.77 BW at 20%), and gastrocnemii (1.21 BW at 80%) are estimated. Due to much greater flexion angles-moments in the first half of stance, large PF contact forces (peak of 3.1 BW at 20% stance) and stresses (peak of 4.83 MPa at 20% stance) are estimated that exceed their peaks in level walking by fourfold and twofold, respectively. Compared with level walking, ACL forces diminish in the first half of stance but substantially increase later in the second half (peak of 0.76 BW at 75% stance). Under nearly similar contact forces at 20% of stance, the contact stress on the tibiofemoral (TF) medial plateau reaches a peak (9.68 MPa) twice that on the PF joint suggesting the vulnerability of both joints. Compared with walking, stair ascent increases peak ACL force and both peak TF and PF contact stresses. Reductions in the knee flexion moment and/or angle appear as a viable strategy to mitigate internal loads and pain.

Development and validation of a subject-specific integrated finite element musculoskeletal model of human trunk with ergonomic and clinical applications

“…Such realistic simulation of passive-active coupling is possible only when both components are accurately represented alongside in a model study. The coupled model of the lower extremity for the knee (Makani et al, 2022; Sharifi and Shirazi-Adl, 2021) and hip (Hua et al, 2022) attest to this point.…”

The Effects of Long-Term Walking Exercise on Structural Progression, Symptoms, and Extensor Muscle Strength in Patients with Mild or at High Risk of Knee Osteoarthritis: Data from the Osteoarthritis Initiative

“…6,27 Importantly, the increased knee EMS not only signifies a localized impact on muscular performance but also may have an impact on overall joint stability and functionality. 28 Strengthened knee extensor muscles could contribute to enhanced joint support and a reduction in mechanical stress on the affected knee joint, 20,22 potentially translating into improved activity levels and symptom relief for individuals with mild knee OA. 27 Notably, in this study, we also found a significant decrease in knee EMS in female nonwalkers and male nonwalkers at 24 mos compared with baseline.…”

“…This may potentially exacerbate the loss of medial knee cartilage and worsening of medial bone marrow lesions 18,19 . Nevertheless, studies have also highlighted the positive effects of strengthening extensor muscles, particularly the quadriceps, which could minimize the adverse consequences of HKA angle abnormalities 20,21 . By increasing EMS, the increased medial knee contact force caused by the increased HKA angle could be reduced, 20 thereby improving the medial JSN.…”

“…Nevertheless, studies have also highlighted the positive effects of strengthening extensor muscles, particularly the quadriceps, which could minimize the adverse consequences of HKA angle abnormalities 20,21 . By increasing EMS, the increased medial knee contact force caused by the increased HKA angle could be reduced, 20 thereby improving the medial JSN. Furthermore, research has found that increasing hip adduction moment may effectively help prevent the progression of mild to moderate medial knee OA 22 .…”