Biomechanics of Knee Osteoarthritis

Knee osteoarthritis arises from progressive degeneration of the articular cartilage and underlying bone within the tibiofemoral and patellofemoral compartments, driven in large part by altered mechanical loading. Changes in gait patterns, joint alignment and muscle coordination lead to uneven distribution of forces across the joint surfaces, accelerating wear in vulnerable regions. External moments about the knee, especially the adduction moment, serve as surrogate measures of medial compartment loading and correlate with disease onset and progression. Advances in computational modelling, machine learning and wearable sensing have deepened our understanding of how subtle variations in stride, ground reaction forces and neuromuscular co-contraction contribute to cartilage damage. At the tissue scale, overloading disrupts chondrocyte homeostasis and degrades extracellular matrix, while at the organ scale, compensatory gait adaptations aim to minimise pain but may exacerbate mechanical imbalance. Integrating multi-scale data—from joint kinematics to cartilage morphology—offers new avenues for targeted interventions, personalised mobility retraining and real-time feedback to restore more favourable loading patterns and slow disease progression.

Research from Nature Portfolio

A foundational three-dimensional gait analysis study established clear links between radiographic severity, as graded by a standard four-level system, and specific kinematic alterations. Individuals with higher severity demonstrated reduced flexion range, increased adduction angles and altered femoral translation at key gait phases. These systematic changes in joint motion not only reflect compensatory strategies but also highlight mechanical thresholds beyond which cartilage deterioration accelerates. The work provides a quantitative basis for tailoring rehabilitation protocols according to disease stage and for evaluating surgical or orthotic interventions by their capacity to normalise these kinematic markers.

Biomechanics of Knee Osteoarthritis publication trend

The graph below shows the total number of articles in biomechanics of knee osteoarthritis across all publications each year (not limited to Nature Index journals).

Technical terms

Ground reaction force: The force exerted by the supporting surface on the body during stance.

Knee adduction moment: An external moment about the knee in the frontal plane, associated with medial compartment load.

Kellgren–Lawrence grade: A radiographic scale for classifying osteoarthritis severity from 0 (none) to 4 (severe).

Inertial measurement unit (IMU): A wearable sensor that records acceleration and angular velocity of body segments.

Tibiofemoral cartilage: The hyaline cartilage lining the surfaces of the femur and tibia within the knee joint.

References

1. Gait, physical activity and tibiofemoral cartilage damage: a longitudinal machine learning analysis in the Multicenter Osteoarthritis Study. British Journal of Sports Medicine (2023).
2. Effect of sensor number and location on accelerometry-based vertical ground reaction force estimation during walking. PLOS Digital Health (2024).
3. Diverse parameters of ambulatory knee moments differ with medial knee osteoarthritis severity and are combinable into a severity index. Frontiers in Bioengineering and Biotechnology (2023).
4. External knee adduction and flexion moments during gait and medial tibiofemoral disease progression in knee osteoarthritis. Osteoarthritis and Cartilage (2015).
5. Relationship between Kellgren-Lawrence score and 3D kinematic gait analysis of patients with medial knee osteoarthritis using a new gait system. Scientific Reports (2017).