Altered knee joint loading in patients with chronic ankle instability during running

Area of Science:

• Biomechanics
• Orthopedics
• Sports Medicine

Background:

• Chronic ankle instability (CAI) alters lower extremity biomechanics, potentially increasing joint loading.
• Understanding these biomechanical changes is crucial for detecting early degenerative joint disease.

Purpose of the Study:

• To compare knee joint contact forces (JCF) during running in individuals with CAI versus healthy controls.
• To identify lower extremity muscles contributing to these forces in CAI.

Main Methods:

• Musculoskeletal simulation used to estimate tibiofemoral joint forces (compressive, shear) during running.
• Analysis included muscle contributions and ground reaction forces (GRF).
• Statistical parametric mapping and independent t-tests were applied.

Main Results:

• Individuals with CAI exhibited greater posterior and medial knee shear forces during running compared to controls.
• Compressive impulse was significantly higher in the CAI group, though peak compressive force did not differ.
• Increased knee JCF in CAI was predominantly driven by enhanced quadriceps muscle activity.

Conclusions:

• Greater knee joint loading in CAI is linked to increased quadriceps muscle contributions.
• Findings emphasize the biomechanical connection between ankle and knee joint health.
• Rehabilitation focusing on proximal muscle coordination may mitigate knee joint loading in CAI patients.