The ankle arch plays an important role in protecting the knee joint from excessive stress and reducing the risk of osteoarthritis (OA) knee. A healthy medial longitudinal arch acts as a natural shock absorber and helps maintain proper alignment of the lower limb during standing, walking, and running.
When the arch collapses (flatfoot/overpronation), the foot rolls inward excessively, causing abnormal rotation of the tibia and altered knee biomechanics. This increases medial compartment loading, knee adduction moment, and stress across the knee joint, especially during walking and stair climbing.
A healthy ankle arch helps:
- Maintain proper lower-limb alignment
- Improve shock absorption
- Reduce abnormal rotational stress on the knee
- Improve gait mechanics and balance
- Distribute body weight more evenly
- Reduce excessive medial knee loading
- Protect cartilage from early degeneration
When combined with obesity, muscle tightness, weak hip muscles, poor posture, and varus alignment, flatfoot further increases the risk of pain, stiffness, and progression of OA knee.
Proper footwear, arch support, strengthening of foot and hip muscles, stretching, gait correction, and biomechanical rehabilitation may help improve lower-limb alignment and reduce stress on the knee joint.