- Increased Load: Fins add resistance, increasing stress on the ankle and fibularis longus.
- Repetitive Motion: Continuous flutter kicking stresses the outer calf muscles.
- Poor Fit or Technique: Improper fin use can strain the lateral ankle.
- Muscle Fatigue: Weak stabilizers lead to overload of the fibularis longus.
Signs of strain: Pain or tightness along the outer leg, especially with foot movement or post-swim soreness.