User:Ducky2315/sandbox

Cause
The most common theories thought to cause Achilles tendinitis are based on physiological, mechanical, and extrinsic properties (i.e footwear or training types). Physiologically, the Achilles tendon is subject to poor blood supply through the synovial sheaths that surround it. This lack of blood supply can lead to the degradation of collagen fibers and inflammation. Tightness in the calf muscles has also been known to be involved in the onset of Achilles tendinitis. During the loading phase of the running and walking cycle, the ankle and foot naturally pronate and supinate by approximately 5 degrees [4]. Excessive pronation of the foot (> 5 degrees) in the subtalar joint is a type of mechanical mechanism that can lead to tendinitis.

An, overuse injury, refers to repeated stress and strain, which is likely the case in endurance runners. Overuse can simply mean an increase in running, jumping or [[plyometric exercise] intensity too soon. Another consideration would be the use of improper or worn-down footwear, which lack the necessary support to maintain the foot in the natural/normal pronation [5].