The common causes of lateral calf tendon pain include improper exercise, fasciitis, lumbar disc herniation, etc. 1. Improper exercise: Exercise is too large or too long, causing muscle strain and increased lactic acid, which can cause lateral calf tendon pain. 2. Fasciitis: If the outer calf is repeatedly stretched, the muscle is in a state of spasm and contraction, and you will feel pain in the outer calf tendon. 3. Lumbar disc herniation: herniation can compress the nerve root and cause lateral calf tendon pain. Cause lateral calf pain, there may also be other reasons, such as trauma, pear-shaped muscle syndrome, etc. It is recommended to go to the hospital in a timely manner to improve the examination, to clarify the cause of the disease, and standardized treatment under the guidance of the doctor.