A slip of pain in the outer tendon of the leg may be caused by muscle strain, soft tissue contusion, soft tissue tumor, lumbar intervertebral disc herniation and other factors. 1. Muscle strain: the disease is due to the injury caused by the sharp contraction or pulling of muscles during exercise. After the muscle strain of the outer thigh, local pain may occur, which may also be accompanied by redness, swelling, muscle spasm, muscle weakness and other symptoms. 2. Soft tissue contusion: this disease is mainly caused by impact and sprain, etc. After the muscle tissues of the outer thigh are contused, inflammatory reaction will occur, causing painful symptoms. 3. Soft tissue tumor: the disease is a tumor that appears in the fibrous tissue, transverse muscle tissue and other parts of the body, due to the tumor pressure on the normal tissues, the patient will experience pain, which may also be accompanied by local temperature increase, swelling of nearby lymph nodes and other symptoms. 4. Herniated lumbar intervertebral disc: Herniated lumbar intervertebral disc may involve the lumbar nerves, leading to the symptoms of pain in the outer thigh and inner thigh. A sliver of pain in the outer tendon of the leg may also be related to lumbar disc herniation, muscle tear and other factors, and it is recommended that the patient go to the hospital for timely consultation and treatment.