Sudden pain in the front of the thigh when walking may be related to physiological factors such as strenuous exercise, or pathological factors such as lumbar intervertebral disc herniation and thigh fasciitis. 1. Physiological factors: long walking or strenuous exercise and other reasons, can cause spontaneous muscle tonic contraction phenomenon, there will be the front of the thigh muscle sudden stiffness, pain. This is a normal physiological phenomenon and can be relieved after rest. 2. Lumbar intervertebral disc herniation: commonly found in high lumbar intervertebral disc herniation, due to degenerative changes in the intervertebral disc, which can lead to lumbar intervertebral disc contents protruding backward to stimulate the femoral nerve, causing nerve compression symptoms, pain and numbness in the front of the thigh. 3. Thigh fasciitis: usually due to cold or chronic strain and other factors, resulting in aseptic inflammatory reaction of the local muscles and myofascia, pain in the muscles and ligaments of the anterior thigh can occur. Sudden pain in the front of the thigh when walking may have other causes, it is recommended that patients seek medical attention in a timely manner, improve the examination, targeted treatment or treatment with the help of doctors.