Failure to hook the foot may be caused by ankle joint injury, peroneal nerve palsy, lumbar disc herniation and so on. 1. Ankle joint injury: when the muscles and tendons around the ankle joint are injured, or even when the ankle joint is fractured, it can lead to swelling around the ankle joint, limiting the movement of the joint, and resulting in the inability to hook up the feet. 2. Peroneal nerve palsy: when the peroneal nerve is affected by trauma, infection, compression and other factors, it can lead to sensory abnormalities and motor disorders of the foot and calf, making the affected side of the foot unable to hook up. 3. Lumbar disc herniation: Lumbar disc herniation can compress the peripheral nerve roots of lumbar vertebrae, sciatic nerve and spinal cord and other tissues, due to the sciatic nerve compression can cause foot prolapse, resulting in the foot can not be hooked up. The inability to hook up the feet can also be caused by other reasons, it is recommended to improve the electromyography and other related examinations to clarify the cause of the disease and then carry out targeted treatment.