Foot sprains mostly refer to ankle sprains, and leg thinning after ankle sprains is mostly seen in muscle atrophy of the lower limbs, which is caused by less activity after sprains. 1. After ankle sprain, because of local pain and dare not go down to the ground activities, for a long time the muscles of the lower limbs, such as gastrocnemius muscle, flounder muscle, quadriceps muscle atrophy, which is manifested in the lower limbs become thin, the lower limbs of the strength will also have a certain degree of weakening, is a normal phenomenon. 2. Wait until the foot sprain or ankle injury recovery, can be normal activities, you can start to exercise the muscles of the lower limbs, muscle atrophy can be gradually recovered. If the ankle sprain is more serious, the symptoms continue not to ease, calf thinning is more obvious, it is recommended to consult a doctor in a timely manner, in accordance with the doctor’s instructions for treatment.