Muscle Strain

A muscle strain is an injury to a muscle or tendon, the fibrous tissue that connects muscle to bone. Minor injuries can stretch a muscle or tendon, while more serious injuries can cause partial or complete tears in these tissues. Sometimes called muscle strains, strains often occur in the lower back and muscles on the back of the thigh (hamstring). The difference between a strain and a sprain is that a strain involves an injury to a muscle or the ligament that connects a muscle to a bone, while a sprain injures the ligaments that connect two bones.