Strains are injuries of your muscles or your tendons, which connect muscles to bone. Typically caused by overuse of muscles and tendons, symptoms of strains can include:
Cramping
Inflammation
Muscle spasm
Muscle weakness
Pain
Swelling
Severe strains can cause your muscle and/or tendon to be partially or completely torn, leading to debilitation. Moderate strains can partially affect muscle function since the muscle or tendon is likely only slightly torn. If you have a mild strain, your muscle or tendon is slightly stretched, not torn.