Sprains are tears of the non-contractile supporting structures of the joints, ligaments and capsule. These structures consist of limited elastic collagen tissue that intimately attaches one articulating bone to another. Further, damage to the capsule leads to loss of nutrients and lubrication fluid (synovial fluid) of a joint, leading to serious joint damage. Similar to strains, sprains are likewise categorised as follows:

Grade I – involves the tearing of a minimal number of ligament fibres. There may be pain, swelling, and some loss of motoric function.

Grade II – involves a moderate or partial ligament tear. There is moderate to severe pain, swelling, tenderness and loss of joint function. Added to this is the loss of functional ability such as walking.

Grade III - involves the complete tearing of the ligament or joint capsule, which is sometimes accompanied by avulsion fractures. It is associated with severe pain, swelling and loss of function and most often requires immobilization and/or surgical intervention.