According to the nature of injury, it is classified into:
1. Sprain: Traction and torsion by the indirect violence make the soft tissues around the joint go out of their normal range of physiological activity, hence giving rise to laceration, fragmentation, malposition and joint transposition. The feature is that the injury is far from the force-acting part, mostly around the joint.

2. Contusion: Attack or crush of direct violence on a local part of the body causes a closed trauma of the part. The feature is that the injury occurs at the force-acting area, mainly in soft tissues.

According to the severity of injury, it is classified into:
1. Laceration: There is injury of muscle and tendon or partial fragmentation of tendon because of indirect violence, usually no severe functional disturbance appears.

2. Fragmentation: The pathogenesis is the same as that of laceration, but because of greater force, there is complete fragmentation of tendon, and there often occurs functional disturbance in different degrees, or even deformity.

3. Transposition of bone: There is a little dislocation of a movable or minutely moveable joint because of the action of an external force, it is often a complication of sprain or contusion.

According to the duration of injury, it is classified into:
1. Acute injury of muscle and tendon: Acute injury, also called fresh injury, refers to the injury caused by sudden attack of external force on muscles and tendons of the body, and the duration of injury is not more then two weeks.

2. Chronic injury of muscle and tendon: Chronic injury, called old injury, refers to the condition in which delayed treatment or incomplete treatment for an acute injury may lead to the chronic injury, generally the duration is more than two weeks.

According to whether there is mucocutaneous rupture, it is classified into:
1. Open injury: There occurs breaking of skin when the muscle and tendon is injured, subcutaneous or deep tissues are open to the outside. This kind of trauma is subject to infection.

2. Closed injury: There is no breaking of skin in the injury of muscle and tendon.