“Muscle injury” covers all injuries to muscle and the connective tissue within the muscle belly (the main body of the muscle not including the tendons). They are typically graded as:
* Grade 1 – no significant amount of damage to muscle fibres with pain but no or minimal bleeding (generally referred to as a “muscle strain”.
* Grade 2 – a significant, but not complete, rupture of some of the muscle fibres with pain and bleeding.
* Grade 3 – complete rupture of all muscle fibres with discontinuity of the muscle and complete loss of function.
This is an acute (sudden onset) injury to the muscle with varying degrees of severity as per the grading above.
Onset can be felt as a sudden sharp pain or popping sensation or as a painful tightness that builds over a short period of time.
Symptoms only occur on loading although there can be several days of resting pain after onset due to pressure from the bleeding.
Example: Calf tear
This is a sudden injury to the muscle due to external compression, such as impact from an opponent’s knee.
The pain typically builds for the first two days as the bleeding puts pressure on the surrounding muscle.
Contusions cause pain on muscle activation or muscle stretch.
Immediate compression is vital to reduce the severity of the injury and recovery duration.
Other forms of muscle injury
Muscle strain – lay term for muscle injury, typically used for low grade injuries.
Myositis – rare inflammatory reaction throughout the muscle.
Delayed Onset Muscle Soreness (DOMS) – a painful response to unaccustomed exercise due to an uncertain pathological process (many studies have been conducted into DOMS however the mechanism has yet to be clearly defined or agreed on).