Types of Muscle Injuries

In 2013 the most respected Sports Physicians and other Healthcare Professions such as Physiotherapists, were given a questionnaire on muscle injuries and how to classify such injuries.

Why is this even important?

Firstly, if all Healthcare professionals can have the same criteria for diagnosing injuries then this makes it a lot easier when deciding on treatment and prognosis. For example, if a footballer has a Grade I injury to the Hamstring, then you can predict with some accuracy that they will be out of action for about 7-10 days. But what if after an MRI and Physical Examination, another Physiotherapist or Doctor decides that in their opinion it’s a Grade II injury? Since their criteria is different to diagnose the injury, the incorrect time frame for a return to play or treatment may be given. The only person who loses out is the injured person in question.

Secondly, classifying all types of injuries from lower back pain to tendinopathy make researchers’ life a lot easier. If researchers want to decide on what the best treatment for a Hamstring strain is then they would want to test a treatment in a group that has the same type of Muscle Injury. This keeps the population of the study as equal as possible and therefore guides Physios and Doctors on what the best treatment is.

For example, if a group of 10 people with a Type I Hamstring Injury undergo an exercise regime and they all get better quickly, then you could presume that the exercise regime is helpful for those with a Type I Hamstring injury. What if in that group of 10 people, there were 6 people with a Type II Hamstring Strain? Now if the results showed that only 6 out of 10 people in the study got better, you cannot say that the exercise regime didn’t help because the group had different injuries. It’s basically not comparing like with like.

So if there are clear guidelines on how to classify injuries then best practices can be delivered to the injured person.

Here is a simplified version of The Munich Consensus Statement of terminology and classification of Muscle Injuries, with some comments from myself.

TypeClassificationMyPhysio Comments
1aFatigue-Induced Muscle DisorderLow-level pain to muscle often due to an intense bout of exercise.
1bDelayed Onset of Muscle Soreness (DOMS)Muscle pain due to a new type of exercise or exercise following a period of no exercise. Resolves after 2-3 days
2aSpine Related Neuromuscular DisorderIncrease in muscle tone due to spinal or pelvic disorder e.g. lumbar disc protrusion
2bMuscle-Related Neuromuscular DisorderIncrease in muscle tone often due to weakness of nearby muscles.
3aMinor Partial TearA tear smaller than a muscle fascicle
3bModerate Partial TearTear greater than a muscle fasicle
3cTotal Muscle TearComplete separation of muscle fibres
4ContusionThis is a direct impact to the muscle e.g. a dead leg


Wohlfart, et al., 2013. Terminology and Classification of Muscle Injuries in Sport: The Munich Consensus Statement. British Journal of Sports Medicine.