A strain is an injury to either a muscle or a tendon, the tissue that connects muscles to bones. The 3
grades of a muscle strain are:
Grade 1- This is a mild strain and only some muscle fibres have been damaged.
Grade 2- This is a moderate strain, it is more extensive damage to the muscle fibres but the
muscle is not completely ruptured.
Grade 3- This is a severe injury with a complete rupture of the muscle. This typically requires
a surgical repair.
Muscle Strain Damage response
After suffering a muscle strain, the body will give an inflammatory response to the injury which will
last 3-5 days. This means that the body will remove dead muscle fibres in anticipation of the healing
response.
Healing response
1. Regeneration of the muscle fibres- Muscle fibres grow from cells in the muscle.
2. Formation of scar tissue- There is bleeding in between the torn muscle ends. This causes a
scar to form in the muscle which makes the muscle more resistant to damage.
3. Maturation of the scar tissue- The fibres which make up the scar tissue become aligned and
are able to withstand more force.