Muscle Strain

Original Editor - The Open Physio project.

Top Contributors - Rachael Lowe  


A strain to the muscle or muscle tendon is the equivalent of a sprain to ligaments. A muscle strain occurs when muscle fibres cannot cope with the demands placed on them by exercise overload and leads to tearing of the fibres. It is a contraction-induced injury in which muscle fibers tear due to extensive mechanical stress. This mostly occurs as result of a powerful eccentric contraction or overstretching of the muscle. Therefore, it is typical for non contact sports with dynamic character such as sprinting, jumping… .[1].


Strains are categorized into 3 grades of severity[2][3][4]:

Grade I (mild) strains affect only a limited number of fibers in the muscle. There is no decrease in strength and there is full active and passive range of motion. Pain and tenderness are often delayed to the next day.
Grade II (moderate) strains have nearly half of muscle fibers torn. Acute and significant pain is accompanied by swelling and a minor decrease in muscle strength.
Grade III (severe) strains represent complete rupture of the muscle. This means either the tendon is separated from the muscle belly or the muscle belly is actually torn in 2 parts. Severe swelling and pain and a complete loss of function are characteristic for this type of strain.


Management includes first aid to minimise bleeding and swelling (RICE), electrotherapy modalities (e.g. Ultrasound) to promote efficient scar formation, Massage, stretching and strengthening (in the end stages of healing).

Predisposing factors of muscle strains include; ineffective warm-up, poor flexibility (tight muscles), fatigue, overuse and muscle imbalance (when muscle groups are excessively stronger or weaker in relation to each other).

Related Articles

Compare to ligament sprain

Recent Related Research (from Pubmed)


References will automatically be added here, see adding references tutorial.

  1. Garrett WE. Muscle strain injuries. Am J Sports Med. 1996; 24:S2-88
  2. Tero AH Järvinen, Teppo LN Järvinen, Minna Kääriäinen, Hannu Kalimo, Markku Järvinen. Basic Science Update: Muscle Treatment. Am J Sports;May;33:745-­‐764
  3. Järvinen M, Tero AH. Muscle strain injuries. Rheumatology. 2010(2); 12: 155-161
  4. Kneeland JP. MR imaging of muscle and tendon injury. Eur J Radiol. Nov 1997; 25(3):198-208