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 and jumping.
Strains are categorized into 3 grades of severity
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.
A number of factors predispose an athlete to muscle strains:
- Inadequate Warm-up
- Insufficient Joint Range of Motion
- Excessive Muscle Tightness
- Fatigue / Overuse / Inadequate Recovery
- Muscle Imbalance
- Previous Injury
- Faulty Technique / Biomechanics
- Spinal Dysfunction