Hamstring Injury
Muscle injuries are the most common injuries in sports, accounting for around 45 % of all injuries in football.
Hamstring injuries are the most common, with the biceps femoris being the most commonly injured muscle. The hamstring muscles are divided into the biceps femoris, the semitendinosus and the semimembranosus muscle. The function of these muscles is knee flexion and hip extension.
There are several grades of muscle injury. The British Athletics Muscle Injury classification grades muscle injuries according to the extent (grades 0 to 4) and the location (a, b and c) of the injury. The following grades are used:
- Grade 0: positive clinical result, negative imaging findings:
- Grade 0a: myofascial focal neuromuscular injury;
- Grade 0b: myotendinous junction focal neuromuscular injury.
- Grade 1: small muscle tear (less than 10 % of the muscle or less than 5 cm in length):
- Grade 1a: small myofascial tear;
- Grade 1b: small myotendinous junction tear.
- Grade 2: medium-sized muscle tear (between 10 % and 50 % or between 5 cm and 15 cm in length):
- Grade 2a: myofascial or moderate muscle belly tear;
- Grade 2b: moderate myotendinous junction tear;
- Grade 2c: tendon tear less than 50 % or 5 cm in length.
- Grade 3: severe muscle tear (more than 50 % of the muscle or more than 15 cm in length):
- Grade 3a: large myofascial or muscle belly tear;
- Grade 3b: large myotendinous junction tear;
- Grade 3c: tendinous tear greater than 50 % or 5 cm in length.
- Grade 4: complete muscle tear (100 %):
- Grade 4c: complete tendon tear or avulsion.
Causes and risk factors
Most of these types of injuries occur during sprinting. They are therefore more common in sports that involve acceleration, deceleration and change of direction.
Risk factors for muscle injury include: previous injury, muscle composition and architecture, age and race (unchangeable factors) and muscle length, muscle imbalance, fatigue, associated back injury, poor pre-exercise warm-up, poor flexibility and increased muscle tension (changeable factors).
Treatment
Rehabilitation varies according to the severity and location of the injury and can be divided into several phases. In the acute phase, the use of ice and compression is recommended, together with manual therapy during a physiotherapy session. In the sub-acute phase, light isometric and eccentric exercises should be introduced, without neglecting manual therapy, diathermy (TECAR) and TENS (electrotherapy). If there is no pain on eccentric contraction and palpation, then maximum strength training should be introduced, focusing on the eccentric phase of the exercise. As soon as the symptoms disappear and muscle strength tests, often supported by isokinetic testing, show a deficit of less than 20 %, it is time to introduce running and, after the gym and specialised field work, a return to sports with a customised programme.
If you need treatment for a hamstring injury, contact our physiotherapy clinics in Lisbon.
