We specialise treating hamstring pain and tears at our Galway-based physiotherapy clinic. Hamstring strains are caused by a rapid extensive contraction or a violent stretch of the hamstring muscle group which causes high mechanical stress. This results in varying degrees of rupture within the fibres of the musculotendinous unit.

Hamstring strains are common in sports with a dynamic character like sprinting, jumping, contact sports such as Hurling, Gaelic football, American football and soccer where quick eccentric contractions are regular. It is the most frequent injury in soccer. Hamstring injuries can also occur in recreational sports such as water-skiing and bull riding where the knee is forcefully fully extended during injury.

The hamstring consist of three muscles:

1) The biceps femoris
2) The semitendinosus
3) The semimembranosus

Causes

The cause of a hamstring muscle strain is often obscure. In the second half of the swing phase, the hamstrings are at their greatest length and at this moment, they generate maximum tension. In this phase, hamstrings contract eccentrically to decelerate flexion of the hip and extension of the lower leg. At this point, a peak is reached in the activity of the muscle spindles in the hamstrings. A strong contraction of the hamstring and relaxation of the quadriceps is needed.

Predisposing and Risk Factors

There are various proposed risk factors which may play a role in hamstring injuries:

• Older age
• Previous hamstring injury
• Limited hamstring flexibility
• Increased fatigue
• Poor core stability
• Strength imbalance
• Ethnicity
• Previous calf injury
• Previous substantial knee injury
• Osteitis pubis

Grades of Injury

Hamstring strains are categorised in 3 groups according to the amount of pain, weakness, and loss of motion:

• Grade 1 (mild): just a few fibres of the muscle are damaged or have ruptured. This rarely influences the muscle’s power and endurance. Pain and sensitivity usually happen the day after the injury (depends from person to person). Normal patient complaints are stiffness on the posterior side of the leg. Patients can walk fine. There can be a small swelling but the knee can still bend normally.
• Grade 2 (medium): approximately half of the fibres are torn. Symptoms are acute pain, swelling and a mild case of function loss. The walk of the patient will be influenced. Pain can be reproduced by applying pressure on the hamstring muscle or bending the knee against resistance.
• Grade 3 (severe): ranging from more than half of the fibres ruptured to complete rupture of the muscle. Both the muscle belly and the tendon can suffer from this injury. Patients experience massive swelling and pain. The function of the hamstring muscle cannot be performed anymore and the muscle shows great weakness.

Treatment

• Protect healing tissue
• Minimize muscle wasting and strength loss
• Prevent motion loss

Precautions

• Avoid excessive active or passive lengthening of the hamstrings
• Avoid antalgic gait pattern

Rehabilitation

• Ice – 2-3 times daily
• Stationary bike
• Sub-maximal isometric hamstring strengthening at 90, 60 and 30
• Single leg balance
• Balance board
• Soft tissue mobilisations
• Progressive hip strengthening
• Pain-free isotonic knee flexion
• Active sciatic nerve flossing

If you are unsure about the specific type or grade of hamstring injury you are suffering from, it is important to speak to your physiotherapist. They will be able to assist you and advise you on what to do and what not to do. Here at West Coast Physio, we are more than happy to help you.