Rupture of the Hamstrings Tendon / Tendon Strain
The term hamstring refers to the posterior thigh muscles. These are three in number and originate from the pelvic bone, extend downwards, crossing both hip and knee joints at the back of the leg, and finally insert into the lower leg bones. The tendons of these muscles (the fibrous extensions connecting muscles to bones) are also denoted by the same term (ham refers to the fat and muscle at the back of the thigh while string means cord).
These tendons are quite prominent and can be easily felt as strong, cord-like structures behind the knee. The posterior thigh muscles cross two joints and are therefore involved in movements along both the hip and the knee. The hamstring tendons, therefore, play an important role in walking, running, climbing steps, jumping, etc.
Hamstring rupture is a common occurrence among athletes, especially those playing sports that involve sprinting or jumping movements such as rugby, soccer, basketball, etc. A hamstring may also rupture during waterskiing when the skier falls forward, leading to sudden hip flexion while the knee is fully extended; it may happen while performing splits.
A tendon injury or strain almost always results from stretching a muscle or tendon beyond its normal limit. A stiff, weak or poorly conditioned muscle that has a strong antagonist (muscle that opposes its action, in this case the quadriceps) is at an increased risk of acquiring injury.
Hamstring rupture occurs either in the full thickness of the muscle or where the muscle fibres blend into the tendon, i.e., the junction of muscle and tendon. Rupture may also occur at the point of insertion of the tendon in the bone. It may be severe enough to cause fracture of the bone chip that tears away along with the detached tendon; this is referred to as an avulsion fracture.
- A sudden piercing pain at the back of the thigh, there may also be an audible popping sound.
- Swelling and bruising follows soon afterwards
- Pain intensifies when the knee is flexed against resistance, one walks with a stiff leg to avoid movement at the hip or knees
- The person is unable to put weight on the affected side; sitting, climbing stairs or walking uphill all become painful.
The immediate treatment is to stop the activity, raise the leg off the ground, with no weight bearing on the affected side. Apply ice packs, slight compression at the site and elevate the leg to minimise pain and swelling.
Conservative therapy focuses on immobilising the knee for a certain period, followed by rehabilitation.
Surgery is highly recommended in case of complete tearing or when an avulsion fracture has occurred. The operation involves stitching together the torn muscle fibres or reattaching the detached tendon to the bone with the help of pins and staples in the case of an avulsion injury.
The recovery period varies with the type and extent of injury. Nevertheless, a complete rehabilitation program is advised whether the injury is treated conservatively or through surgical approach. The rehabilitation process consists of three main steps:
- Complete rest and support to the injured hamstrings (through the RICE protocol) until the initial symptoms of pain and inflammation subside
- Stretching should be started early in the treatment to improve flexibility and range of motion
- Later on, when the injured hamstrings have sufficiently recovered, and movements are pain free, muscle strengthening exercises should commence.
In the first phase it is advisable to avoid any weight-bearing or painful activity. Movement is allowed only with the help of crutches or braces. Once the area is pain free, mild range of motion exercises involving the front thigh muscles (quadriceps) and calf muscles can be started.
In the second phase, approximately a week or two later, mild hamstring stretching is initiated. Several exercises can commence at this stage such as hip extension and sideways movement.
These stretches help to align the scar tissue (repair tissue forming at the site of injury) thus improving its strength. It is essential to avoid exertion or stretching to a painful limit as it may delay the healing process and may do more harm than good.
When the movement is comfortable, hamstring strengthening exercises can be included in the program. Lying on a mat, face upwards, the heel is brought slowly towards the buttocks, to the extent that it does not cause any pain. This is repeated several times, avoiding pain. Later on, the same leg curls can be performed in a standing position. Reverse straight leg raises or leg curls against resistance using ankle weights or gym equipment can be added on later. Swimming, stationary cycling, and treadmill walking can also be started, gradually increasing the pace and duration.
Sports massage is an important part of a rehabilitation program. It helps to improve the drainage and blood supply to the injured tissue, speeding recovery. Further it also increases tissue flexibility and allows for the formation of a healthy scar.
Rehabilitation may take several months – go slow and steady for best results. Following a proper rehabilitation plan avoids complications during healing, as well as any risks of future injury.