What is a hamstring injury?
Hamstring muscle strain injuries are one of the most common injuries in football. A hamstring injury is a strain or tear to the tendons or large muscles at the back of the thigh and occurs when one of the three muscles that run along the back of your thigh is strained or pulled. Hamstring injuries are graded according to their severity: grade 1 – a mild muscle pulls or strain, usually heals readily; grade 2 – a partial muscle tear; and grade 3 – a complete muscle tear, that may take months to heal.
What are the signs and symptoms?
- Sudden and severe pain during exercise, along with a snapping or popping feeling
- Pain in the back of the thigh and lower buttock when walking, straightening the leg, or bending over
- Swelling and tenderness, usually developing within a few hours
- Bruising or discoloration along the back of the leg
- Muscle weakness or an inability to put weight on injured leg
What are the causes?
Hamstring injuries are associated with sports that involve rapid acceleration or deceleration, jumping, cutting, pivoting, turning or kicking. A vicious cycle of re-injury is not uncommon, resulting in significant morbidity in terms of symptoms, reduced performance, and time loss from sport. Recurring injury is common in athletes and sportsmen. There are two main mechanisms involved in thigh muscle injuries: direct (contusion) injuries, and indirect (distension or strain) injuries. A contusion injury is typically caused by a direct blow from an opponent, usually the knee hitting the lateral thigh in a tackle (a.k.a. ‘charley horse’ or ‘cork thigh’). The muscle is thereby crushed between the opponent’s kneecap and their own femur. Hamstring injury risk factors include: age, previous injury, poor flexibility, poor hamstring strength, and sports participation.
How is it diagnosed?
Diagnosis begins with a clear history of the player, and muscle injuries are diagnosed by physical examination that includes careful assessment of the hamstring range of motion in both a straight leg raises and hip flexed position. Pain on contraction from a resting and extended position will be assessed. X-rays can check for avulsion fractures, while ultrasound and MRIs can visualise tears in the muscles and tendons. An MRI will also determine the exact location and extent of injury, and an ultrasound is a very useful tool in muscle injuries follow-up.
How is it treated?
The initial goal of treatment is to reduce pain and swelling, and help the athlete return to all activities. Most hamstring strains heal very well with simple, nonsurgical treatment such as rest, ice, compression, and elevation. After the initial pain and swelling of a hamstring injury subside, a physical therapist will assist in performing specific exercises designed to improve flexibility and strengthen the hamstring muscles. Surgery is required if the muscle has pulled free from where it's connected to your pelvis or shinbone, and severe muscle tears also can be repaired. After surgery, rest and physical therapy will gently improve flexibility and range of motion, with strengthening exercises gradually added.
How can it be prevented?
Prevention is especially relevant in players with known risk factors for hamstring injuries such as age, previous injuries, and knee ligament injuries, and program should be individualised after physical examination. Primary prevention should focus on monitoring training and competition loads, as well as strength training as part of daily training. As part of an overall physical conditioning program, regular stretching and strengthening exercises can help minimise the risk of hamstring injury.