A hamstring injury is a strain or tear to the tendons or large muscles at the back of the thigh.
The term 'hamstring' refers to the group of three muscles that run along the back of your thigh, from your hip to just below your knee. They also include the tendons (strong bands of tissue) at the back of the thighs that attach the large muscles to the bone.The hamstring muscles aren't used much while standing or walking, but they're very active during activities that involve bending the knee, such as running, jumping and climbing.
It's a common injury in athletes and can occur in different severities. The three grades of hamstring injury are:
grade 1 – a mild muscle pull or strain
grade 2 – a partial muscle tear
grade 3 – a complete muscle tear
The length of time it takes to recover from a hamstring strain or tear will depend on how severe the injury is.
A minor muscle pull or strain (grade 1) may take a few days to heal, whereas it could take weeks or months to recover from a muscle tear (grade 2 or 3).
Symptoms and Diagnosis
Symptoms of a hamstring strain include a sudden sharp pain at the back of the thigh usually whilst sprinting or a fast stretching movement or high kick.
Grade 1 - With a grade 1 hamstring strain the athlete may have tightness in back of the thigh but will be able to walk normally. They will be aware of some discomfort and unable to operate at full speed. There will be little swelling and trying to bend the knee against resistance is unlikely to reproduce much pain.
Grade 2 - With a grade 2 hamstring strain the athletes gait will be affected and they will most likely be limping. Sudden twinges of pain during activity will be present. They may notice some swelling and pain will be reproduced when pressing in on the hamstring muscle as well as trying to bend the knee against resistance.
Grade 3 - A grade 3 hamstring strain is a severe injury involving a tear to half or all of the muscle. The athlete may need crutches to walk and will feel severe pain and weakness in the muscle. Swelling will be noticeable immediately and bruising will usually appear within 24 hours.
A doctor may order an MRI scan which can help determine the exact location and extent of the injury which can give a more accurate prognosis and estimate of recovery time.
Treatment for a hamstring strain can be categorized into immediate first aid and longer term treatment which begins after the initial acute period has passed.
Immediate first aid consists of the PRICE principles of protection, rest, ice, compression and elevation and will usually last 3 to 4 days depending on severity. A cold therapy and compression wrap should be applied immediately for 10-15 minutes and repeat this every hour for the first day. After this, every 2-3 hours is usually sufficient. A compression bandage or thigh support can be worn to minimize bleeding in the muscle and help control swelling. Rest as much as possible with the leg elevated to hel to help drain away swelling and tissue fluids.
After the initial acute stage has passed hot and cold can be alternated and during the later stages of treatment heat alone is applied for up to 20 minutes to stimulate blood flow and relax the muscles.
Performing foam roller exercises for the hamstrings can massage and apply myofascial release to the muscles. Pressure is applied from just above the knee upwards following the direction of blood flow.
After the initial acute stage very gentle stretching exercises can begin as long as they are pain free. Initially simple static stretching exercises should be done with leg both straight and slightly bent in order to target different parts of the muscle. In the later stages of rehabilitation more dynamic and functional (sports specific) stretching exercises should be done.
Straight leg hamstring stretch - in standing can begin. Place the foot on a table or similar and lean into the stretch keeping the leg straight and chest up. Take the stretch as far as is comfortable and hold relaxing into the stretch. Aim to stretch forward from the hip rather than the shoulders. A gentle stretch should be felt at the back of the leg but it should not be painful. Perform 3 set of 10 seconds once or twice a day. The aim is to get a little bit of elasticity to the healing tissue, not increase flexibility. This can also be done sitting down.
Bent leg hamstring stretch - on the back targets the muscle fibres closer to the hip whereas the straight leg hamstring stretch targets the fibres nearer the knee. Lie on your back and pull the leg over keeping the knee very slightly bent until a gentle stretch is felt at the back of the leg. Again this should not be painful. Perform 3 sets of 10 seconds once or twice a day.
You are ready to move on when you have repeated the above pain free for a minimum of 3 days.
Dynamic hamstring stretching - Begin gentle dynamic stretching. Dynamic stretching involves gently swinging the leg into a stretched position. Ensure the leg is relaxed at all times and the stretch is not forced. Perform 3 x 10 reps gently swinging the straight leg as high as is comfortable. It may help to put the free hand over the swinging leg as a target and to possibly trick the brain into thinking it is safe to swing the leg.
Active straight leg raise - Begin active straight leg raises from lying on the floor. The athlete lifts the injured leg up as far as it will go within the pain free range then lowers again. Perform 3 sets of 10 reps once or twice a day. Try to get a more dynamic movement with this exercise and aim to gradually straighten the knee as flexibility allows.
Strengthening exercises should always be done pain free begin with gentle static or isometric contractions as soon as possible after the initial acute period. The patient will gradually progress through a series of more dynamic and functional exercises involving movement. Eventually sports specific exercises and drills should be performed before returning to full competition or training.
Isometric contractions - The athlete lies on their front in the prone position. The partner or therapist provides resistance as the athlete contracts the hamstring muscles, holds for 3 or 4 seconds then relaxes. The angle of knee flexion is changed and the exercise repeated. Once a range of angles have been worked the whole process is repeated with the foot first turned first inwards then outwards. This exercise targets the inner and outer hamstring muscles at varying angles of flexion or knee bend.
Standing knee flexion - The athlete stands on one leg and bends the other one using gravity as resistance. This can be done gently and slowly to start with as an early stage exercise. Aim for 3 sets of 10 repetitions once a day building to 4 sets of 20 reps. Ankle weights can be used to increase the load further. As the athlete returns to running this exercise can be performed more explosively.
Hamstring catches - The leg is allowed to fall and the hamstring muscle catches the leg before it falls to the horizontal. It may take a while to get used to this one. The athlete must stay relaxed as the leg falls under the influence of gravity and only contracts the hamstring muscles to prevent the foot landing. This starts to work the muscles eccentrically with a very light dynamic training effect. This should be done pain free both during, afterwards as well as the next day. A little bit of natural muscle soreness the following day is OK but if it is uncomfortable then take a step back. Again begin with 1 set of 10 reps and build up each day to 3 sets of 15 reps. An ankle weight can be used to increase the load on the muscle.
Seated hamstring curl - This is a deceptively difficult exercise which works the hamstring muscles specifically in a very contracted close range of movement.One end of a resistance band is tied to a fixed point or held by a partner and the other end secured to the foot. The athlete pulls the heel into the buttocks contracting the hamstring muscle to do so. Aim for 3 sets of 8 reps to begin building up to 3 sets of 12 or 15.
Single leg ball pick up - This is another deceptively difficult hamstring exercise which looks easy at first glance. However with this one it is important to judge muscle soreness the next day before over doing this one. It works the hamstring muscles in a very stretched position, particularly the muscle fibers nearer the buttocks.
The athlete places on foot in front of the other and bends down to pick up the medicine ball. They then repeat the movement to put the ball back down. Repeat this 5 to 10 times.
Lunge with ball - A basic lunge is performed while holding a ball to aid balance. This exercise strengthens the glutes, hamstring muscles and quadriceps muscles. The athlete stands with the injured leg a wide stance in front of the other. Holding a medicine ball close to the chest the weight is shifted onto the front leg and back knee bent dropping it down to the floor.
Nordic leg curl - One of the most advanced hamstring exercises. The athlete kneels down while the therapist holds the ankles. They then slowly lean forwards as far as they can under control using the hamstrings to resist the forwards movement. A super advanced version of this is to use the hamstrings to curl back up again.
After these exercises start to become easy and completely pain free, you can consider the rehabilitation to be done. However, keep frequently performing hamstring exercises as this will help decrease the chance of re-injury.