Hamstring Injuries in Sport and Activities, Pulled Hamstring
Hamstring injury is one of the most common sporting injuries. The hamstrings are injured most often in sports which involve rapid acceleration and running at top speed. Proper treatment from a physiotherapist is vital to rapid recovery and to reduce the risk of recurrence.
Injury to the hamstrings is the most common injury in many sports, including athletics (especially sprinting), soccer and cricket. Hamstring injuries have been measured making up about 10-15% of all sporting injuries.
Anatomy of the Hamstrings
The hamstrings make up the muscle group at the back of the thigh. There are three hamstring muscles:
You can easily feel the tendons of all the hamstring muscles by pressing your fingers behind the knee on the inside and outside.
The muscles all attach at the upper end to the ischial tuberosities. Pain can be felt in this part of the pelvis but is more common further down. These structures are what we call “the bones we sit on” and you can feel them by putting your hand under you buttock and pushing upwards with your fingers.
The semimembranosus and semitendinosus travel down the back of the thigh and insert on the upper shin bone behind the knee. The biceps femoris attaches to the head of the fibula on the outside just below the knee.
Where Hamstring Injury Occurs
Hamstring injury typically occurs above the lower junction between the muscle and the tendon. This is in the belly of the muscle and is important because if the injury occurs in the tendon or muscle-tendon junction then healing is much slower due to poor blood supply.
The biceps femoris is the most commonly injured muscle and the reason for this is not clear. It is the longest muscle and this could be important but other factors have been proposed.
How Hamstring Injury Occurs
Hamstring injury occurs along a continuum, starting with delayed onset muscle soreness (DOMS) and passing through several stages until the most severe, complete muscle or tendon rupture.
Hamstring injuries have been shown to occur mostly when accelerating in running or running at maximum speed.
The hamstring muscles are capable of generating great forces and due to the fact that they cross both the knee and hip joints they are more liable to injury. This occurs during eccentric contraction when the muscles are lengthening under strain.
The strongest eccentric contraction occurs when the leg is coming through to take another step and hit the ground at speed. As it is coming through the hamstrings are slowing down the forward movement of the hip and the straightening of the knee before the foot hits the ground.
Hamstring injury may also occur just after the foot has hit the ground and the hamstrings are helping the hip extend in the power movement of propelling the body forward.
Hoskins W, Pollard H. The management of hamstring injury - Part 1:Issues in diagnosis. Manual Therapy 10 (2005) 96-107