A hamstring injury can cause you to literally stop in your tracks. To understand how they occur, you need to know what the hamstrings do and where they are located. Hamstrings are the tendons that attach the large muscles at the back of the thigh to the bone. They are the large muscles that pull on these tendons, from the hip to the knee, allowing your leg to bend and straighten. The anatomically correct names for the three muscles are known as the femoris, the semitendinosis and the semimembranosis muscle. These muscles start right below your buttocks at the bone on which we sit, known as the ischium, and connect through their tendons to the lower parts of the leg bones known as the tibia and fibula.
The hamstring muscles are responsible for allowing your knee to bend, and also straighten and extend through your hip, allowing your thigh to move behind you as you walk. Though these muscles are not as active while walking or standing, they are very important for more strenuous types of movements like running, jumping and climbing. This is why athletes rely on healthy, physically conditioned hamstring muscles.
A hamstring injury can range from a minor strain to a major rupture, or tear of the muscles. A minor strain is classified in medical terminology as a grade one tear. These types of injuries tend to be mild, with minor pain and can fully heal. Partial ruptures or tears are classified as a grade two tear, a bit more severe than grade one, causing a small amount of more pain and longer time to heal. A complete rupture or tear to your hamstring muscles is classified as a grade three tear. These occur more frequently in individuals who are very athletic, like runners, and can be severely debilitating, causing impaired functions.
A hamstring injury usually occurs with sudden movements, while jumping, running or lunging. This sudden movement or jerking motion pulls on the tissues of the hamstring, and can result in a rupture or tear of these tissues. This can be a minor spasm with mild pain, or can be severe enough to stop you from movement altogether. The more severe injuries can also include the area to become swollen and bruised.