At the hip, the hamstrings play a role in a posture condition known as flat low back. Tight hamstrings may also play a role in sacroiliac dysfunction. Become acquainted with each of the hamstring muscles , including where they attach and what they do. The hamstrings are a group of four muscles: long head of the biceps femoris, short head of the biceps femoris, semitendinosus, and semimembranosus.
Each hamstring crosses two joints—the hip and the knee. This means when they contract they can either take your lower extremity back behind you called hip extension or bend the knee called knee flexion. The biceps femoris muscle is one of the big, long muscles at the back of your thigh. The other one is the semitendinosis; the biceps femoris is lateral, or toward the outside relative to the semitendinosis. The biceps femoris has two heads—a long and a short.
At the hip, both the long and short heads rotate the thigh outwardly and extend it backward. At the knee, they flex and laterally rotate the joint. Of all the hamstring muscles, the biceps femoris is the biggest contributor to hip extension. The long head of the biceps femoris originates on the inner side of your sitting bones, which are little knobs of bone that are technically called the ischial tuberosities.
The ischial tuberosities are located on the underside of your pelvis. You likely can feel them when you sit down. The short head of the biceps femoris originates on three places on the femur i. Note that the short head of the biceps femoris is the only part of the hamstring muscle group that does not cross two joints. It's actually missing in some people. Both the long and short head of the biceps attach on the lower leg, also in three places: The head of the fibula bone, the outer called lateral condyle of the tibia bone, and the fascia of the leg.
The multitude of attachment sites on the lower leg may make for more tears here than in the other hamstring muscles. The semitendinosus is another long, big hamstring muscle. At first glance, it is situated medially, or toward the inside of the back of the thigh, relative to the biceps femoris. The semitendinosus originates at the inner side of your sitting bone. The semitendinosus extends the thigh backward and allows for the medial rotation i.
The most medial muscle, the semimembranosus inserts on the inner portion of the shin bone. Like the semitendinosus, the semimembranosus is a broad muscle, though it is more tucked away. It originates at the sitting bones, similar to the other muscles in the hamstring group.
However, it attaches higher up. It also connects to the inner portion of the upper tibia knee joint. The semimembranosus extends the hip joint and flexes and also medially rotates the knee toward the midline.
Overuse injuries to the hamstrings are common, particularly in sports like soccer , football, basketball, and tennis , where running is combined with rapid starts and stops. The long head of the biceps femoris is particularly prone to injury in sports such as these, likely because it exerts the most force compared to the other muscles in the hamstring group.
Hamstring sprains and tears are also relatively common. And they can become more serious when there is significant bruising behind the thigh.
Repetitive stress injuries from running or walking are also a common cause of hamstring pain and injury. The onset of injury to the hamstring muscle group is often sudden and is usually identified as a strain sprain or tear or contusion bruising. Strains range from mild to severe and include the following traits. Contusions are caused by an external force making contact with the hamstring muscles, such as with many contact sports. Symptoms of contusions include:.
If pain resulting from a hamstring injury does not resolve in a few days or is inhibiting your ability to walk normally and perform everyday activities, see your doctor for a diagnosis and treatment.
If you play a sport and sustain a hamstring injury, you will likely need to fully rehabilitate before returning to normal activity. This will allow the muscle group ample time to recover and repair, which can help prevent a relapse. Walking, running, and climbing and descending stairs all help to build the functional fitness of the hamstring muscle group.
Hamstring exercises can be beneficial for anyone, but they can be especially helpful for people who run or cycle , both of which target the quadriceps. It's important to balance the development of the quadriceps with cross-training that includes adequate strength and conditioning of the hamstrings. Various isolation and compound exercises for the hamstrings can also be employed in rehabilitation settings or in bodybuilding.
Exercises that involve knee flexion and hip extension are commonly used to build the hamstring muscles. Here are a few fundamental moves to try. Hamstring flexibility is important for runners and may help prevent injury and delayed onset muscle soreness DOMS after exercise. Tight hamstrings may limit your range of motion when you straighten your knee. You might also feel a cramp at the back of the knee. Hamstring stretches can be incorporated into just about any regular stretching and flexibility routine.
The following hamstring stretches can be performed daily to improve flexibility, promote recovery, and prevent injury. Get exercise tips to make your workouts less work and more fun. Rehabilitation of hamstring muscle injuries: A literature review. Rev Bras Ortop. Ernlund L, Vieira L de A. It gained the meaning of the leg of an animal around the 15th century.
These are the muscles traditionally taught to be hamstrings. In the hollow behind your knee, there are nine tendons. When you want to flex your knee, the brain recruits any muscles that have the ability to perform this action AND that are strong enough to meet the demand force being placed on them. All three perform hip extension and knee flexion. They each contribute to motion in the frontal and transverse planes as well.
You have several other muscles performing knee flexion. Introducing your nine knee flexors:. True Hamstrings knee flexion and hip extension Semimembranosus: ischial tuberosity TO posterior back superior upper tibia Semitendonosus: ischial tuberosity TO medial inner superior upper tibia Biceps Femoris long head: ischial tuberosity TO head upper of fibula. These are the big cords that can be felt behind the knee joint. Then, you can forget the complicated terms and know by sense where they attach.
The 4th Hamstring knee flexion only Biceps Femoris short head: head upper of fibula TO lower lateral third of femur. The Lower Hamstrings Gastroc Nemius lateral — achilles tendon calcaneus TO lateral condyle of femur Gastroc Nemius medial — achilles tendon calcaneus TO medial condyle of femur Plantaris — achilles tendon calcaneus TO lateral condyle of femur. True Hamstrings? The popliteus and short head of biceps femoris are the only two out of theses nine that ONLY flex the knee.
Stop Memorizing In my anatomy courses, I emphasize that trainers only memorize one thing. The insertions of the muscles. I call both sides insertions, because it gets confusing trying to remember which is origin and which is insertion. If you know the attachment insertion points of a muscle, you can always figure out the actions and then create exercises. See how…. Muscle Actions Get a rubber band or balloon something stretchy and find each side of the muscle on the body.
Put one end of the stretchy item on each insertion point on yourself or a partner. Explore what joint actions will shorten the rubber band by moving the joint in different directions. Some movements will lengthen the rubber band stretch and others will shorten contract it.
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