Hamstring Muscle includes three muscles located on the back of the thigh. These three muscles are:
- Biceps Femoris muscle: This muscle is located behind and outside the thigh and includes a long and short head.
- Semitendinosus tendon muscle: located behind and inside the thigh. (superficial)
- Semimembranosus poisonous muscle: This muscle is located behind and inside the thigh under the poisonous tending muscle. (deep)
The membranous, tendinous, and long head of the biceps muscle begins above the lowest part of the hip bone, which is called the Ischial tuberosity, and the short head of the biceps begins at the dorsal surface of the femur.
The biceps femoris muscle is attached to the outer part of the head of the fibula bone and the outer condyle of the tibia bone, and the membranous and tendinous muscles are attached to the top and inside of the tibia.
Because these three muscles are close together and do almost the same work, their collection is called the hamstring muscles.

Hamstring Muscle Injuries
- Hamstring muscle injuries such as hamstring muscle strain are common in athletes (mostly in sports such as running, football, and basketball) and can be very painful.
- Hamstring injuries can occur in the form of a mild strain of the muscle that is easily treated, a partial tear of the muscle, or a complete tear of the muscle that takes months to heal.
- Most hamstring injuries occur in the thicker middle part of the muscle or where the muscle fibres connect to the tendon fibres.
- In more severe hamstring injuries, the tendon may be wholly separated from the bone or even take a part of the bone with it, called an avulsion fracture.
Hamstring injuries usually occur when the muscle is stretched while it is contracted. (Eccentric contraction) This can happen in sprinting.
Causes of Hamstring Muscle Injuries
Risk factors that can increase the possibility of hamstring muscle injuries include:
Muscle Stiffness
Muscle stiffness increases the possibility of hamstring strains and injuries. Stretching reduces the possibility of hamstring injuries.
Muscle Inconsistency
When one muscle group is much stronger than the opposite, the possibility of muscle strain increases; for example, the quadriceps, which are located in front of the thigh, are usually more substantial than the hamstring muscles, which are located behind the thigh.
And during sports activities, the hamstring muscles are tired earlier, and this fatigue can lead to stretching of the hamstring muscles.
Muscle Weakness
If muscles are weak, they have less tolerance to the pressure of sports exercises, and as a result, muscle damage is more common.
Muscle Fatigue
Fatigue reduces the ability of the muscle to absorb shock and energy. As a result, the possibility of muscle damage increases.
Type of Activity
Sports with a higher risk for hamstring injury include running, football, and basketball. Also, older athletes and young developing athletes are more prone to hamstring injuries.

Symptoms of Hamstring Muscle Injuries
The most crucial symptom of hamstring strain is a pain in the muscle, which may start suddenly during exercise.
In these cases, the muscle usually swells a few hours after the injury, and the skin may be bruised, which will increase in the coming days.
When the hamstring muscles are stretched, the athlete feels that the strength of these muscles has decreased, and the range of motion may also decrease.
So, the main symptoms of hamstring muscles injuries are as follows:
- Severe pain in the back of the thigh that stops the activity.
- Swelling in the back of the thigh a few hours after the injury
- Bruises on the back of the thigh and the back of the knee
- Weakness in hamstring muscles
Factors Causing Hamstring Muscle Damage
Several essential factors cause damage to the hamstring muscles; these factors include:
1) stiffness and dryness of the muscle (lack of flexibility)
2) Hamstring muscle weakness
3) Improper warming up or lack of proper muscle stretching before starting the workout
4) Imbalance between the strength of hamstring muscles and quadriceps muscles
5) Existence of the previous injury
6) Muscle fatigue
7) Old age
8) Type of sports activity (doing heavy and stressful sports such as football, basketball, running)
9) Working a lot of muscle overuse
10) Adolescent age
During puberty, a person’s bones may grow faster than muscles. This genetic factor causes the muscles to be a little shorter than the bones, and as a result, they are under tension.
This tension increases the possibility of muscle tension damage in this age group.
Diagnosis of Hamstring Injury
After taking the history and examination of the patient, the following imaging methods can be used:
- X-ray: With the help of a simple X-ray, Ischial tuberosity (detachment of a piece from the bone along with the hamstring tendon) can be detected.
- MRI: MRI can show a good picture of soft tissues like muscles. As a result, it can help to confirm the diagnosis of a hamstring injury and its severity.
Treatment of Hamstring Injury
Treating mild hamstring injuries, such as strains that did not lead to muscle tearing, is usually non-surgical. Non-surgical treatments include:
- Rest: sports activities should be avoided, and crutches should be used to prevent putting weight on the injured limb.
- Cold compresses: Cold compresses several times a day for 20 minutes each time help to reduce inflammation and pain.
- Bandaging: Using bandaging prevents further swelling.
- Raising the lower limb: it is better to place the lower limb higher than the body (above the heart level) while resting.
- Physiotherapy: Physiotherapy can help increase the strength of the hamstring muscles and return the normal range of motion to the patient.
Surgical treatment
Surgical treatment is usually performed in cases of complete rupture of the hamstring muscles or the case of a blunt fracture of the joint of the hamstring tendon with the bone.
In hamstring fracture surgery, the muscle is stretched to its natural location, and the scar tissue created at the injury site is removed. Then the tendon is connected to its natural place on the bone with the help of special stitches.