Hamstring syndrome

General information

The definition of “hamstring” refers to the posterior thigh muscle group. This group includes the biceps, semitendinosus, and semimembranosus muscles. The muscle fibers are attached in the area of the sciatic tubercles and further down the thigh and are fixed to the inner and outer sides of the tibia. The main physiological function of this muscle group is to fix the tibia in the desired position during flexion movements in the knee joint during running, walking, and squats. In addition, the hamstring muscles are involved in the act of flexion of the tibia. 

What is hamstring syndrome?

In traumatology, hamstring syndrome is a pain syndrome with extra-articular localization. The disease was first described in 1980 as the result of chronic damage to the muscle fibers of the thigh. Modern traumatologists call hamstring syndrome a combination of degenerative and dystrophic processes that manifest themselves with painful sensations in the groin area.

Hamstring syndrome occurs in more than 60% of cases in professional athletes. There are many more male patients with this condition than female. This peculiarity is associated with intensive loads and hard physical labor.

Causes of hamstring syndrome

The mechanism of hamstring syndrome is based on systematic, intensive loads on muscles and tendons, which provoke microtraumas and fiber tears.

Among all the possible injuries, stand out:

• stretching of muscle fibers with minor tears;
• incomplete tears;
• partial or complete tears in which the muscle, which has lost its attachment to the bone, shortens and moves away from the fixation site;
• tear-off fractures, in which the contraction of a muscle leads to the tearing off of a piece of bone.

Painful manifestations of hamstring syndrome usually affect beginners or people who do not perform physical training correctly. Without the supervision of an experienced trainer, the load is distributed incorrectly, leading to injuries to muscles, ligaments, and tendons.

Another cause of hamstring syndrome is performing sports activities without first warming up. Neglecting warm-up exercises causes muscle groups to need sufficient blood flow. Without a full blood supply, in conditions of oxygen and nutrient deficiency, muscle fibers do not warm up and do not acquire proper elasticity. As a result, microtraumas occur during jogging, performing complex exercises, or training with heavy weights.

However, the development of hamstring syndrome cannot be ruled out even after preliminary muscle warm-up. The probability of overstretching and injuries, for example, of the proximal tendon of the biceps femoris muscle, is possible with intensive loads with acceleration. Such loads include running with acceleration and jumping over barriers.

In addition to sports, the following risk factors are identified that may cause the development of hamstring syndrome:

• history of thigh or lower leg muscle injuries;
• stiffness in the upper leg muscles;
• rapid leg fatigue even with minor exertion;
• insufficient stability of the muscles of the buttocks, back of the thigh, abs;
• imbalance in muscle structure – asymmetry, mismatch in the size of paired muscle fibers and groups;
• knee injuries;
• excessive flexibility of the quadriceps femoris in professional athletes;
• advanced age;
• polymorphism of some genes (IGF2 and CCL2), which is associated with a high risk of severe injuries;
• associated lumbar conditions;
• lordosis of the lumbar spine.

Symptoms of Hamstring syndrome.

Overstretching of the hamstring muscles is manifested by an attack of pain in the back of the thigh. The intensity of the pain can range from mild to extremely sharp. Patients characterize the accompanying sensation as a tearing or “popping” sensation. At the same time, there is a feeling of weakness in the affected limb.

After some time, patients feel numbness and tingling in the leg below the area of injury. External examination often visualizes edema and hematomas, the size of which can be quite extensive. Reduced mobility and decreased muscle length are detected.

There is a classification of the severity of hamstring syndrome based on the intensity of symptoms and the degree of mobility limitation:

• Grade I — mild. It is characterized by damage to a few muscle fibers or their minor rupture. Painful symptoms appear about 24 hours after the injury. Patients complain of tension on the posterior surface of the leg and slight swelling of soft tissues. The ability to move is typically preserved, and the knee joint does not lose mobility.
• II degree — medium. It is diagnosed when no more than half of the muscle fibers are torn. Patients complain of sharp pain and rapidly increasing swelling. Motor activity is reduced, and the patient has difficulty walking. Painful sensations increase when pressing on the muscles of the posterior surface of the thigh or trying to bend the knee.
• Grade III—severe. It is diagnosed when more than half of the muscle fibers or the entire muscle are torn. Examination reveals rupture of tendons. Patients experience intense pain, pronounced swelling of the injured limb, and lack of muscle tone. It is impossible to perform any leg movements.

The clinical picture of hamstring syndrome is significantly aggravated with concomitant impingement of the sciatic nerve by swollen soft tissues. A pronounced pain syndrome with impaired tactile sensitivity is noted when the sciatic nerve is involved in the process.

 Diagnosis of hamstring syndrome

An orthopedic traumatologist can conclude the presence of hamstring syndrome based on the data from diagnostic tests. To confirm the diagnosis, a comprehensive approach is required, which involves performing:

• of the initial examination;
• collection of anamnesis to obtain data on previous injuries and sports loads;
• palpation of the painful muscle area;
• ultrasound of the painful area;
• magnetic resonance imaging (MRI) of the lower extremities;
• Radiography to detect signs of damage to the sciatic tuberosity.

MRI remains the main method of differential diagnosis. The specialist clearly identifies the areas of damage, tears, and tears of ligaments, tendons, muscle fibers, swelling, hematomas, and scarring changes on the images obtained.

Treatment of hamstring syndrome

If hamstring syndrome is confirmed, the traumatologist chooses a therapeutic tactic. Conservative treatment is prescribed to control pain syndrome, relieve tissue swelling, and restore motor activity. In severe cases of complete muscle rupture, surgery is advisable. 

In cases where the patient has undergone surgical restoration of the integrity of torn muscles, rehabilitation specialists develop an individual program of restorative physiotherapy and massage complexes.

Conservative treatment of hamstring syndrome involves several measures:

• elastic bandage;
• in the first 2-3 days – applying ice to the injured area;
• immobilization of the injured leg for 7-14 days;
• prescription of non-steroidal anti-inflammatory drugs, painkillers, and plasma therapy.

Forced positioning of the limb during treatment inevitably leads to the development of complications:

• weakness in muscle tone;
• weakness in the hip joint;
• the formation of calcifications irritating the sciatic nerve;
• the onset of pain in the sitting position.

It takes about two weeks to regain full motor activity. After surgical treatment, rehabilitation can take about 7-8 weeks. Exercise is supervised by an experienced specialist, which prevents incorrect performance. The patient learns basic skills, which later help him/her warm up the muscles correctly and optimally distribute the load on the legs.

Stretching exercises occupy a special place: exercise on an exercise bike and swimming pool. They help prevent muscle overstretching and prevent the recurrence of hamstring syndrome. Therapeutic massage promotes rapid healing of damaged muscle fibers, restoring the function of tendons. One of the critical roles in treating hamstring syndrome is physiotherapy. Depending on the nature and severity of the damage, doctors apply:

• hydrotherapy;
• electrical stimulation;
• shockwave action;
• cold salt compresses;
• hydrokinesiotherapy.

The combination of all rehabilitation measures protects against re-injury of muscle fibers and tendons.

Compliance with all therapy and rehabilitation requirements ensures a favorable prognosis for the recovery of patients with hamstring syndrome. Athletes return to normal physical activity after about 1-2 months. Slower recovery is noted in thigh muscle tears. Severe forms of hamstring syndrome are dangerous, with a high probability of repeated injuries.

Surgical treatment

In acute trauma, orthopedic surgeons may offer surgical treatment for a hamstring tendon torn at the muscle or tendon part or with a bone fragment from the sciatic tubercle. In this case, the essence of surgery is to restore the integrity of the torn tendon or fix the bone fragment back to the site of the tear.

Surgical treatment is also suggested for chronic hamstring syndrome when conservative treatment is not practical. In this case, the main point of surgery is to remove the scar tissue that has formed and eliminate pressure on the sciatic nerve.

All these treatment options are available in more than 600 hospitals worldwide (https://doctor.global/results/diseases/hamstring-syndrome). For example, Hamstring syndrome surgery can be done in these countries at following approximate prices:

Turkey $2.3 K in 14 clinics

Germany $12.2 K in 35 clinics

United States $12.7 K in 15 clinics

China $19.4 K in 6 clinics

Israel $19.9 K in 13 clinics.