Hamstring Injuries in Distance Runners: Hamstring Tendonopathy
Proximal Hamstring tendonopathy is inflammation and degeneration of the hamstring tendon as it attaches to the Ischial Tuberosity (sit bones). It can follow a tear of the hamstring tendon that is improperly rehabiltated, or more often is an overuse injury. The hamstrings consist of three muscles (semimembranosus, semitendinosus and biceps femoris– see diagram below) which have a common origin on the sit bones. They span the back of the thigh, and assist with hip extension (increasing stride length) and controlling the lower leg as the knee extends before foot strike in running.
SYMPTOMS : High hamstring tendonopathy is an overuse injury most often seen in middle- and long-distance runnersThe condition tends to become quite painful, and often debilitating if left untreated. The athlete will typically complain of a deep buttock or upper hamstring pain brought on during acceleration and at faster speeds of running. Some will complain of sciatic and buttock pain while seated, or with bending forwards towards the toes.
The pain of hamstring tendonopathy, like other tendon problems will generally warm up with activity, and worsen again once activity is ceased, and often gives significant pain and stiffness the following morning after activity.
DIAGNOSIS: Diagnosis is made on a combination of the above signs and symptoms, and also with Ultrasound +/- an MRI. Ultrasound is useful in showing the integrity of the tendon, and how much degeneration is present, and also shows the presence of increased vascularity (blood vessels) in the tendon which occur when the injury is left untreated.
- Repetitive High hamstring load, i.e distance running, hockey, football
- Previous history of hamstring tear or injury, especially if poorly rehabilitated
- Reduced hip range of motion (especially tight hip flexors/ quads, which puts constant increased load on the hamstrings
- Reduced ankle range of motion
- Poor Core stability
- Predisposition to tendon problems, often occurs with autoimmune dysfunction such as coeliac disease, ankylosing spoldyitis (inflammation of the spine) heamochromatosis
TREATMENT: Tendons have a very poor blood supply and cellular turnover, and so generally rehabilitation takes place over months, rather than days or weeks. The primary goal is to modify load to allow the tendon to heal, and this is generally done with a goal to keep the pain at less than 2-3/10 in severity, both during and after activity.
High tendon load activities (running, jumping) should initially only be allowed every 3 days, as the tendon cells are slow to respond to load, and need adequate recovery so that the cells to not continue to break down.
Correcting predisposing factor such as core stability, weakness in the hamstrings and glutes, restricted hip and ankle range of motion, and lower back tightness must take place before reintroducing high loads and running volumes. A strict hamstring and glute strengthening program must be adhered to, to allow the tendon to be unloaded and to cope with return to higher training volumes.
Autologous Blood or Plasma injections are also often very helpful in pain reduction and stimulating healing. Shock Wave Therapy (high intensity ultrasound) is also widely used to stimulate tendon repair.