The hamstrings are set of muscles behind the thigh bone and behind the knee. A hamstring injury is when one of the three hamstring muscles are injured in the muscle belly or its tendon. It is one of the most common leg injuries of the lower extremity. Hamstring injuries are predominantly athletic injuries and particularly affect participants of the following sports: football, soccer, running.
The set of three hamstring muscles are comprised of the semitendinosus, semimembranosus, and the biceps femoris. These muscles are responsible for bending the knee and/or straightening the hip.
Patients are two to six times more likely to have re-injury after injuring a hamstring muscle. Most cases are managed and resolved with physical therapy, and in severe cases surgical intervention may be needed.
Hamstring injuries can occur at the following anatomical locations on the body:Muscle and hamstring injuries occur when a load is given to the muscles that it cannot handle. This may mean the amount of the force, or the acceleration of it. In the case of the hamstring muscles, injuries happen during sudden starts and stops during running, cutting maneuvers with sudden changes in direction and speed, and when a lot of strain is put on the overstretched hamstring muscles when sprinting, hurdling, kicking, or in weightlifting.
- The hamstring muscle belly and/or its tendon attachment.
- The hamstring bursa, which is a fluid-filled sac that mitigates the friction between the hamstring tendon and the bone. Chronically injured hamstrings usually present with irritation of this bursa
- The Ischial tuberosity, or the “sit bone” of the pelvis. This can get fractured in severe and sudden injuries.
Some factors may increase a patient’s risk of hamstring injury (and re-injury). They are:
- A history of previous hamstring injury
- Hamstring weakness and surrounding muscle imbalances
- Excessive hamstring tightness and inflexibility
- Poor warm up routine before intense activity
- Hamstring muscle fatigue
Signs and Symptoms of a Hamstring Tear or Injury
Symptoms can vary between hamstring injuries, and largely depend on the severity of the tear. The patient may feel a slight pull or cramping, if the injury is mild; and in some cases the patient may not feel anything at all until they have stopped performing the activity. The patient may even feel a latent effect the next morning with feelings of unusual soreness or tightness. However, sometimes hamstring injuries can be more immediate and severe. This would indicate a larger tear in the muscle or tendon, and may be more severe in its injury site. The symptoms a patient would feel in a severe hamstring tear would be:
- An immediate sharp pain felt in the buttocks or back of the thigh
- A feeling or sound of a "pop" or tear in the muscle during the injury
- Bruising in the limb within a couple of hours after the injury
- Swelling in the muscle
- The area will be tender to light touch
- Pain with sitting
- Difficulty in movement such as in lifting the leg or straightening the knee
- Difficulty and pain with walking, causing a limp in the gait.
How Are Hamstring Tears Diagnosed?
Your physical therapist will conduct a thorough subjective evaluation in the beginning of your session to properly ascertain the region of injury and the cause of it. A detailed health history,even including history of muscular strains - is precious data for the PT. The questions your physical therapist may ask you would be:
- If you have experienced a similar hamstring injury before
- What activities you were doing when you felt your pain, or if latent, what strenuous activities were you going the day before
- The location of the pain and whether you felt/heard a "pop" in the muscle
- What the aggravating and alleviating factors are in your hamstring injury (e.g. how you feel when you walk, sleep, go up and down stairs, sit, etc)
Your physical therapist will then proceed to do a clinical evaluation to get a better sense of the injury and this includes:
- Observation and palpation of the injury site to note any bruising, swelling, tenderness and degree of muscle tension.
- Range of motion measurements of the leg, with comparison to the non-injured limb, to see how severe the movement deficits are and which specific movements elicit your pain.
- Test your muscle strength to see which muscles in and around the hamstring are deficient and unstable.
- Perform a walking or running Gait analysis to see whether you are performing any compensations while running or walking that may be contributing to the hamstring injury. In our clinic we take this a step further with Video recording and playback so we can watch what every joint is doing at different phases of running or walking.
- Assess nerve involvement through range of motion maneuvers and nerve tension tests to see if the sciatic nerve (which runs through the same site as the hamstrings) is involved.
In general muscle tears and hamstring muscle injuries are graded by the following system according to severity:
- Grade I: Mild strain and minimal tearing of the muscle; the muscle will feel pulled or cramped
- Grade II: Moderate strain of the muscle with partial tearing; the muscle may feel like a stinging or burning sensation at the back of the thigh
- Grade III: Severe or complete muscle tear; the muscle may curl up into a ball or lump that can easily be felt at the back of the thigh
In in the event that your physical therapist suspects a severe injury or severe involvement of the sciatic nerve, he/she will refer you out to an orthopedic physician for further diagnostics. After the initial consultation with the ortho, they will likely perform an MRO or an X-Ray to get a more detailed picture of the severity of the tear. When a fracture of the ischial tuberosity is determined or when there is evidence of a complete tear of the hamstring, surgical intervention might be indicated.
Physical Therapy Treatment
Your physical therapist will design an individualized plan of care to treat your hamstring injury that is specific to its severity and also the nature of mechanism of injury. Judging on its severity, he/she will give you recommendations on how much to back off from activity.
Range of motion
Muscles become tight and stiff after an injury and it is necessary to maintain the length and flexibility of these muscles, or scar tissue may form that would compromise it in the long run. Prompt treatment by a physical therapist will help in minimizing the tightness and spasms. This would come in the form of soft tissue mobilization and massage, or in flexibility maneuvers and exercises.
Building Muscle Strength
Injured muscles also tend to get weak very quickly and lose their ability to handle load. Hamstring strengthening will be a part of your strengthening program in physical therapy. Additionally, there may be other exercises thrown in to your program to address weaknesses or compensations in other parts of your body that may have contributed or resulted from your hamstring injury
Functional and Sports-Specific Training
As flexibility, soft tissue health and strengthening improves in your hamstring, it is also necessary to slowly regain functionality in your sport or activity because we want to make sure that you can handle the loads that you give it during functional movements. Your physical therapist will work closely with you to mimic the sports-specific motion and progress its difficulty so we can appropriately and confidently discharge you to playing your sport again.
After Surgery Physical Therapy
If your hamstring tear warranted surgical intervention, physical therapy is a very important stage of healing. Though the process might take longer, physical therapy will allow for a gradual and progressive rehabilitative process that would get you back to full strength and ability.
Prevention of Hamstring Injuries
Hamstring injuries can be prevented in the first place. Here are some things you can do if you feel you are more prone to one:
- Never skip warm up before performing sports, proper blood flow must be encouraged before a load is given to muscles.
- Make sure you have a progression plan when beginning a new sport or activity. Gradually increase the intensity rather than jumping into full intensity sports too quickly - this would allow muscle tissue time to adapt and grow as the load and forces increase.
- Be in tune with your body - notice tightness, unusual soreness and treat it appropriately with ice, massage, rest or stretching.
- Use proper lifting biomechanics when lifting heavy weights. When in doubt, ask a physical therapist on proper posture during lifting, and we can show you how to prevent a myriad of injuries from moving the right way.
If you are experiencing pain from a hamstring pull or other leg injury, please contact one of our Portland Physical Therapy Clinics and get treated today!