Hamstring Injuries

A hamstring injury occurs when 1 or more of the 3 hamstring muscles or tendons (a type of soft tissue connecting the muscle to the bone) tear. It is 1 of the most common injuries of the lower body, particularly affecting athletes participating in sports such as football, soccer, or track. After tearing a hamstring muscle, a person is 2 to 6 times more likely to suffer a subsequent injury. Surgery is required to treat the most severe cases. However, in most cases, hamstring injuries are managed with physical therapy.

What is a Hamstring Injury?

The hamstrings make up the primary muscle group responsible for straightening (extending) the hip and bending (flexing) the knee. It includes a group of 3 muscles along the back of the thigh that connect the pelvis to the leg. The three muscles are the:

  • Semitendinosus
  • Semimembranosus
  • Biceps femoris
Hamstring Injuries Diagram

Hamstring injuries occur when excessive force is placed across the muscles. This typically happens during sudden starts or stops when running, a rapid change of direction with “cutting” or jumping maneuvers, or when the muscle is overstretched by activities such as sprinting, hurdling, kicking, or heavy lifting.

The common structures involved in hamstring injuries are:

  • Hamstring muscle(s) and/or tendon (a type of soft tissue that connects muscle to bone)
  • Bursa (a fluid-filled sack that sits between bones and soft tissues to limit friction), usually irritated with recurring hamstring injuries
  • Ischial tuberosity (the “sit-bone”), which in rare cases can be fractured by traumatic injury

Risk factors for hamstring injuries include:

  • A history of prior hamstring injury
  • Muscle imbalances (particularly hamstring weakness)
  • Poor flexibility (muscle tightness)
  • Inadequate warm-up before activity
  • Muscle fatigue

How Does a Hamstring Tear Feel?

When a person injures a hamstring muscle, the symptoms are related to the severity of the injury. Mild hamstring strains often just feel like a pulled or cramping muscle; you might not even realize you have pulled your hamstring until you stop performing the activity, or until the next day, when you might have soreness, tightness, or bruising. However, more involved injuries can be painful, and your symptoms might include:

  • A sudden, sharp pain in the buttocks or back of the thigh
  • A feeling of a “pop” or tearing in the muscle
  • Bruising within hours or days after the injury
  • Swelling
  • Tenderness to touch
  • Difficulty sitting comfortably, lifting the leg when lying down, or straightening the knee
  • Difficulty walking, resulting in a limp

How Is a Hamstring Tear Diagnosed?

Diagnosis of hamstring injuries starts with a thorough understanding of your health history and the cause of the injury. The questions your therapist may ask include:

  • If you have had a similar injury before
  • What you were doing when you first felt the pain
  • Where you felt the pain, and if you felt a “pop”
  • If you noticed any swelling or bruising in the first 24 hours after the injury
  • What you were able to do immediately following the injury, and how you have been functioning since the injury (walking, sleeping, lifting your leg, etc.)

Your physical therapist will also perform a clinical evaluation, including some of the following observations and tests to determine the nature of your injury:

  • Observation: To note any discoloration or bruising
  • Pain: To identify your current pain level, and the activities that make your pain better or worse
  • Palpation: To pinpoint the location and size of the tender area through touch, which will help determine the severity of the injury
  • Range of motion: To compare the motion of your injured leg with your healthy leg
  • Muscle strength: To determine the strength of the hamstring muscles when bending or straightening your knee and hip
  • Gait analysis: To note any limping or pain when walking

Typically, hamstring injuries are classified as Grade I – III depending on the severity of the injury.

  • Grade I: Mild strain with minimal tearing; usually feels like a pulled or cramping muscle
  • Grade II: Moderate strain with partial tearing; may cause a stinging or burning sensation at the back of the thigh
  • Grade III: A severe, complete muscle tear; may result in a “lump” on the back of the thigh where the muscle has torn

If your physical therapist suspects a severe injury, you will likely be referred to an orthopedic physician for medical diagnostic imaging, including x-ray and MRI, to evaluate the extent of the injury. In the event of a fracture of the ischial tuberosity (sit-bone) and/or a complete rupture of the muscle, surgery might be recommended.

How Can a Physical Therapist Help Treat a Hamstring Injury?

Your physical therapist will design an individualized treatment program specific to the exact nature of your injury and your goals.

The First 24-48 hours

Physical therapy may include:

  • Resting the injured area by avoiding aggravating activities, such as walking or working out. If you are having notable difficulty walking, crutches may be recommended.
  • Applying ice to the injured area 3-4x/day for 15-20 minutes (with a towel placed between your skin and the ice).
  • Applying a compression wrap to the area to aid in decreasing swelling and pain.
  • Referral to another health care provider for further diagnostic testing (if needed).

Range of motion
It is common for muscles and joints to become stiff after an injury. As your pain decreases, your physical therapist will begin gentle flexibility exercises, such as stretching your hamstring muscles.
Muscle strength
Hamstring strengthening will be an essential part of your rehabilitation program. Your physical therapist will compare the strength of the muscle groups in each leg, and prescribe specific exercises to target areas of weakness.
Manual therapy
Many physical therapists are trained in hands-on “manual” therapy to move and manipulate muscles and joints to improve motion, flexibility, and strength. These techniques can target areas that are difficult to treat on your own.
Functional training
As you regain the flexibility and strength in your hamstrings, it will be important to teach your body how to move so you no longer put excessive stress on the previously injured area. Your physical therapist will develop a functional training program specific to your desired activity.

In the event that the severity of your hamstring injury requires surgical treatment, a physical therapist will guide your postoperative rehabilitation. Your physical therapist will communicate with your surgeon to ensure complete and consistent postoperative care.

Can a Hamstring Tear be Prevented?

You can decrease your risk of a hamstring injury in the following ways:

  • Always warm up before participating in athletic activities.
  • Avoid starting a new activity too quickly; gradually increase the frequency and intensity of the activity so that your body may adapt to the new movement patterns.
  • Listen to your body after you work out (and stretch, apply ice, rest as needed) prior to engaging in the same routine again.
  • Use proper lifting and squatting techniques, particularly when maneuvering heavy objects.

References:

http://www.moveforwardpt.com/SymptomsConditionsDetail.aspx?cid=80e9658c-55f0-4225-814a-184a70e2a794#.VZmST_lViko