The hamstring muscle is a group of large, powerful muscles that span the back of the thigh, from the lower pelvis to the back of the shin bone. The hamstring is the important muscle that functions to extend the hip joint and flex the knee joint.
The hamstring muscle is balanced by the quadriceps muscles that are located on the front of the thigh and cause the knee to extend. Together the hamstrings and the quadriceps help control power and stability of the knee joint, allowing activities like walking, running, jumping, and squatting.
What are the symptoms of a pulled hamstring?
The symptoms of a pulled hamstring depend on the severity of the injury. The hamstring injury is usually sudden and painful. Other common symptoms include:
- Bruising: Small tears within the muscle cause bleeding and subsequent bruising. The bruise begins in the back of the thigh, and as time passes the bruise will pass down below the knee and often into the foot.
- Swelling: The accumulation of blood from the hamstring injury causes swelling of the thigh. This can make further muscle contraction difficult and painful. Wearing a compressive bandage can help control the swelling.
- Spasm: Muscle spasm is a common and painful symptom of a hamstring injury. Because of the trauma to the muscle, signals of contraction are confused, and the muscle may be stimulated. If severe, muscle relaxants can help with spasms.
- Difficulty Contracting: Flexing the knee is often painful after a pulled hamstring, and can even prevent the patient from walking normally. If you are unable to contract the hamstring, the muscle may be completely ruptured.
Severity of a Hamstring Injury
Hamstring strains are classified as 1st (mild), 2nd (moderate), or 3rd (severe) degree strains depending on the extend of the muscle injury.
Mild (Grade I) Hamstring Injury
- Muscle stiffness, soreness and tightness in the back of the thigh.
- Little noticeable swelling.
- A normal walking gait and range of motion with some discomfort.
- Flexing the knee to bring the heel up
Moderate (Grade II) Hamstring Injury
- Gait will be affected-limp may be present .
- Muscle pain, sharp twinges and tightness in the back of the thigh.
- Noticeable swelling or bruising.
- Painful to the touch.
- A limited range of motion and pain when flexing the knee.
Severe (Grade III) Hamstring Injury
- Pain during rest which becomes severe with movement
- Difficulty walking without assistance.
- Noticeable swelling and bruising.
Pulled Hamstring Causes
A pulled hamstring is a common term that refers to a strain of one or more of the hamstring muscles. Muscle fibers of the hamstring can become strained or torn during running, kicking, or even walking down steps. When a hamstring muscle is pulled, the muscle fibers are abruptly stretched. Depending on the severity of the strain injury, the muscle can actually tear and many people can hear and feel an audible “pop” when the muscle is damaged.
The hamstring pull may occur anywhere along the muscle tendon anatomy, however it most commonly occurs in the middle of the hamstring muscle.
There are a variety of potential risk factors for hamstring injuries.
- Inadequate warming up and poor stretching
- Muscle weakness or an imbalance in the muscle strength within the hamstring muscles
- Muscle weakness or an imbalance between the hamstrings and quadriceps
- Poor footwear
- Recurrent injury when the muscle hasn’t completely healed from previous damage
What is the treatment of a pulled hamstring?
Treatment of a pulled hamstring is dependent on the severity of the injury. Because of bleeding and swelling, athletes should stop their activity and rest immediately. An ice pack and compressive bandage can be applied to control swelling. Crutches may be necessary if walking is painful or if spasms are severe. If the pain is significant, or if the symptoms do not steadily resolve, medical evaluation should be obtained.
Some steps to take include:
- Ice the injury
- Apply a compressive bandage
- Use crutches
- Gently stretch the hamstrings
- Massage the injured area/Seek physical therapy
Seek medical attention if:
- You have difficulty walking
- The pain is significant and not relieved with rest
- You think you may have a complete hamstring rupture