Hamstring strains are one of the leading sports injuries seen in running sports (e.g. football, basketball). In professional Australian Rules Football (AFL), hamstring strains are the most common injury (6.3 new injuries per club) which lead to an average of 25.2 lost games per club. Increasing age and previous hamstring injuries increases the risk of sustaining a hamstring strain.
While hamstring strain injuries are not severe in nature, they can become a recurring problem. The first month after recovering from the injury is the highest risk for hamstring strain re-injury. Research has indicated that the chances of sustaining another hamstring strain can be as high as 63%. 
What is a Hamstring Strain?
Hamstring strains are overstretching injuries to one or more of the muscles located at the back of the thigh. These muscles primarily help the knees bend and hips extend. Strains vary from muscle fibres being overstretched to fully ruptured depending on the grading.
Hamstring injuries are more commonly seen in sports that involve high speed, powerful movements and sudden changes of direction, such as football, tennis, or soccer.
A muscle strain can be acute (sudden onset) or can be chronic (developing over time). Increasing age and previous hamstring injuries and strains can increase the chance of sustaining another. Strength-based exercise and sport-specific training can help in the prevention of hamstring injuries.
What are the symptoms of a hamstring strain?
The symptoms of hamstring strains include pain in the back of your thigh, with weakness of the muscle, particularly noticeable when bending or straightening the leg. People may also experience swelling and tenderness at the back of the thigh.
Hamstring strains are categorised based on their severity, pain, weakness, and loss of motion.
Common symptoms of hamstring strains
Grade 1: (Mild) - Only a few muscle fibres are damaged and it does not primarily affect the muscle’s power or endurance.
Grade 2: (Moderate) - Approximately 50% of the muscle fibres are damaged or torn.
Grade 3: (Severe) - 50% to complete tear of muscle fibres. Both the muscle and the tendon can be affected at this stage.
Almost 35% of athletes who have had a hamstring strain have recurrent hamstring injuries during their career.
What causes a hamstring strain?
Hamstring strains generally occur when the muscle is overloaded beyond its capacity; this frequently happens when running. Either the hamstring is stretched too far, or the hamstring is put under too much pressure when contracting.
Most strains occur during an eccentric contraction, where your hamstring muscle contracts, while lengthening (like in a deadlift or running). During a sprint, your body weight puts a lot of load on your hamstring muscles while in a lengthened contraction, which puts a large amount of stress on the hamstring.
Hamstring injuries can also develop chronically, where the muscles are gradually overstressed over time, without adequate time to recover. Injuries to the hamstring often take a long time to rehabilitate, and there is a high incidence of recurrent injury.
Common causes of hamstring strains
There are multiple factors as potential causes of a hamstring strain. No matter what the situation, it is best to get your injury assessed by a professional as soon as possible to minimise recovery time.
Risk factors for hamstring strains
The risk factors for developing a hamstring strain include factors such as:
Previous hamstring injury
Multidirectional sports, such as soccer, hockey, football
Muscle weakness, especially hip and gluteal muscles
Lack of a warm-up before sport.
How is a hamstring strain diagnosed?
Hamstring strain can limit your mobility and prevent you from participating in sports. Additionally, staying inactive for a few weeks due to this injury may compromise your muscle performance and total body function.
There are several options available when it comes to diagnosing your leg pain as a hamstring strain. One of the more common and most recommended by Australian GPs is an assessment from a physiotherapist.
Physiotherapists are highly specialised medical professionals that diagnose and deal with pain and injuries such as hamstring strain. A physiotherapy assessment is simple yet comprehensive.
Like visiting a GP, your assessment will start with your physiotherapist asking you vital questions about your health, this is referred to as a consultation. Your consultation will last for about 30 to 60 minutes. Take this time to discuss relevant issues relating to your hamstring strain.
After establishing the background of your condition, your physiotherapist will perform specific physical tests to determine the best possible cause of your pain and rule out other conditions.
Following your initial assessment, your physiotherapist will provide you with a tailored treatment plan based on your condition.
From here, your physiotherapist will give you the details of your treatment program that may include:
Number of treatment sessions
List of exercises you need to do at home
Strategies to manage the pain and to prevent worsening of the condition
Timeline of recovery.
How is a hamstring strain treated?
Hamstring strain can affect your routine and participation in sports. In fact, almost ⅓ of athletes worldwide experience recurring hamstring injuries due to a hamstring strain.
There are several options when it comes to treating a hamstring strain. One of the more common, and the treatment option that is referred by Australian GPs the most, is physiotherapy.
Hamstring strain is an injury that physiotherapists come across regularly, and the process of treating it is straightforward. Following an initial consultation, the physiotherapist will be in the best position to determine your treatment plan.
A combination of manual therapy, modalities, and specific movement exercises will be given to you by your physiotherapist. Physiotherapists are experts in dealing with pain and musculoskeletal conditions.
Depending on the severity of your hamstring strain, a physio may provide you with a combination of the following types of treatments:
Therapeutic Exercises - Specific exercises tailored to helping rebuild strength after a hamstring strain.
Manual Therapy - Hands-on physiotherapy, helpful in reducing muscle spasms.
Stretching Exercises - Stretching can reduce pain and muscle tension whilst increasing range of motion.
Soft Tissue Mobilisation - Specific joint mobilisations are used to reduce stiffness.
Dry Needling - Using dry needling can reduce muscle spasm and aid in recovery.
Heat Therapy - Heat has been shown to increase blood flow and help the healing process.
Progressive Resistance Exercises: - As your recovery progresses, you will advance through different stages of rehab exercises.
A typical physiotherapy session with your local physiotherapist will last anywhere between 30-60 minutes, and it is not uncommon for patients to feel the benefits in just one session.
Next Step - Creating a treatment plan made for you
Following your initial appointment, your physiotherapist will craft a tailored treatment plan that will highlight the course of action required. This will include what exercises you need to do at home and provide you with a timeline for how long it should take for a full recovery.
Self-care for a hamstring strain
Whilst a physiotherapist is the number one choice when it comes to treatment of a hamstring strain, there are still things that you can do to help improve your recovery.
If you think you have a hamstring strain, here are the best things you can do and avoid.
Top things to do:
A cold compress will help minimise the swelling and control the inflammation around the site of injury. Apply for 10 to 15 minutes every 2 hours.
Muscle tears take a few weeks to recover. Tone down your activities and avoid things that would put additional stress on your hamstring.
Elevate your leg on a pillow when you sleep at night. This will help decrease the swelling on your legs and thigh.
Recovering from a muscle injury requires tons of nutrition to support the healing process. Consider incorporating lots of protein in your diet to enhance your body’s natural tissue repairing process and muscle building.
Things to avoid:
- Avoid activities that worsen the pain.
Ensure you have sufficient rest and consult a physiotherapist as soon as possible. Reduce high impact activities for at least a couple of weeks or as stated by your physiotherapist.
Do I need a specialist or surgery?
Surgeries are performed in severe cases with a complete tear of the hamstring tendon from the bone or muscle.
Diagnostic imaging may be done, such as an ultrasound or MRI, to identify the exact location and degree of your injury. Your doctor may also do an X-ray to check for avulsion fractures of the pelvis.
Surgeons will coordinate with your physiotherapist to create a plan of treatment for your recovery after the surgery. This would allow you to improve your overall health status and return to function.
What is the recovery time / prognosis for a hamstring strain?
Ultimately, recovery time is dependent on your proactiveness to seek professional treatment and the severity of your pain and injury.
Most strains and partial tears typically recover between 4-8 weeks. Physical therapy is most crucial to prevent secondary complications and maintain optimal strength and function during this time.
A complete tear can heal in 3 months and might take longer if surgery is required.
Physiotherapy is an essential part of recovery from a hamstring strain. Through exercise protocols and treatment interventions, you can speed up the recovery process and build more robust and more durable musculoskeletal structures to tolerate your activities and lifestyle.
Can a hamstring strain be prevented?
Guaranteeing prevention can be impossible; however, you can decrease the risk of hamstring strains through some of these techniques.
Improving your flexibility - Stretching your lower body muscles will increase your range of motion and prevent injuries associated with a muscle strain.
Increasing your muscle strength - Proper control and stability of your hamstring muscle will allow it to tolerate high amounts of stress. Additionally, strengthening your overall lower body and core muscles will help you prevent injuries.
Avoiding overtraining / over fatigue - Overtraining increases your body’s stress beyond its capacity. This puts unnecessary risks to your joints and muscles due to wear and tear factors.
Warming up - Always prepare your body before engaging in high-demanding tasks.
Outlook and the main takeaways
Hamstring injuries are common, especially in athletes. They are complex to treat and have a high incidence of recurrence.
If you have a hamstring strain or sprain and are still unsure what to do, remember that pain is a signal to your body to take action. Have your injury assessed by a physiotherapist as soon as possible so that you can accelerate your recovery, and get back to doing what you love!
Anatomy of the hamstring region
The hamstrings are groups of muscles located at the back part of the upper leg.
It is composed of three different muscles that primarily act to bend (flex) the knee and straighten (extend) the hip.
Biceps femoris: The biceps femoris has two parts, called ‘heads’ – the long head, and the short head. The biceps femoris sits on the lateral (outer) side of the hamstrings.
Semitendinosus: Semitendinosus is a long muscle that sits on the medial (inner) side of the hamstrings.
Semimembranosus: Semimembranosus is a wider and flatter muscle, and sits on the medial side of the hamstrings nestled underneath semitendinosus.
The lower part of these muscles are attached to the tibia and fibula below the knee, while the upper part attaches to the bottom part of the pelvis.