Managing Hamstring Strains: Early Rehabilitation

Hamstring strains remain one of the most common and frustrating injuries for athletes and active individuals. This injury is often recognised for its significant re-injury rate, adding to the frustration of athletes, coaches, and medical professionals involved in their management. Hamstring strains typically occur suddenly during high-intensity activities like sprinting, commonly affecting those participating in sports that require repetitive sprinting, jumping, and/or kicking. The sudden onset of pain and subsequent limitations can be a significant setback, disrupting training and competition schedules. This limitation in athletic performance, coupled with a high re-injury rate, makes a thorough rehabilitation program critical to mitigating the future risk of injury and ensuring a timely return to training and competition.

Understanding Hamstring Injuries

The hamstring muscles, located at the back of the thigh, consist of three primary muscles: the biceps femoris, semitendinosus, and semimembranosus as seen in Figure 1 below. These muscles play a vital role in activities involving leg movement, such as running, jumping, and kicking. Unfortunately, they are also susceptible to injury due to their involvement in high-intensity movements, especially high speed running.

Hamstring injuries are generally categorised into three grades:

1. Grade 1: Mild strain with minimal fiber damage and discomfort.

2. Grade 2: Moderate strain with partial tearing of muscle fibers, resulting in pain, weakness, and limited mobility.

3. Grade 3: Severe strain or complete tear, causing intense pain, significant loss of function, and difficulty walking or bearing weight

It's also worth mentioning that subcategories exist within these grades which are likely to influence return to play times and re-injury risk. This can be useful in individuals participating at a high level of sport where it's critical to minimise games or events missed due to injury. These subtleties can be identified with an MRI scan, and with this information at hand, your sports physio can adjust your rehab program accordingly.

Figure 1: The Hamstring Muscles

Key Rehabilitation Stages

Sports physiotherapy plays an important role in the recovery process of hamstring injuries, providing guidance through each phase of rehab to allow a safe return to competition. A rehabilitation plan from a hamstring strain can be structured into the following phases:

1. Early Stage - Early Injury Management: The early phase after a hamstring injury focuses on preventing further damage and promoting healing. Rest from activities that strain the hamstring is crucial to protect the injured muscle and allow the early healing process to occur. Under the guidance of a sports physiotherapist, early resistance training targeting the injured muscle can encourage quicker recovery of muscle function. As pain subsides and function begins to return, a structured rehabilitation program that includes gym-based exercises and a graded progression of low-speed running is essential to fully restore the muscle’s capacity.

2. Middle Stage - Restoration of Muscle Capacity & Return to High Speed Running: During the middle stage, the goal is to regain sufficient strength and endurance in the hamstring muscles to safely start and accumulate high-speed running. Speeds will be gradually increased, and agility drills can be incorporated if they are relevant to your sport. Additionally, there should be repeated, graded exposure to the original injury mechanism, such as kicking or bending, if it differs from sprinting.

3. Late Stage - Return to Training & Competition: Following a solid block of training involving high speed running, agility (if required), and exposure to the original injury mechanism, athletes should be introduced to high intensity sports/activity-specific drills before returning to unrestricted competition.

4. Prevention Strategies: Hamstring injuries are often the result of errors in training load prescription and may also be contributed to by underlying strength deficiencies, biomechanical imbalances or faulty movement patterns. It's important to have a thorough assessment in each of these areas to identify any contributing factors. By addressing these factors you can reduce the risk of re-injury. Ensuring proper warm-up exercises, resisted exercises to maintain muscle strength and appropriate training loads can also help minimise the risk of hamstring injury recurrences.

Early Stage - Early Injury Management

Immediately following a hamstring strain injury, rest is important to protect the muscle from further injury. Once this acute phase has passed, usually one to three days post-injury, it's good practice to start early stage strength exercises. The timing, type and intensity of these exercises will vary depending on each individual injury and should be guided by a sports physiotherapist. As a general guide however, the following should be considered:

1. Knee Dominant Hamstring Strength: The hamstrings cross both the hip and the knee joint, therefore they are used to generate movement at the hip and knee. An example of a knee dominant exercise would be a prone hamstring curl, as pictured below. Nordic drops and hamstring sliders are other common hip-dominant hamstring exercises.

2. Hip Dominant Hamstring Strength: This could be a hamstring bridge, also pictured below. Romanian deadlift and 45-degree hip extension are other common hip-dominant hamstring exercises

3. Range of Motion: Although some strengthening exercises will encourage full range of motion through the hamstring, targeted hamstring stretches can be indicated if there is a loss of flexibility following injury.

Not only is early strengthening safe when programmed appropriately, but it is also thought to result in an earlier recovery of your hamstring strength which could have implications on your return to play time and risk of re-injury.

The Single Leg Hamstring Bridge: Start with your hips flat on the floor with your heel up on a box (higher box = harder). Pull down through your heel keeping a slight bend in your knee and lift your hips up towards the ceiling.

The Prone Hamstring Curl: Start with a slight flex in your knee, pull your heel up towards your bottom as far as possible. Slowly lower the weight back down to the start position.

Return to low speed running

Returning to running is a significant milestone as it represents the first clear step back to training and competition. Once adequate range of motion and strength has been recovered, low speed running at a comfortable jogging pace can start. This can sometimes be as early as 2-3 days post-injury, but will be dependant on your specific presentation and should guided by a sports physio. The following benchmarks should be aimed for:

• Hamstring Flexibility/Range of Motion: Restoration of hamstring flexibility to within 10-15% of the non-injured side. This can be accurately measured by a sports physiotherapist.

• Hamstring Strength: Able to complete at least 10 single leg hamstring bridges, as seen in the picture above, through full range of motion. This is a good basic indication of sufficient strength to cope with a light jog. Another useful test, although less accessible, is an assessment of knee flexion torque. This can be measured directly using a device called a dynamometer. Knee flexion force is measured by the dynamometer, then is converted to a standardised measure of newton-meters per kilogram of bodyweight (nm/kg) to account for the different bodyweight and limb lengths of each individual. From kinetic studies of running and sprinting, It's thought that low speed running demands less than 1 nm/km of knee flexor torque, therefore this is a good starting point.

Middle Stage - Restoration of Muscle Capacity & Return to High Speed Running

Working with a sports physio to determine when you’re ready to start hamstring strength exercises and light running is an important part of your rehab plan. These decisions can affect how long you spend on the sidelines and influence your risk of re-injury. Once you’ve achieved these initial milestones, the next phase focuses on restoring your hamstring muscle capacity to its pre-injury level through heavy resistance training and progressively increasing the intensity of your rehab running. Stay tuned for our next blog post, where we will discuss in more detail how and why this process is essential.

If you need guidance with your hamstring rehabilitation, you can book online or call or text us at 0415 889 903 to schedule an appointment with our senior sports physiotherapist. We will create an individualised plan to help you return to competition as quickly and safely as possible.