Hamstring Strain Rehabilitation

What is a hamstring injury?

A hamstring muscle strain is a common sports injury at the high school, collegiate, and professional levels. Participants in track, football, baseball, soccer, and rugby are especially prone to this injury given the sprinting demands of these sports.

When it comes to hamstring strains, two things are certain:

1. They are super common in athletes, with research showing that almost 30% of all lower extremity sports injuries are hamstring injuries. In NFL football players, the occurrence of hamstring strain injuries is second, only to knee sprains.
2. The recurrence rate is high, with research showing up to a 30% recurrence rate for hamstring injuries. This is evidence that athletes are rushing back to sport too soon, that return to sport criteria is not adequately met, or these hamstring strains are not being rehabilitated well.

How does a hamstring strain happen?

A majority of hamstring strain injuries occur during high-speed running. During the second half of the swing, the hamstrings are active, lengthening and absorbing energy from the decelerating limb preparing for foot contact. Running-related hamstring strain injuries typically occur along an intramuscular tendon, aponeurosis, and the adjacent muscle fibers.

Another common way athletes injure their hamstring is with slow or fast movements that involve simultaneous hip flexion and knee extension, placing the hamstrings in a position of extreme stretch, with injuries most commonly presenting in the semimembranosus and its proximal free tendon.

How to treat a hamstring injury?

1. Avoid stretching 
One of the easiest things you can do acutely following a hamstring strain is to avoid stretching. People load the hamstring tissue way too early. Often people tend to stretch through this pain and discomfort, thinking that if they get “looser,” it will feel better.

Over-stretching too early is just going to delay the healing process. This, unfortunately, happens all too often in the rehabilitation setting and the athlete themselves as they constantly want to stretch or “test” the area throughout the day.

Some gentle range of motion is encouraged in the acute phase, but we don’t want to stretch the tissue just damaged by an overstretch type of injury.

It makes sense not to stress a tissue that has just been torn. By taking a step back in this acute phase and refraining from stretching, you are putting the tissue in a position to succeed in the future phases of rehab when we need to start applying more load for proper healing.

2. Leave eccentric exercises out of the picture

It has been theorized that hamstring strains are common due to the large amounts of eccentric contractions observed during the swing phase of running/walking as the hip flexes and the knee extends outward. It makes sense that hamstring strain rehabilitation and prevention programs that emphasize eccentric hamstring exercises tend to have better results.

After a hamstring strain, it has been demonstrated that eccentric hamstring strength is impaired.
The common belief is that there is a change in the force-length relationship of the hamstring after an injury, resulting in peak force at a shorter length. But, eccentric training can shift this relationship and allows peak force at a longer length. These results emphasize the importance of including eccentric exercises during hamstring rehabilitation.

3. Dynamic hamstring exercises

It’s one thing to perform a simple and slow eccentric contraction exercise, and another to perform a dynamic and explosive contraction that mimics the specific movements the athlete performs. At Performance Physical Therapy, we often use lower body plyometrics for this. It allows both a rapid eccentric contraction followed by an explosive concentric contraction.

When can I return to sport after a hamstring injury?

This is the great debate, when do we return the athlete to their sport? Several studies show that many athletes return to sport too quickly, allowing signs of residual loss of hamstring strength, weakened scar tissue, poor mobility, and imbalances. A rush back to full activity can occur as pain is abolished before the hamstring has regained its full tensile strength throughout the full range of motion and certain risk factors can easily be overlooked.

The risk factors that contribute to the high rate of hamstring re-injury include the following :

1. Persistent weakness in the injured muscle
2. Reduced extensibility of the musculotendon unit due to residual scar tissue, and
3. Adaptive changes in the biomechanics and motor patterns of sporting movements following the original injury.

Unfortunately, part of the problem is that proper return to sport criteria is rarely used to determine if an athlete is ready to return to sport. A rehabilitation approach focused on objective criteria to progress in the healing process is vital, instead of merely basing a return to activity on pain-free function alone. In our return to sport hamstring protocol, there are 3 specific phases of progression.

An athlete cannot progress to the next phase until specific criteria are met, demonstrating the hamstring’s readiness to accept the load.

• Phase 1 focuses on protecting the injury site while minimizing atrophy in the hamstring.
• Phase 2 emphasizes regaining pain-free hamstring strength, beginning at mid-range and progressing to longer hamstring length. In this phase, we also focus on developing neuromuscular control of the trunk and pelvis with progressive movement speed.
• Phase 3 is where the athlete is symptom-free during all activities. Integration of dynamic sports-specific movements is incorporated to ensure the athlete is ready to return to sport.

Conclusion

We understand the difficulty of navigating a hamstring strain and getting the athlete back to the field quickly and safely. We are here to answer questions as you wade through the waters of this frustrating injury. The knowledge to skillfully heal a strained hamstring is vital, and all physical therapist at Performance Physical Therapy are trained at the highest levels of the orthopedic specialty. Our team will properly diagnose and treat the hamstring strain through our proven 3 phase approach.

Contact us (302-599-0029) to help you get to the root of your pain.