Hamstring Strains: Article Review & Application

By Tom Sutton, DPT Student

Before the 2016 Summer Olympics in Rio began, there was some speculation as to whether or not Usain Bolt would make an appearance in the Games. Reports had come out saying that he had sustained a grade I hamstring muscle strain during the Olympic Trials. Fortunately, injuries such as this are the most mild of hamstring strains and are very treatable in physical therapy. A hamstring strain is a common injury from activities such as sprinting because for better performance in sport, the hamstrings require power and increased activation. However, there are ways to prevent and rehabilitate this injury, which a physical therapist can help with. In a study by Valle et al, the investigators evaluate rehabilitation essentials for two different types of hamstring strain injuries.

Hamstring Muscle Injuries, a Rehabilitation Protocol PurposeBy Xavier Valle, Johannes I.Tol, Bruce Hamilton, Gil Rodas, Peter Malliaras, Nikos Malliaropoulos, Vicenc Rizo, Marcel Moreno, and Jaume Jardi

Hamstring strains can be classified as two different types when it comes to the mechanism of injury: sprinting or stretching injuries. Stretching injuries have been seen to have a higher time loss than sprinting injuries and involves movements of the lower extremity with the hip flexed and the knee extended.(3) The stretching injury is mostly located at the proximal attachment of the semimembranosus muscle.(3) As for the sprinting type of injury, it mostly involves the biceps femoris long head and the time it takes the athlete or patient to return to activities is shorter in relation to stretching.(2) This type of hamstring injury can become the focus of a physical therapist to analyze and evaluate the mechanics of a patient or athlete’s running. For example, the hamstrings play a huge role in the running cycle, with muscle activation peaking during terminal swing and early stance phases.(4) The therapist will also know to address hamstring pain, muscle length with stretching, strength and control during rehabilitation because if the patient wants to return to running, power will increase with speed.(4)

Addressing a hamstring strain will involve key physical therapy principles involving normalizing the patient’s muscle length, strengthening the muscles of the lower extremity through functional exercises and neuromuscular re-education for improved coordination of the hip and knee. Injuries have protocols and rehabilitative guidelines that can give the young clinician an idea of how a patient can progress, so minding the patient’s stage of condition and tissue reactivity is important before beginning an exercise program. One interesting point made in Valle et al’s study is the concept of elongation stress on hamstrings (ESH). This can be applied clinically by subtracting the knee flexion angle from the hip flexion angle by evaluating hamstring muscle stretch during functional activities. If the ESH is larger, then there is higher stress placed on the hamstrings. A therapist can apply ESH to the running cycle by knowing that the hip ROM goes from 70 degrees of flexion to 45 degrees extension and the knee ROM goes from 30-130 degrees of flexion.

In closing, addressing the patient holistically is the approach to take. Functional exercise programs that involve the entire body as opposed to just the hamstrings will probably benefit the patient more (Examples shown below in video). One of the more common pillars of exercise treatment include core muscle activation/strengthening due to the influence of lumbo-pelvic muscles during activities such as running.(1) With this, the therapist can address things such as anterior or posterior pelvic tilt, core muscle activation and education to maintain neutral spine during exercise and activities. Additionally, there is published work in recent literature stating that neuromuscular training which includes balance training and stability can decrease the risk of lower extremity and hamstring injuries specifically.(5) Knowing the patient’s mechanism of injury, presentation and impairments will help the clinician to apply the knowledge from this study properly and design an exercise program suitable for their patient.

For more information on Valle et al’s suggestions for examination, diagnosis and treatment, please visit this link here (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4691307/)

Below are some sample exercises, the key is to apply an appropriate load to healing tissues, ranging from isolated isometrics to closed chain, multi joint, multi plane complex movements.  

1.  Hamstring Curl with BFR- Light load, tissue specific, no muscle breakdown and Growth Hormone release to promote collagen synthesis.
2. Supine Dolly Curls- Bilateral sagittal plane loading with a focus on simultaneous eccentric hip flexion and knee extension.
3. Single Leg TRX Squat- Assisted single leg sagittal plane deep squat loading without a balance challenge.
4. Barbell Side Lunge- Asymmetrical frontal plane loading, hip mobility and tissue stretching with balance.
5. Traveling Lunge + Anterior Medial Reach- Multi plane functional application of the hamstrings in eccentric and concentric closed chain loading.

 This blog post was written by Tom Sutton, DPT during his final internship with me at Catz Physical Therapy Institute as a DPT Student.  You can find Tom here @twsutt

References

1. Valle X, L.Tol J, Hamilton B, et al. Hamstring muscle injuries, a rehabilitation protocol purpose. 2015;6(4). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4691307/. Accessed March 23, 2017.
2. Askling CM, Malliaropoulos N, Karlsson J. High-speed running type or stretching-type of hamstring injuries makes a di erence to treatment and prognosis. Br J Sports Med. 2012;46(2):86–7.
3. Askling C, Saartok T, Thorstensson A. Type of acute hamstring strain a ects  exibility, strength, and time to return to pre-inju- ry level. Br J Sports Med. 2006;40(1):40–4.
4. Chumanov ES, Heiderscheit BC, Thelen DG. Hamstring musculo- tendon dynamics during stance and swing phases of high-speed running. Med Sci Sports Exerc. 2011;43(3):525–32.
5. Hubscher M, Refshauge KM. Neuromuscular training strategies for preventing lower limb injuries: what’s new and what are the practical implications of what we already know? Br J Sports Med. 2013;47(15):939–40.

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