Hamstring injuries can be a big problem for runners. The hamstring plays a pivotal role in the running gait cycle and injury and re-injury rates are high.
Hamstring injury severity, age, training history, and overall injury history all factor into getting back to sport and competition. Previous hamstring strain, previous calf strain, and exposure to high-speed running also increase the risk of hamstring strain.1
If you’re dealing with a hamstring strain, here are some evidence-supported ideas to keep in mind:
The closer the pain is to your glutes, the longer it may take to heal. A study of elite sprinters showed that there was a significant correlation between the location of the point of highest pain during palpation and time back to pre-injury level at clinical examination; the closer to the “sit bone” the pain, the longer it took to get back to pre-injury levels.2 Bottom line: visit a skilled PT who can properly assess your injury severity in order to set your expectations about returning to running appropriately.
Re-injury rates are high. Re-injury rates after initial hamstring injury have been shown to be as high as 63% in the first year.3 In a study of elite sprinters with hamstring strains, function increased and pain decreased quickly, but strength and performance tested within 90% in 6 weeks – much later. Bottom line: Be careful 4-10 days post-injury when the pain gets better; the hamstring is still vulnerable to re-injury.
PT assessment can give a more accurate return-to-sport timeline than MRI: MRIs are good at detecting the location and muscles involved in a hamstring strain. In the past, athletes and clinicians have relied on MRIs to grade a muscular hamstring strain and, in turn, predict when an athlete can get back to sport. But new research challenges this. On MRI, the edema of a hamstring strain will show up as a white cluster, or with “increased fluid signal intensity.” New research supports that this increased signal intensity after hamstring injury does not delineate between a strained vs recovered hamstring.4 Bottom line: Functional testing by a skilled clinician will give a better timeline for return-to-sport decisions than MRI.
Some pain during rehab is OK: A recent study showed that participants with hamstring strains recovered in the same amount of time (15-17 days) if they were allowed to experience up to 4/10 pain vs 0/10 pain. But, notably, the “pain-threshold” group had greater recovery of muscle strength and better maintenance of hamstring fascicle length compared to the pain-free group. This suggests that when pain is not a barrier to contracting the hamstring during rehab, participants were less fearful to perform therapeutic exercises that help the muscle become more resilient after injury.5 Bottom line: Hamstring strains are an injury that will heal even if you experience a little pain during the rehab process. However, this isn’t a license to resume training as normal after a hamstring strain. A skilled PT will help monitor pain trends and will teach you self-monitoring tools as well.
The Nordic Hamstring Exercise can reduce injury risk. In a systematic review of 8459 athletes and 525 hamstring injuries, it was found that including the Nordic Hamstring Exercise (NHE) in a strength and conditioning program can reduce hamstring injury risk by 51% for all athletes competing at different levels of competition and across multiple sports.6 The NHE puts your hamstrings under the same stress experienced during running: the muscle has to stay strong under tension as your leg stretches out. Think about the running gait cycle: when your leg drives forward, your lower leg stretches out and then your foot hits the ground. When your lower leg is stretching out, your hamstring is slowing down the forward motion of the leg. This is called eccentric work of the muscle. The hamstring has to be able to stay strong under these eccentric loads, which occur over and over with running. The NHE will actually change the architecture of the muscle and it doesn’t take long, either. A study found that performing the NHE 2x/week for 4 weeks counteracts multiple hamstring injury risk factors in physically active young adults.7 Bottom line: NHE is essential to a comprehensive hamstring rehab or prevention program. It is a toughie and there are multiple modifications to best suit you. Seek a PT who can help individualize the treatment for you.
Also, not to be overlooked is an element of returning to running that will highly impact the timeline, which is the ability to “get out of your own way” and not rush the rehab process in order to return to running sooner than your healing process allows.
When an injury occurs, an athlete finds themselves at an unexpected intersection of dedication to sport, motivation for training, beliefs that drive the stress-recovery balance, and tolerance for suddenly changing plans. It’s at this intersection that an athlete uses the available information they have, mixed with their goals, beliefs, and risk tolerance, to make a choice about what’s best for them at that moment and in the long term, which are sometimes competing decisions.
The 2016 Consensus Statement on Return to Sport put it perfectly: “Instead, return to sport should be viewed as a continuum, paralleled with recovery and rehabilitation — not simply a decision taken in isolation at the end of the recovery and rehabilitation process.”8
As the statement points out, each athlete is the gatekeeper to their personal return to sport decision. A skilled physical therapist can be an ally to inform decision-making as well as provide support, context, and a listening ear along the way.
There is no magic number of days or weeks that it takes to heal after a hamstring strain. The best assessment is continuous evaluation at regular intervals from a skilled clinician who has experience rehabilitating hamstring injuries (hi!).
I will collaborate with you to develop and execute a plan to get better and help you navigate the busy intersection as safely as possible. If you have a hamstring injury, reach out and let’s get started on a resilient rehab program.
Katie Noble is a Doctor of Physical Therapy, a journalist, and a runner. She enjoys empowering and supporting female runners with evidenced-based education.
- Green B, Bourne MN, van Dyk N, et al. Br J Sports Med 2020;54:1081–1088
- Hamstring muscle strain in runners. Askling, Carl, Thorstensson, Alf. NSA> 23:3, 67-70, 2008.
- Malliaropoulos N, Isinkaye T, Tsitas K, et al. Reinjury after acute posterior thigh muscle injuries in elite track and field athletes. Am J Sports Med 2011;39:304–10.
- cite: Reurink G, Goudswaard GJ, Tol JL, et al. Br J Sports Med 2014;48:1370–1376.
- Hickey J, Timmins R, Maniar N et al. Pain-Free Versus Pain-Threshold Rehabilitation Following Acute Hamstring Strain Injury: A Randomized Controlled Trial. Journal of Orthopaedic & Sports Physical Therapy. 2020;50(2):91-103. doi:10.2519/jospt.2020.8895
- van Dyk N, Behan FP, Whiteley R. Br J Sports Med 2019;53:1362–1370
- Ribeiro-Alvares J, Marques V, Vaz M, Baroni B. Four Weeks of Nordic Hamstring Exercise Reduce Muscle Injury Risk Factors in Young Adults. J Strength Cond Res. 2018;32(5):1254-1262. doi:10.1519/jsc.0000000000001975
- Ardern CL, Glasgow P, Schneiders A, et al. Br J Sports Med, 2016;50:853–864.
Dr. Katie Noble, PT, DPT, SCS 