During hamstring injury rehab, does it matter if you start lengthening (eccentric) exercises earlier or later in the program?
Research reviewed: Early versus delayed lengthening exercises for acute hamstring injury in male athletes: a randomised controlled clinical trial
Hamstring injuries are one of the most prevalent injury types across sport with one of the highest re-injury rates as well (some papers show high as 30% re-injury rate in the first two weeks following return to sport!).
One of the most effective, research proven ways to facilitate hamstring injury rehabilitation is via “lengthening” exercises where the muscle is contracting while lengthening, aka eccentric load through the hamstring.
Building up the hamstring’s capacity to tolerate high eccentric load (in other words, strengthening the hamstring via eccentric/lengthening training) is really important because eccentric stress creates the highest demand on the muscle group, particularly during sprinting (I won’t get into specifics but you can search for “hamstring terminal extension eccentric stress” if you’re interested in more details).
Therein - one of the key questions for medical providers and injury rehab specialists has been: when is the best time to introduce eccentric training into hamstring rehab to optimize recovery?
The paper I’m reviewing this week sought to shed more light on that topic.
Methods
The researchers took 90 participants between the ages of 18-36 (median was 26) with an MRI-confirmed acute hamstring injury (meaning it happened recently) and then randomly assigned them into two groups:
The first group, early lengthening, completed eccentric exercises on day 1 of rehabilitation.
The second group, delayed lengthening, completed eccentric exercises only after they were able to run at 70% of maximal speed.
Outside of that difference, the rest of the rehabilitation program was the same.
The two key outcomes were return to sport time (time from injury to full, unrestricted games) and reinjury rate within 12 months after returning to sport (measured at within 2 months, between 2-6 months and beteween 6-12 months)
Results
The return to sport in the early lengthening group was 23 days (95% of subjects ranging between 16-35 days) and 33 days (95% of subjects ranging between 23 and 40 days) in the delayed lengthening group. When adjusted, the data showed no statistical significance.
The reinjury rates following return to sport between groups showed no difference at any of the time markers (within 2 months, between 2-6 months, and between 6-12 months)
Practical takeaways
A few things to talk about here.
Firstly, the reinjury rates were relatively cut and dry in terms of both groups not showing much difference.
For return to sport, the two groups showed no statistical difference but the early lengthening group did generally come back earlier (23 days vs 33 days). 10 days, on the grand scale of things, is trivial but when if you’re on a timeline or in high level sport, 10 days can be a huge deal.
That being said, definitely need many more studies for anything even in the range of definitive but this might be hinting at something.
From my perspective, if there’s no increased risk for introducing eccentrics early (as long as you’re starting and progressing them properly), then it makes sense to lean that direction - especially if time is a major concern.
Thank you for reading and thank you for your time. If you need our help with injury recovery, fitness, and/or mindset coaching (we offer virtual & in-person avenues, including online programs) head over to the website.
Dr. Rajpal Brar, DPT has a doctorate in physical therapy from Northern Arizona University, and runs his own in-person and online sports medicine and performance business, 3CB Performance, in West LA and Valencia, CA and partners with Quantum Performance in which he further combines his movement expertise and fitness training background to rehab & train elite athletes. He also works at a hospital — giving him experience with patients in the immediate healthcare setting and neurological patients (post stroke, post brain injury) — and has been practicing for over 6+ years. Brar is additionally training at UCLA’s mindful awareness research center (MARC), has a background in multiple sports both playing and coaching and discusses sports injuries, fitness and performance his own YouTube Channel. You can follow him on Twitter at @3cbPerformance.