From Overwhelmed to Informed: Hamstring Injury Insights

212 hamstring injury studies distilled into 3 systematic reviews and meta analyses, served here in just 481 words (with a bit of complimentary waffle in there too!). 🚀

For busy sport practitioners, it’s hard to stay up to date with the latest research whilst doing everything that’s required day-to-day.

Not just the sheer volume of new studies, but also one study alone is not much use, you need to keep your finger on the pulse of how a subject area is evolving. Last week I mentioned the virtues of systematic reviews and meta analyses. This is where these wonderful things really come in handy, and I thought I’d illustrate this with hamstring injuries.

Unfortunately hamstring injuries are one of the highest frequency injuries across a number of sports. Fortunately that does mean they’ve garnered a bit of attention over the years from sports science research. As such there have been a few recent systematic reviews on hamstring mechanisms, risk factors and prevention.

Let’s start with mechanisms. Danielsson et al (2020) reviewed 26 of 2,372 screened studies and found a stretch-type injury to the hamstrings is caused by extensive hip flexion with an extended knee. Sprinting is a high risk activity for hamstring injuries, particularly during the late swing phase of the running gait cycle due to excessive muscle strain from eccentric contraction.

As we’ve often found with injuries, not all risk is equal.

A systematic review and meta analysis by Green et al (2020) that included 78 studies with over 8,000 hamstring strain injuries in 71,324 athletes found the two strongest risk factors were: Older age and previous hamstring strain injuries. This highlights the importance in better understanding and preventing index hamstring injuries, such is the increased risk of subsequent injuries once an athlete/player has sustained that first injury.

But what do we know to be effective when it comes to hamstring injury prevention and risk management? Evidence in this space has been mixed, also limited by limitations of the methodologies used. But Rudisill et al (2023) did review 108 articles and concluded eccentric strengthening reduces injury incidence and improves hamstring strength, fascicle length, H/Q ratio and limb asymmetry. It’s important to increase flexibility, with static stretching providing greater but more transient gains compared to other stretching methods. These findings show promise but better quality studies (in relation to Cochrane Library protocol) are needed, albeit challenging in this context.

That’s the power of systematic reviews and meta analyses though. 212 research articles included across 3 reviews that enable consistent trends to be identified, results somewhat validated and more confidence in the outcomes. As a treat too, the first two studies mentioned above are open access so if you’re keen to dig deeper, or fancy a bit of bedtime reading, please do go and check them out.

Stay informed, and stay effective