Why hamstring eccentrics are hamstring essentials

Why hamstring eccentrics are hamstring essentialsThorborg, in British Journal of Sports Medicine, 2012


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Discussion:

In a nutshell, this study took advantage of some prior studies that have been mentioning how effective eccentric work may be for preventing hamstring injuries. Hamstring pulls are a nightmare for any sport coach, and especially track coaches. I am always looking for ways to keep my athlete’s hamstrings healthy. Two things I have picked up in the last year have been mandatory soft tissue work prior to practice via softballs/lacrosse balls, and then a higher priority on glute strengthening. After seeing the results of this study, you can bet that next year, eccentrically based hamstring work in full ranges of motion will also be in there. Here are some details of the study and why I will be including this in my athlete's training.

When athletes pull a hamstring, it takes a long time, on average, to get that hamstring back to full strength. Research is cited in this study that showed that levels are only around 90% at 6 weeks post-injury and it took 16 weeks to return to full strength. Because of the length of this time frame, Thorborg proposed that the focus of rehab needs to be on replicating the function of the hamstrings, rather than the amount of time it takes to restore full strength.


In regards to hamstring function, there have been some excellent recent findings. One idea has been that eccentric based hamstring work will cause the highest amount of torques the hamstring can produce to be at it's longer ranges of motion, rather than shorter ranges. Many hamstring pulls and tears occur directly before ground contact in the sprinting motion, when the hamstring is in an elongated state. Because of this, it makes sense that working hamstrings hard eccentrically through a full range of motion can help build strength and maximal torque in the range where the pulls may occur.

For Thorborg’s study, data was collected from 942 soccer players. It was found that putting players on a 10-week rehabilitation program of Nordic Hamstring Curls caused a reduction in hamstring re-injuries by 70%! (The Nordic Hamstring Curl is a eccentric natural glute-ham raise, [You must be registered and logged in to see this link.]


Based on this study, I would strongly recommend the inclusion of some full-length eccentric based work for hamstrings into your own training program, whether that be through the Nordic Curl, Glute-Ham, Romanian Deadlift, or standard leg curl. Another nice trick to maximize the eccentric output of each exercise can be to use two legs for the concentric portion, and then only one leg for the way down. For example, if you were using a lying hamstring curl on a machine, you would lift the weight concentrically (up) with two legs, and then take a leg away to lower the weight with only the other leg. Hopefully, we will see a vast reduction in hamstring pulls in athletes in the near future with this method.

All of my athletes old and mature enough to do weights sessions complete eccentric hamstring curls, as described. Relatively light weight, up with both legs, down very slowly with one leg. No more than 6 reps per leg (ideally 5 or fewer), 3-5 minutes recovery between sets. The older athletes will start on Romanian Deadlifts in a winter or two when they've demonstrated a more mature level of core strength.

I prefer the eccentric curls over Nordics as you can always adjust the weight of the load so that the entire range of motion can be worked during an eccentric curl. The nature of a basic bench hamstring curl machine (non-pulley) is that the proportion of the load decreases towards the end of the range of motion, corresponding to the point where the hamstring is at its longest and therefore weakest.

In comparison, Nordics tend to focus more on loading only through shortened to mid-range hamstrings, and sprinters with relative or absolute hamstring weakness will get less out of a Nordic given that the bulk of eccentric hamstring load during sprinting is at 85% or greater length. Frequently, at this length, while completing a Nordic, even the strongest of participants have long since dropped to the floor.

Great article, I do this with my kids after first learning the skill from Ashley Rowan and Shane Naylor in 1994, then I didn't use them for many years until I joined Vasily Grischenkov back in 2003 when I was recovering from my last hamstring injury. I continued to use this drill for many many years and never suffered another hammy injury. This was certainly one of the main contributing factors to 7 years without injury. I did a calf in the last few months before I retired in 2010.

Having said that, it's not always easy to find a partner to hold your heels, or even harder, a GHG machine to do them in. But a regular part of our strength and conditioning/core program.