One thing fun about my job is that I never know what’s going to come through my door that I’m going to have to figure out how to treat. Recently I had an former professional soccer player who was super fit but had strained his hamstrings several times and wanted to get back to playing in his league games. Muscle strains are something I generally consider easy to treat. You just rest them for some time, then start working on increasing muscle circulation, strength, and in my opinion the last would be range of motion. But the problem was when my player started asking questions like: How long will I be out? How do I know when I am ready to return to play? How strong should my hamstrings be? How come my hamstring strength is equal to the other side, my range of motion is equal to the other side, I feel completely normal, but when I play a game I start to feel the pain return just a little? Should I stop play as soon as I feel that pain? What’s the best warmup? What’s a good warmup when I don’t have much time? Should I stretch before I play? Those were a lot of good questions and some of which I had less than definitive answers. So when asked questions I do what I normally do, which is go to pubmed.com, start typing in keywords, reading reviews, commentary and randomized controlled trials. Often musculoskeletal injuries are obscure enough that there is little data, but I was amazed at how much there was on hamstring injuries, particularly with football (soccer for us Americans) which is their number one injury with recurrent strains being a considerable problem, costing team outcomes, affecting player’s careers, and costing millions of dollars at the pro level. So where the money is, so the research goes. There was a lot to learn here that I figured I could apply to muscle strain injuries with my other patients. Also in collecting and reading the papers that I have I had a fair amount of comments and ideas for where there are still holes in the research that need answering to optimise recovery and ideally prevent injuries from happening in the first place.
So now I have stack of papers 2-3 inches thick. I have read a number of them that I think would make for good blogs, so where to start? I guess here:
We determined the frequency of strength disorders in 26 athletes with a history of hamstring muscle injury and recurrent strains and discomfort. We also assessed the effectiveness of rehabilitation to correct muscle performance. After concentric and eccentric isokinetic assessment, 18 athletes were found to have strength deficits, as determined by statistically selected cutoffs of peak torque, bilateral differences, and the flexors/quadriceps ratio. The discriminating character of the eccentric trial was demonstrated, combining a preferential eccentric peak torque deficit and a significant reduction of the mixed eccentric flexors/concentric quadriceps ratio. The athletes with muscle imbalances followed a rehabilitation program individually adapted from their strength profile. Treatment length was from 10 to 30 sessions and resulted in isokinetic parameter normalization in 17 of 18 subjects. Isokinetically corrected subjects were observed for 12 months after return to athletics. None sustained a clinically diagnosed hamstring muscle reinjury. Subjective intensity of pain and discomfort were significantly reduced, and they all returned to their prior level of competition. These results demonstrate that persistent muscle strength abnormalities may give rise to recurrent hamstring injuries and discomfort. An individualized rehabilitation program emphasizing eccentric training based on specific deficits contributes to a decrease in symptoms on return to sports.
This wasn’t the first paper I read but I thought it was well written, it was cited by a lot of reviews and I was familiar with the authors as they had done isokinetic research on the treatment of tendinitis which I had blogged on before.
So, what they found was that in 26 male athletes with a history of hamstring injury and recurrent strains (18 soccer players, 7 track and field & 5 martial artists) 18 of them had strength deficits that when given a custom exercise program directed at correcting those deficits. Those deficits were some combination of either right vs left leg strength, hamstring strength vs quadriceps strength, or eccentric strength vs concentric strength, with the most striking finding being mixture of low slower eccentric hamstring strength as compared with faster concentric quadriceps strength. The imbalances were corrected with custom isokinetic exercises that normalized the imbalances in the 18 athletes with the deficits and they were followed for a year, none of whom had any additional hamstring injury. So it interesting that they spent their efforts on strengthening, as opposed to stretch and/or trendy passive modalities and none of the athletes were re-injured.
The downside of this study is that the testing and exercise programs were done on isokinetic exercise equipment, which is expensive (I think in the range of $30,000) and generally used today only for research such that very few teams, physical therapists, gym goers, and even universities have it available. So it worked in concept but it’s not very practical for even testing let alone training.
Though this is an older 2002 study that’s perhaps not ultimately practical, it is still very relevant. What I would like to see done now (to the point I started pricing used isokinetic testing equipment, tempered only by the fact isokinetic equipment was all the rage in the 80s, in spite of the price I never saw it do anything but gather dust in physical therapy clinics in the 90s, and disappeared in the 2000s) is see performance on knee and hip. Specifically with isokinetic equipment correlated with strength on more common and likely more effective exercises such as leg extensions and leg curls (for purer isolation of quads, hamstrings and right vs left legs). Also more efficient and functional exercises such as squats, lunges, pulls and RDLs, or the new hotshot exercise for hamstring strains and soccer players which is the Nordic Hamstring Curl.
Thanks for reading my blog. If you have any questions or comments (even hostile ones) please don’t hesitate to ask/share. If you’re reading one of my older blogs, perhaps unrelated to neck or back pain, and it helps you, please remember Spinal Flow Yoga for you or someone you know in the future.
Chad Reilly is a Physical Therapist, obtaining his Master’s in Physical Therapy from Northern Arizona University. He graduated Summa Cum Laude with a B.S. Exercise Science also from NAU. He is a Certified Strength and Conditioning Specialist, and holds a USA Weightlifting Club Coach Certification as well as a NASM Personal Training Certificate. Chad completed his Yoga Teacher Training at Sampoorna Yoga in Goa, India.