On yesterday’s blogpost, I provided a link to the best hamstring article I’ve ever read in any journal. The journal article was written by Jurdan Mendigutxia and Matt Brughelli. I was so impressed with the study that I tracked down Jurdan and asked him to conduct an interview. I had to translate a little bit for Jurdan as his English isn’t his strongpoint. Here’s the interview:
1. Hey Jurdan, please introduce yourself to the readers. Where were you born, where do you live, what are your educational and professional backgrounds, and what is your current occupation?
Hello readers! My name is Jurdan Mendigutxia. I’m a 32 year-old Sport Physical Therapist born in Pamplona (Spain), which is next door to where Ernest Hemingway wrote his famous book “Fiesta”. He spent good time here and all the readers are invited to visit us and run ahead the bulls around the streets to improve the quality of their S&C program! I was a soccer player and played a few times for the U18 and U19 Spanish National Team. After University I worked for the Research and Studies in Sports Medicine Center in my city where we give assistance to top level athletes for 6 years. In between I took time to visit in my opinion some of the best scientifically places in the world. PT is my passion and I want to see in action the best. I spent months in the Oslo Sport Trauma Research Center in Oslo, the only place in the world created for prevention issues in sport. Two years later I was with the ACL King, Tim Hewett and his “family “( Kevin Ford, Greg Myer, Jensen Brent) in Cincinnati, who have more than 200 papers published, just learning how a scientific guy has to work and learning all about ACL injury prediction, prevention and rehab. This could be the place that has made me most impact on me because of the scientific nature of their methods.
Just because it was so close I took the opportunity to visit “Spine King” Stuart McGill spent some time with him in Waterloo. Stu always has great ideas. Finally, I had very good luck in my life to meet Matt Brughelli. We have many professional things in common (our passion for the hamstrings!) and a very good relationship. We’ve done some research together and are always discussing new ideas. There are never bad times to discuss our views and many nights have been spent in front of the PC trying to explain mine new ideas or understand his new ideas. My main interest area is prevention of sports injuries . Actually, after being a consultant in terms of prevention and rehab to different professional soccer teams and head of rehab and prevention for Athletic Club Bilbao professional soccer team, I built my own facility called Zentrum. I rehab professional athletes and see difficult cases and still act as a consultant for different professional teams.
I’ll let you in on a secret Bret but don’t get jealous: Some people joking call me “The Ham Guy!” Haha! (Editor’s note: Now we just need an “Adductor Magnus Guy” and we’ll have the primary hip extensors covered!)
2. Jurdan, you know an awful lot about the hamstrings. Tell us some things we don’t know about the hamstring musculature.
I will tell you the latest findings that for me are interesting:
1. Recent research (in press) shows that during sprinting where injury mostly occurs, hams is a more powerful hip extensor (greater than knee flexor) during swing phase than in the stance phase, where the GM is more powerful. This agrees with its moment arms and confirms older biomechanics studies ( Novacheck TF 1998). This means that we might need more than one approach to attack the prevention and/or rehab and confirm that as Novacheck TF shows moments arm at the hip for the hams are double than at the knee. In other words, the hamstrings are twice as powerful as hip extensors than knee flexors during swing phase.
2. The semitendinosus muscle is the unique hamstring muscle that has architectural partitions (Kubota et al 2007). It has an intersectional tendon that divides the ST in proximal and distal portions and it’s been shown that exercise can activate more one or the other. The clinical meaning for me and an idea that I am focused on is that because proximal and distal hams injuries exist maybe we need to categorize and target our exercises for prevention and rehab as proximals and distals. We need to know not only which muscle we want to target but also the location within the muscle! Looking at this, ask yourself if it is enough to do a single exercise to prevent hams injuries? I think not.
3. More related to muscle physiology, the importance of the elastic series component giant protein TITIN during lengthening (binding with actin) contractions and its different adaptations to resistance training has been highlighted. This could be the future to understanding muscle mechanics and injury prevention. To introduce you in this concept here is some basic stuff about it (see Lindstedt S et al. 2001 – that is free).( http://www.ncbi.nlm.nih.gov/pubmed/11719600)
3. How can we reduce the incidents of hamstring injuries in sports?
Good question! Even though many people think that they have the recipe, looking at the evidence is not easy. In the last decade we’ve seen an explosion of eccentric exercise. This was used for prevent muscle injuries and tendinopathies, but recently a systematic review by prestigious Cochrane database conducted by Goldman and Jones shows that there is no evidence to support that the notion that hams injuries are prevented through eccentric training and that popular hamstring strengthening protocols have contradictory findings with one small study showing benefits and decreasing injuries and 2 bigger studies showing the opposite. This interesting finding was compromised by poor methodology and the use of only one exercise, the Nordic Hamstring exercise, that works the knee flexors eccentrically but with a fixed hip. But, didn’t we say above that the hip extension moment arm was double than the moment arm at the knee? This could be a reason but undoubtedly better studies are needed.
Moreover, if you analyze in soccer the number of hams injuries 28 years ago, you’ll see that they are equal to current data in epidemiological studies. A very nice study conducted by Ekstrand J et al. 2010 analyzing hams injuries in the most prestigious Europe soccer teams (27) and with a follow up of 8 years doesn’t find any hams injury reduction. Well guys, don’t you think that is time for reflection? The hams injuries remains equal!! Looking to scientific evidence literature I find 2 major flaws: first is that almost no single study meets the criteria needed in a prospective study designed to find injury related risk factors. More than 200 subjects and 20 -50 injuries are needed to achieve statistical power. Second and more important is that currently research studies isolate risk factors. In my opinion isolating static variables can’t give you the real picture. You can’t reduce the part and retain the meaning of the whole!! Force, mobility and stability are all interconnected around the body! I think that this could be one of the reasons why hams injuries don’t decrease. We need to assess each individual and address the weaknesses. I promise you that in my career I tested isokinetically hundreds of pro players at the lab and there is no correlation with injuries. This is the reason why I hate general recipes. Each individual is an individual case and remember that hams injuries are multifactorial!
4. Tell us how the gluteus maximus and hamstring musculature can work together to increase pelvic stiffness and how this effects force and mobility.
Just looking for the literature you can observe that both gluteus and hams are connected to the pelvis via sacroutuberous ligaments and both have been shown to participate in SIJ force closure (preventing forward rotation of the sacrum) and therefore affect its stiffness and stability (see Pool Gouzdwaard et al. 1998, Vleeming 1989). So in addition to participating in hip extension and knee flexion the glutes and hams have to stabilize the SIJ. How much force is used for each action and how weakness of hams or gluteus can affect each other is unknown as of yet but it could be a nice research area. For example Cibulka MT et al. 1986 has shown an increase in hams force after SIJ mobilization in people with anterior pelvic tilt and speculated that this could increase hams length and compromise strength.
5. Last question, do you feel that the field of Physical Therapy could stand to be more evidence-based?
Of course! I would like to tell you one thing. When in University I started working in the research center and I was very surprised and frustrated during the first few weeks. There, the strength coaches control and measure many variables like power, RFD…etc, physiologist control the progression of the athletes objectively, the nurses measure everything…and I ask myself: “What are we the Physical Therapists supposed to measure and control objectively?” This is one of my headaches! I need to do things that are evidence based in the literature and know the “why” and need to measure my own processes. How can a professional athlete return to sport without measuring anything? We can’t learn anything if he get injured again. Of course we can observe that sometimes a measure is not valid but at least we know now that this measure could not be valid. If we record and measure systematically we can obtain feedback from our process and improve our system. For example, you can see my last article at Physical Therapist in sport that a hams algorithm rehab is scientifically fundamental. It was only one year ago that I made these changes but this makes my system much better!!