Imagine a world with no hamstring strains…
It would be pretty nice, wouldn’t it? We may not be quite there yet as an athletic community, but the information you’ll find from three great experts on the subject will help to get us all just a little farther down to the road to a world of faster athletes with fewer debilitating injuries.
It’s been almost three years since I did a “roundtable” style article, having elite and respected coaches weigh in on a topic of importance and debate. I’m beyond excited to break that long silence with a cast of incredible coaches with nearly a century of combined experience in the field of athletic performance. The four coaches we have for today’s roundtable are:
- Irving “Boo” Schexnayder (Legendary track and field/performance coach, consultant and educator.)
- Bret Contreras (The most well-read and educated hip-extension professional in the world. Glute training revolutionary.)
- Chris Korfist (Wildly successful Illinois sprint coach whose athletes haven’t lost time to hamstring injuries in the past 3 years.)
- Henk Kraaijenhof (One of the world’s greatest sprint coaches will be featured in Part II of this article)
You can check out more about these coaches in their formal bio’s at the end of this article. Henk’s take on the topic will actually be found in the next section of this roundtable coach-cast, as he has written a short, formal article on the topic.
Let’s get to the questions and answers, and start solving the hamstring injury puzzle.
What are the biggest muscular/fascial and functional risk factors for athletes in terms of a hamstring pull? Are there any skeletal or structural factors that might put an athlete at risk in your experience?
Boo Schexnayder
The two factors I see most commonly that trigger hamstring issues are decreased mobility in the foot and ankle, and anterior pelvic tilt. When the bones of the feet and ankle fail to glide properly against each other and ankle dorsiflexion is limited, the tibia-fibula complex becomes fixed at its lower end, and in compensation becomes hypermobile at its upper end producing the hamstring problem. If the pelvis is tilted forward during gait, a hamstring problem will undoubtedly result at some point.
On some occasions, this results indirectly from a poor training mix, but more often it is skill related, resulting from poor acceleration mechanics. A lot of coaches punt here, thinking that the athlete is anatomically predisposed to the problem, but in my experience, that is never the case.
Bret Contreras
The biggest risk factor is a prior hamstring strain. It yields a biomechanically inferior muscle, and the scar tissue impacts the way the hamstring functions for the rest of the athlete’s career. But there are most definitely other anatomical and architectural factors at play. Just like we can utilize engineering to examine the loads placed on vehicles or machines, we can utilize musculoskeletal modeling to examine the loads placed on the human body during exercise.
Some individuals’ skeletal structures are surely more prone to experiencing greater hamstring strains in terms of tendon attachment points and moment arm lengths at both the knees and hips and also the precise lengths and arrangements of the muscle tissue play a role as well. Since exercise can alter properties such as pennation angle and fascicle length, this indicates that we can influence the likelihood of hamstring strain injury through optimal training protocols.
Chris Korfist
The biggest factor is that the hamstring is doing the job of the glute, hip extension. If the glute is not firing well, the hamstring will be asked to extend the hip as well as flex the knee which is asking a lot of the muscle. If we follow the muscle train up the pathway to the opposite armpit, and fascia or a muscle is “off”, it could cause the hamstring get pulled a little bit further and you get your strain. In Be-Activated, we try to put the body into sync so the glute is the dominant hip extensor. If the glute is driving, the hamstring can then function the way it should, as a secondary hip extensor and a primary knee flexor.
Do you feel that the risk of hamstring pulls can be generalized? How much variability and individual factoring would you account for in hamstring injuries?
Boo Schexnayder
There is a lot of individual factoring that should go on, but not anatomical factoring. The level of an athlete’s training is one factor. Athletes who train at high levels are much more likely to develop muscular imbalances and fascial restrictions that result in hamstring pulls, which is why diversity of training becomes so important at high levels. Undertrained athletes are much more likely to show postural problems in gait that produce injuries.
Another factor is the volume of training, I think it’s easy to see how overuse can contribute to these problems. An athlete’s sport or event is a key individual factor. For example, posterior displacement of the head of the femur can result in hamstring issues, and that’s a very likely occurrence with a long jumper who experiences impact at takeoff. With a sprinter, this wouldn’t usually be a contributing factor.
Finally, the athlete’s quality of movement comes into play. Athletes who show poor levels of intermuscular coordination, or who tend to guard near the ends of their ranges of movement are much more likely to develop hamstring issues. These are common with undertrained or poorly trained athletes.
Bret Contreras
No. It is very important for the reader to start consuming hamstring research if he or she wants to properly understand hamstring strain injury risk factors. For example, Spanish researcher Jurdan Mendiguchia and New Zealand researcher Matt Brughelli have churned out a couple of excellent papers on this topic:
Hamstring Strain Injuries: Are We Headed in the Right Direction
A Return to Sport Algorithm for Acute Hamstring Injuries
It is not one factor alone that predicts hamstring strain injuries. Humans tend to be reductionists and seek to narrow everything down to one reason, but it is in fact the interrelationship between various things such as anatomy, architecture, motor programming, fatigue, pelvic stability, hamstring flexibility, eccentric and concentric knee flexion strength and power, eccentric and concentric hip extension strength and power, left to right side imbalances, gluteus maximus and adductor strength synergy, contralateral hip flexor flexibility, and of course prior hamstring strain. As you can see, an athlete could possess very strong hamstrings but could still wind up with an injury due to things like excessive fatigue, weak glutes, or inflexible hamstrings.
Chris Korfist
I think I have gotten to the point where I see some physical characteristics that may lead to a hamstring issue. The bouncy walker’s sometimes get a strain. They lack the ankle rocker (dorsiflexion range) to get their weight forward. When they sprint, the chain is stretched and on the curve, that right leg has to stretch really far before the contraction and it pops. Or, the duck footed athlete sometimes gets one on a curve as well. The stretch is too far and the hamstring has to do the work of the glute. I think that is why it is important to do glute work with feet in different positions. The glute needs to drive, no matter where the foot is. But, generally speaking, if the hamstring is asked to do too much, it will go.
What is your experience with environmental factors in hamstring injury rates?
Boo Schexnayder
Surfaces are a big factor. Large work volumes on harder surfaces tend to reduce mobility in the foot and ankle and trigger hamstring problems. We forget the foot’s role as a shock absorber, and when pliability in the foot is lost chances of hamstring injuries increase dramatically. I think the role of cold weather in hamstring injuries is greatly overstated.
Bret Contreras
I do not have experience in this area, as I am a strength coach, not a sport coach or track & field coach.
Historically, the most common hamstring injury “prevention” method for the uninformed is static stretching. Is there a role of static stretching in order to prevent hamstring issues?
Boo Schexnayder
I think static stretching does have a role and some value in training when used properly, but as a hamstring injury preventative it’s pretty much useless. In fact, in coaching culture we have overvalued static stretching so much that the opposite situation is more common- athletes overstretching (and prematurely fatiguing) the hamstring and placing it at additional risk as a result. Overstretching fatigues certain proprioceptors and gives a false feeling of looseness, we have to be smart enough to understand the issue at a more sophisticated level.
Bret Contreras
There is no black and white; things are usually different shades of gray. Though static stretching has been overvalued by the majority of coaches over the past couple of decades, there’s no reason to denounce it. Static stretching does not acutely change any mechanical properties in the musculotendinous complex; it works on the nervous system by modulating sensation. Therefore, it can and should be used in certain situations. For example, static stretching the hip flexors is often recommended prior to certain activities, and it might even be wise to static stretch the hamstrings prior to an exercise such as deadlifts if it helps the athlete use better form. I’d trade a slight decrease in strength for a marked improvement in lumbopelvic control any day of the week for athletes who struggle to get into proper deadlift position on account of inflexible hamstrings.
Chris Korfist
This again gets into the Be-Activated realm, and only people who have tried this will understand what I am talking about but muscle length has a relationship with neural state. The more relaxed someone is, the more muscle length. That is why we tie diaphragmatic belly breaths into our routine. I can stretch someone’s hamstring and get it to 90. But if they are in a sympathetic nervous state, the length will go right back to where the brain feels it is safe. If we reset the nervous system to be parasympathetic, however, the brain will give the muscle the length. So, it is not uncommon to increase someone’s flexibility by 20-30% by changing the breathing pattern. When the psoas and glute are working properly, the brain will give even more length to the muscle. So, we don’t stretch, we activate and get the length we need form the source, the brain.
What is your take on the role of therapy/soft tissue work in the prevention of hamstring injuries, and optimization of hamstring performance?
Boo Schexnayder
I think a common thread through all of my answers has been the role of maintaining skeletal alignment and mobility as being the key to hamstring injury prevention. Manual therapy and soft tissue work are among the best possible ways to enhance mobility and alignment. There is a reason why elite athletes in individual sports often leave the coach behind but bring the therapist with them to the competition.
Bret Contreras
I think it is another tool that can and should be used. Similar to static stretching, its role has been overvalued by many coaches over the past couple of decades, but again there’s no reason to avoid using it depending on the circumstance. However, I’m not a manual therapist, so my knowledge in this area isn’t anecdotal but instead reliant upon witnessing the effects of self-myofascial release (SMR) and reading the research.
Chris Korfist
Our therapy is Be-Activated and it gets the right muscles to do the right work. If we get our breathing down and go through our psoas and glute activation, the hamstring will fall into place. I think this is why people who use Be-Activated don’t have many hamstring issues. I have not had an issue in the last three years on my track teams.
What are some strength exercises that you have found useful in the prevention of hamstring injury? Any types of sprint related work that improves mechanics specific to solving gait issues related to hamstring pulls? Are there ways that you would individualize strength work based on athletes to reduce the incidence of a hamstring issue?
Bret Contreras
Nordic ham curls, Romanian deadlifts, good mornings, back extensions, and leg curls. In particular, loading up the stretch position and focusing on the eccentric phase seems valuable, which is why Nordic ham curls and RDLs are so popular.
I believe that sprinting mechanics is very important in preventing hamstring strains, but I do not have a lot of experience in this area since I’m not a track & field coach. Therefore, I can’t comment on what drills and cues are most effective for this purpose.
I would simply ensure that athletes possess sufficient hamstring, glute, and core strength by prescribing proper amounts of hip extension, knee flexion, and core stability exercises.
Boo Schexnayder
No special strength exercises, in fact, I steer away from them. A key to the prevention of hamstring issues is to train the leg to operate and fire as nature intended, which means that we should train in a functional manner with an eye on movement rather than individual muscles. We shouldn’t be concerned only about absolute levels of leg strength, but that the individual muscles in that kinetic chain are being strengthened in the correct proportions. Isolating the hamstring to strengthen it just leads to greater risk of developing imbalances. Besides, no track athlete has a weak hamstring ever… it’s like looking for a pianist with weak fingers. The hamstring tests weak because it is placed in a compromised position by skeletal and fascial misalignments.
As far as sprint work, nothing is needed other than a sound, gimmick-free approach to teaching acceleration and maximal velocity mechanics. Many fads in the sprint coaching world are directly contributing to the rash of hamstring injuries, because of their effects on pelvic alignment and strike angles. Finally, as far as strength training, keep it functional, gimmick-free, and emphasize large ranges of motion whenever you can to assure proper core-peripheral strength ratios.
Chris Korfist
I think if we isolate the hamstring to do the work and we are not in sync from a recruitment standpoint, we can get in trouble. But once we are recruiting properly, I like closed chain stuff. A basic for me is RDL’s on my kBox. It loads the eccentric aspect unlike any piece of equipment I have tried. I also like standing leg curls on the kBox as well. The glute has to stabilize the standing leg while the opposite hamstring curls. In this exercise, I like to emphasize the heel coming as high as possible. That is a characteristic of elite sprinters that I have my athletes emulate, the high carriage of the lower limb. It seems like it folds perfectly up into the thigh. From an energy expenditure standpoint, the lever is shortened and would require less energy to swing and more momentum to bring the knee higher. I do this off the kBox as well. We step off the kBox and pull the heel up and through.
I know the Weyand research shows very little time difference in the time of the swing leg, but I think that every little bit helps. And of course, there are many other factors that contribute to the knee lift but I try to work on as many as possible. I also like prime time runs or stiff-legged runs. They tend to hit the hamstrings pretty good as well, and it focuses on the relaxation on the glide phase. I am looking to find a way to use the Nordic hamstring exercise more efficiently, as It is hard to quantify.
To individualize, that is a difficult topic because different exercises work for different people. Off the top of my head, for the athletes that run on the lateral portion of their foot, I will add adductor magnus exercises, which are hip extensions with feet turned in. These help athletes to achieve a better plant on the ground. Remember that the adductor magnus is a hip extensor too. Some athletes that been brought to me with hamstring injuries have actually been adductor magnus issues.
Track and field is an easy sport to quantify the training load, while team sports can be more difficult. What are your thoughts on guidelines for the frequency of various types of sprint, acceleration, and deceleration work, within track and field, and/or team sport play?
Boo Schexnayder
I can give you pages of volumetric guidelines for different forms of sprint work, but the volumes that can be attained while still displaying quality vary greatly from individual to individual. I just always coach high-end speed development work with an eye for quality and no preconceived notions of what the volumes will be. Team sports are a challenge because if the volumetric guideline is surpassed, but the play still isn’t being run correctly, what do you do?
I really feel that the key to keeping team sport athletes healthy and surviving the volumes you need to meet team tactical goals is employing diversity in the training program. Quite often the role of the strength and conditioning coach is misunderstood. In team sports where you must perform so many repetitions of certain sport skills, it is the job of the strength and conditioning coach to provide contrast to those movements, not to just pile on more volume of the same stuff and beat up tissues the same way over and over again.
Bret Contreras
I’m not a sport coach or track & field coach so I can’t comment with confidence here, though I think this question is a very important consideration.
Chris Korfist
Regardless of the sport, I always use drop off. Once an athlete is not running as fast, I cut them loose. Track is different than team sports though because sprinting is our sport. With football, I think many teams get slow as the season progresses. Flys with a drop off would be a great way to monitor that and keep top-end speed. Just look at what happened at the veteran combine. No one ran well because they don’t sprint anymore.
At what point should coaches be concerned about training volumes in team sport play? What is the most practical way for team sport coaches to keep track of volumes and tolerance to prevent injury, if this is necessary?
Boo Schexnayder
That’s an interesting question. One of the key factors that tend to proliferate hamstring risk factors are repetitive movements, like the right-left pattern we see in gait. Team sports are acyclic and often have the advantage of more diverse patterns of movement, yet repetitive movements are still part of the conditioning training culture in those sports. I strongly recommend evaluating each position in a team sport, identifying what (if any) movements are habitual and frequently repeated, and charting numbers of repetitions. Of course in some sports this just isn’t practical, but strives to quantify each type of work in minutes. For example, in basketball, the starting, stopping, and direction changes of half-court play are tougher on the body in some ways and pose different demands than the fast break stuff, so quantify practice time spent on each in minutes. Often you’ll find you can actually train more in aggregate by limiting minutes spent on some higher-risk forms of team training.
Bret Contreras
I’m not a sport coach or track & field coach so I can’t comment with confidence here, though I think this question is a very important consideration.
Chris Korfist
Omegawave and HRV are things that come to mind but I don’t have the luxury of getting all of my athletes to comply. So, I ask them how they feel. If they feel tired, I cut them back. If they start improving once they are warmed up, I will let them continue. I think too many coaches have this sense that all athletes want to get out of workouts. Maybe they do because they are exhausted. But for the most part, they want to train. If you make it fun and put guidelines to the workout, people usually do what they are ready to do. Some of my best athletes have trained one day a week and competed once a week.
Is there a basic checklist, or system that you could use or suggest to coaches to assess athletes for risk of hamstring injury?
Boo Schexnayder
Of course some hamstring problems aren’t really hamstring issues, adductor problems and several others can masquerade as hamstring problems, so an accurate assessment is a key first step. I have already listed the key risk factors. The first thing I try to ascertain is whether the problem that produced the hamstring injury is training produced or impact related. For example, excessive squatting that tightens the erector spinae and alters pelvic alignment would be training related. These training related factors are common in highly trained athletes and often come in bunches. Undertraining can be the culprit as well, usually when athletes lack postural strength or skill.
When training issues aren’t the case, collisions are the culprit, and in gait, the collisions always occur between the feet and the ground. That means you use a ground-up evaluative philosophy, checking mobility and alignment in the feet first and working on up through the ankle, tib-fib complex, etc. until you find the cause. In most cases regular monitoring of foot mobility and periodic adjustment can head off many potential hamstring issues.
Bret Contreras
I think that in order to truly gauge hamstring strain injury risk, a coach would need hundreds of thousands if not millions of dollars of equipment, ranging from MRI, to ultrasound, to isokinetic dynamometer, to electromyography, to force plate, to motion capture, to radar, along with fancy software systems to assist in analyzing the data. The Nordboard is a cool new invention designed to test eccentric knee flexion strength and determine if asymmetries exist. But along with strength measurements, you also need to know a lot of other things such as those I described above. See the Mendiguchia & Brugelli papers for more info along those lines.
Chris Korfist
Go through a Be-Activated sequence.
Continue to the next portion of this coaching roundtable, with thoughts on the same topic from coaching legend, Henk Kraaijenhof. (Part II)
Expert Bios:
Bret Contreras has a master’s degree from ASU and a CSCS certification from the NSCA. He is currently studying to receive his PhD in Sports Science at the Sports Performance Research Institute New Zealand (SPRINZ) at AUT University in Auckland, New Zealand. Visit his blog at BretContreras.com and his research review service at www.StrengthandConditioningResearch.com.
Boo Schexnayder is regarded internationally as a leading authority in training design, possessing 34 years of experience in the coaching and consulting fields. Most noted for his 12 years on the Track and Field coaching staff at LSU, he is regarded as one of the world’s premier coaches, having developed 19 NCAA Champions and 10 Olympians. Schexnayder has coached multiple World Championship and Olympic medalists and has been on several national team staffs, including the staff of Team USA at the 2008 Beijing Olympics. He also possesses 13 years of experience in NFL player development and combine preparations. He frequently lectures and consults domestically and internationally in the areas of speed and power development, training design, motor learning, and rehabilitation. He currently operates Schexnayder Athletic Consulting and serves as director of the USTFCCCA’s Track and Field Academy and Thibodaux Regional Medical Center’s performance division. Prior to his collegiate and international career, Schexnayder was a successful prep coach for 11 years, coaching football, track, and cross country.
Chris Korfist has been coaching track for 22 years in Illinois. He has coached at Hinsdale Central, Downers Grove North and York HS, producing 59 All-state track athletes, 3 individual state champions, 2 team state champions, 3 second-place team finishes, and 2 3rd place finishes. He owns the Slow Guy Speed School which is a gym that focuses on running and athletic development from which other All-state athletes have trained. He used to run the Inno-sport website and wannagetfast.com with Dan Fichter. He also had the opportunity to work occasionally with some Olympic sprinters and other professional athletes.
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