The hurdlers stretch is ubiquitous in karate. It is also potentially damaging to the knee of the bent leg and not particularly effective as a stretch for the hamstrings of the extended leg. Hurdlers use the stretch because it approximates the position they are in the air when clearing the hurdles. Most coaches recognize the danger of this stretch and take measures to reduce the negative effects while still employing it for hurdlers. The reason is pretty simple, hurdlers need to hurdle, and they will hurdle until they are no longer competing in the sport. Their determination to win, and their relatively short competitive careers tip the cost/rewards scale in favor (slightly, and debatably) of the use of this stretch. In this article I will argue that hurdlers stretches are inappropriate for karate people because the stretch is intrinsically dangerous to the knee, that there are important differences between karate and hurdling that need to be kept in mind when evaluating the relationship between risks and rewards associated with the use of the hurdlers stretch, and finally I will suggest some alternatives to the hurdlers stretch.
Before I get into the body of this article I want to direct our readers attention to several online articles that present similar concerns regarding hurdlers stretches.
The hurdler stretch is unique because it can be used for either stretching the hamstrings or quadriceps, dependent upon whether body lean is forward or backward (See Fig. 5). When used for stretching the hamstrings, the individual leans forward. In this position a considerable stress is placed on the medial structures of the bent leg; strain or discomfort in the hip and groin area may also occur because the femur of the bent leg is placed in extreme rotation. A safer alternative is to bend the knee in front of the body rather than to the side. This is the stretch originally recommended by Cailliet12 and subsequently adapted for use in a testing protocol by The Cooper Institute for Aerobics Research37.
From the Fairfax County Public Schools Website comes this excellent summary of risky exercises (note the inclusion of neck roles and straight leg sit ups as well as the hurdlers stretch in the list of dangerous practices):
Research has shown that many exercises are contraindicated and may do more harm than good. All of the exercises listed below cause degenerative effects over time. Depending on the student’s physical condition, some students may be injured immediately. The most vulnerable areas, are the neck, the knees, and the back. Here is a list of specific exercises that can be dangerous and should be avoided
“the traditional hurdler’s stretch”
This exercise has you sit on the ground with one leg straight in front of you, and with the other leg fully flexed (bent) behind you, as you lean back and stretch the quadricep of the flexed leg. The two legged version of this stretch is even worse for you, and involves fully bending both legs behind you on either side. The reason this stretch is harmful is that it stretches the medial ligaments of the knee (remember, stretching ligaments and tendons is bad) and crushes the meniscus. It can also result in slipping of the knee cap from being twisted and compressed.
From the Allexperts website comes this response to a question regarding stretching in hapkido by veteran group fitness leader and personal trainer Linda Banning.
…The next 2 are the grand-daddies of bad: The hurdler stretch puts a lot of torque on the backward bent knee and it’s simply not necessary. This is a commonly accepted substitution: Sitting on the floor, extend the left leg in front of you. Bend the right leg and place that foot against the left inner thigh. Lower the right knee toward the floor as far as possible to open up the hips. Hinge forward at the hip, lowering the torso forward toward the extended left leg. Change legs and repeat. Laying back with bent knees twisted around you is awful whether you do one at a time or both. This is a high risk stretch with practically no benefit. It is designed to stretch the quadriceps group, but there are a lot of good exercises that do this better and much more safely. The knees are very unstable joints. They are simply two large bones held together by a network of ligaments and then tendons that attach muscles to bones around the joint. Ligament and tendon tissue lack elastic properties. When we do stretches, our goal is to elongate and increase flexibility in the MUSCLES that are attached around the joints being stretched. Localizing a stretch to just the knee is attempting to stretch the tendons and ligaments that will not stretch unless torn or damaged….
For reference here is a picture showing the medial collateral ligaments.
Thinking About Risks vs Benefits
Exercise physiologists, athletic trainers, and other sports science people generally assume that the parameters of the specific sport that their client is engaged in are already set and the options then are to condition the athlete to be able to perform according the the demands imposed by that sport, or to consider retiring from it. Karate is however quite varied, and even within the confines of ‘traditional’ methods can be personalized to a great degree.
Hurdling places very specific sorts of demands on the bodies of hurdlers. Hurdlers need to be quick, flexible, agile, and have good cardio endurance. They do not need to worry about the integrity of their knees when they are being swept, receiving thigh kicks (ashi kitea), kicking pads or heavy bags, lifting and twisting motions, or even rapid changes in direction. The benefits of dangerous, but highly sport specific exercises like hurdlers stretches may be appropriate for some hurdlers, but they (emphatically) are not worth the risk for karate people who require much greater joint strength and stability in order to perform.
Most of us have either trained with someone, or can imagine someone, who for no lack of effort, does not have the most impressive roundhouse kick in the world (due to flexibility issues), but who is still vigorously participating in karate Now imagine a different person who has painful, unstable knees, who because of his knees is unable to rapidly move laterally in kumite, is unable to kick at all without pain, is unable to dart in and out, unable to lift, throw or sweep. Which person has the greater handicap? I know this is an extreme example ( I have trained with people in both categories), but I use it to illustrate the point that even if it were the case that in order to perform roundhouse kick well one needed to do hurdlers stretches, the potential cost to the rest of one’s karate may be too high. Hyper-focusing on one skill can cause one to lose sight “of the forest for the trees”.
Of course it is neither true that hurdlers stretches are necessary in order to be able to execute a roundhouse kick, or that the damage that hurdlers stretches can cause to one’s knees would not also impact kicking ability over time. There is no way to eliminate all of the danger associated with training to prepare for intrinsically dangerous activities like fighting, however one thing that distinguishes karate groups from “fight clubs” is that we try to develop and refine our abilities over the course of a lifetime in ways that we could not do if we just “threw down” all the time. By reducing the unnecessary, dangerous, and unproductive elements of our training we are more likely to have the injury free time we need to be able to refine our abilities.
While we all know people who seem to be able to do amazing amounts of potentially damaging conditioning without apparent harm, this is usually due to their genetics. Hard physical activities (like karate) tend to be self selecting so that for every apparent superman there are probably scores of people who dropped out due to injuries resulting from poor programing or dated ideas regarding physical fitness. Every scientist knows to be careful about extrapolating from anecdotes (i.e. “my sensei did reverse butterflies his entire life and could still kick lick a mule”), karate people would do well to keep this in mind when evaluating claims regarding the safety of particular regimes of exercise.
The good news is that the classical hurdler stretch is not necessary to prepare one to perform roundhouse kicks. There are safer and more effective alternatives.
Alternatives to the Standard Hurdler Stretch.
The main requirements for a good round kick are, abduction of the kicking leg, abduction and/or hip extension in the support leg, knee flexion and extension with speed, balance, and targeting.
Abduction of the kicking leg requires both that the adductors are flexible and that the abductors are strong enough to lift and support the leg throughout the kick.
Here are some exercises that help with both adductor flexibility and abductor strength:
Self Myofascial release for the Adductor Complex:
Adductor Static Stretch:
The Side Lunge:
The abductors can be further warmed up prior to kicking using the following exercises:
The Forward Hurdler Walk
The Backward Hurdler Walk
Dynamic Hip Mobility Exercises:
If tight hamstrings are inhibiting your ability to extend your knee during kicking try these instead of the traditional hurdlers stretch:
Self Myo Fascial Release for Hamstrings:
The Inverted (or modified) Hurdlers Stretch:
Standing Hamstring Stretch:
Here are exercises that promote hip extensibility (remember that hip extension requires flexible hip flexors):
Hip Flexor Stretch:
Stability Ball Hip Extensions:
Strengthening the supporting leg by incorporating squats and lunges into your fitness routine, and using a wobble board to enhance your balance will help give you a stable base from which to kick. This naturally results in greater confidence, extension, and control when kicking.
Dynamic Lower Body Warm Up (including hamstrings):
Here is a good general lower body warm up very similar to what I employ with my own students. I recommend omitting the stationary hip twists and Frankenstein walk for students with knee or back issues. This warm up also helps with lower body balance and agility, and is especially good for warming up the ankles. Proper ankle stability and alignment is essential for the supporting leg when kicking.
I recommend that most people reduce the amount of rapid kicking they do in the air (without hitting a target), and instead practice hitting light targets with precision (not emphasizing power) until they have very good control of their kicks. Students with poor control of their kicks are more likely to injure themselves when they attempt to kick powerfully or in the context of partner work. Once the kicks can be executed lightly and fluidly with precision, then it may be time to begin kicking heavier targets with greater force.