Remember in the 1980s there was an advertisement that ran in many of the US pulp martial arts magazines by Thomas Kurz. The ad showed him performing the splits between two chairs with a blond babe in a swimsuit sitting on his leg. How many of us looked at that and thought, gee I wish I was as flexible as him? But it wasn’t just Mr. Kurz advertisement pushing for greater flexibility. There were the “Chuck Norris” jeans with the extra leg gusset, the leg stretcher which looked like some medieval torture device, and a host of other equipment, videos, books and the like. Even at the dojo there was an emphasis placed on stretching to increase flexibility, but the reasons why were never very clear. Some would say that it was to kick higher, others would say so that you could kick faster, while others said it was to reduce injury.
We did so many kinds of stretches in class: partner, dynamic, and static, but in the end I never did get very flexible. All said, I don’t think my Karatedo is any the worse for wear because I didn’t gain this ultra flexibility. This brings me to the topic of today’s blog post flexibility in Karatedo – what is it and do you really need it.
I think part of the problem early on in my Karatedo training was that stretching and flexibility were not explained properly let alone defined, nor was the rationale of why you needed it. Let’s start then with defining flexibility properly. In physical activity flexibility is usually defined in terms of range of motion (ROM) of a specific joint, i.e. a joint moving from full flexion to full extension. For example, you can flex your arm at the bicep and then relax and extend the arm outwards are far as possible. Next, let’s look at the rationale behind flexibility. In day-to-day life it’s obvious that we need an adequate range of motion to function normally otherwise our quality of life would be very poor indeed. Imagine trying to take a step and not being able to extend your legs sufficiently – you’d become tired very quickly, maybe slip, and possibly fall. But this definition and rationale are more for everyday life.
What about Karatedo? For Karatedo, we need to divide things a little further in terms of definitions and include static and dynamic ROM. Static ROM involves flexion and extension of a joint while stationary, and the opposite is true for dynamic ROM. Which one is important for Karateka? Or are both equally important? Are the two related? For example, maybe I can do a static straddle split to a 140 degrees, but what if I cannot achieve that same angle, for example, while performing a strong and quick side-kick? Is there any value to doing the static stretching? It can be a bit of a conundrum.
I’ve always been a firm believer that “less is more” so along those same lines more flexibility (especially the hyper-flexibility espoused in popular martial arts advertisements) is not necessarily better. Let’s look at a few reasons why that may be the case. First, in traditional Okinawa Karatedo Kata, kicks are almost always delivered below the waist (the only exception that I can think of in Nahate is the crescent kick in Pechurin and Suparempei). These kicks in traditional Okinawa Karatedo only require a normal range of motion, i.e. a level of flexibility that is used in daily life. It is only in the sporting context of Karate that we begin to see kicks above the waist.
Second, although it is commonly held that flexibility can reduce or prevent injury there is limited scientific research that supports this. For example, a review by Thacker, et. al. (2004) found that,
Stretching was not significantly associated with a reduction in total injuries
Similarly, Ingram (2003) concluded that,
…the evidence suggests that increasing range of motion beyond function through stretching is not beneficial and can actually cause injury and decrease performance
Hyper-flexibility, especially hyper-flexibility of the hip and abductor muscles, may actually increase chances of injury. For example, in a study of female dancers age 8 to 16 years of age, dancers with hyper hip abduction were more prone to foot or ankle pain and injury around the tendins (Steinberg, et al, 2012). Granted young female dancers are not your average middle-age Karateka, but it still is food for thought.
Finally, prolonged stretching is well-known to cause a serious reduction in the amount of force that a muscle can potentially generate, particularly for stretches held longer than 60 seconds (see Kay & Blazevich, 2012). I think most of us agree that maximal force production is one of the most important aspects of effective Karatedo technique and practices that deter this need to be re-examined.
What all this points to is that you don’t need hyper-flexibility to perform Karatedo Kata or technique at a skillful level. Only a normal range of motion that you would use in your daily life is required. Any stretches or flexibility training should be geared towards this taking into account your age and level of health, as well as the advice of your physician. If you to train beyond the normal range of motion, know what the pros and cons are, and make sure you check with your physician before you start.
Update – this video by Professor Doug Richards from the Physical Education & Health department at University of Toronto explains fundamental concepts and misconceptions about stretching.