Note: This article in rebuttal to "Kicking for the Moon" elsewhere on this site.
Many times in the Chinese Martial Arts, arguments ensue over the supposed usefulness of particular techniques in terms of martial ability. Too often, people tend to throw away techniques or manners of performance without thinking through the exact reason or benefits that said technique can provide. This can happen with old techniques that are said to be for looks only, but more commonly, it is said of the modern wushu approach to training these forms and actions. Wushu has gain a reputation as being “dancing” (used in the pejorative most times) and no good for combat. What people often misunderstand is that while training technique is important in the Martial arts, training general athleticism, power, and flexibility are also important (some may say more important) as they lay the foundation for which the techniques will gain their power and effectiveness. With all the debate back and forth about so many issues, the best approach is to base our decisions on the evidence available to us. A good example is the outside crescent kick that Ted comments on.
The high swinging “lotus kick” or “outside crescent” as performed in solo practice trains not specific mechanical performance or functional movement per se, but rather trains neuromuscular patterning, synergistic recruitment of the lumbo-pelvic hip complex (LPHC) and open chain power production of the lower extremities. It is an important training kick for several reasons. First, because it is an open chain movement, meaning it does not gain it’s force from a direct opposition to the ground i.e. pushing against it with the supporting leg as in a side or thrust kick. This requires the body to support the kick with the spine and power it with the hip. Also it is a very difficult kick in that most of the power from it is in the frontal (abduction and adduction) and transverse (side to side- where most injuries occur). Plane It also takes the hip joint through a dynamic Range of Motion (ROM) thus resetting and adapting the myotactic (stretch) reflex resulting in increased hip ROM. To assume that the kick as is in a combat situation is naïve and the product of watching too many movies. That actual method of using the kick is actions like leg reaping throws, sweeping knockdowns, and high “descending” roundhouse kicks striking with the posterior lateral surface of the heel.
So then, a question comes up; why should the kick be divided in to “martial” or “dance”. With the above point clearly established, the form of the solo kick should provide a few things only: proper alignment and function with in extreme ROM, Core activation and stabilization of the lumbar spine, and improved joint kinematics in the LPHC. The points that are called the “martial” kick actually do the opposite.
The position of the knee is an important issue but the idea that the leg needs to be bent for proper shock absorption is, I believe, unsupported. While sagittal plane loading (up and down) of the knee contraindicates the locking of the joint to provide proper deceleration from a jump or explosive flexion/extension, the force that would be incurred with the contact of a kick to an object or opponent is lateral.With the leg in full extension, toe pointed, and foot everted (hooked and tilted in) creates what is called a “three point extension”. This is the preferred potion for lateral loading of the knee. If a three-point extension is held the entire leg posterior, anterior as well as lateral, and medial supports are recruited. There result is added strength to the joint and stability of the capsule protecting the ligaments from tearing. Obviously, if the force exceeds a certain limit the joint will dislocate, but the possibility of a person producing enough force with one leg alone in an open chain movement is remote-not impossible, but remote.
On the other hand, if the knee is in flexion (bent) you will have inhibition of the anterior aspect of the leg reducing activation of the vastus lateralis (one of the quads) the gluteus medius and tensor fascia latae (TFL) to abduct and brace the knee against impact. Also, you would be producing a torque on the joint as the leg struggled to stabilize the tibia which would almost certainly rotate in, thus starting the injury mechanism for ACL or MCL injury (Barrata et. al., 1988)
The physics of it also are flawed. If the leg is straight and the appropriate musculature is well developed, the force will be evenly distributed over the whole force arm (or force leg, pun intended) while if the leg is bent you have added an axis of rotation at the knee. An easy experiment can demonstrate this. Take a straight stick and a bent one. Mimicking the forces of the kick, place a weight on one end of each and see which one can more easily be held level.
Next, the position that is described as being the correct “martial” way to perform the kick: “When a proper crescent kick is thrown the back should be hunched slightly and definitely not straight. This is a dance kick, back straight and even arched—not a martial kick which requires the back muscles and psoas to be engaged throughout the kick.”
First, there is no physical way to throw any kick, in dance or martial art, without the activation of the psoas. In fact, it is impossible to stand erect and walk with out it being active. The psoas is one of the primary hip flexors and therefore is recruited in any leg lifting action (Juker et al. 1998).
Second, the position in the example does exactly the opposite of what is intended. When the back is in spinal flexion, the extensors (iliocostalis, logissimus, spinalis, multifidus, and the psoas) are inhibited (McGill et al. 2001). The psoas is both an extensor of the lumbar spine and a hip flexor (Juker et al. 1998) . Proper recruitment and mechanics of the LPHC is dependent on the even activation of the psoas and the back extensors to stabilize and provide a base from which to produce power (McGill, 2001). Letting the back hunch and the pelvis to tit backward decreases activation of these important muscles in the back, greatly increasing the risk of serious injury even during no contact performance and decreasing power and force production in the kick (Gertzbein, 1988, McGill, 1998). The advice to hunch the back when performing the kick is at best bad form and contraindicated and at worst, in my opinion, dangerous in the extreme. From personal experience, I can attest to the injurious quality of this movement distortion in kicking.
The inability to lift the leg without spinal flexion is a serious movement pathology and has been shown to be the cause of a great deal of low back injuries and chronic LPHC problems. (Krajcarski et al., 1999)
The hunching of the back also extends the back muscles forcing them into eccentric contraction (or a contraction while lengthening). If a person then decides to put force into the kick, these tissues are at extreme risk for rupture and soft tissue damage (Solomonow, 2003). Done habitually, over use injuries at almost assured, although they may not manifest at the site of compensation. Neck problems, hip problems, and arthritis of the spine, shoulder, and hip would be presumed to be the inevitable outcome for the majority of people. Also, these symptoms may not manifest until late in life when the body’s natural muscular supports begin to atrophy.
Lastly, I am confused about the point made about the retraction of the leg after the kick. While retraction of the kick is important for balance training, As long as the hip is properly trained in ROM and dynamic strength, full range of motion should never cause pain or discomfort. If you are unable to go past a certain point of hip ROM without pain, that is indicative of a movement distortion in the kinetic chain and should be addressed. It does not need to be the result of anything in the area of pain but, from what I know about the back and what the science tells us, the hunched back posture would be a first suspect. The issue is, of course, impossible to solve with out individual examination and function movement screenings to discern the trouble.
What it really boils down to is this: The hunched back, bent leg, and incomplete arc of a lotus kick is indicative of pathological movement distortions. If you are unable to keep your back in neutral or near neutral positioning, keep your knee straight, or complete a full arc in that position, your body is compensating for lack of flexibility, core strength, and/or proper neuromuscular patterning of biomechanically correct movement. This will undoubtedly lead to ineffective leg and hip movement (kicking, sweeping, or otherwise) at best and overuse or traumatic injury at worse. The “dance” kick is for all intents and purposes the biomechanically correct form.
Citations:
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