I am a huge fan of stretching. Nothing relaxes me more than a good bout of static stretching and nothing prepares me better for teaching a martial arts class than dynamic stretching. Almost all physical activity requires some sort of flexibility. Simply bending over to pick up a pencil requires flexibility in the shoulders, erector spinae, lumbar, hips, and hamstrings. In one study, runners who exhibited greater hamstring flexibility had fewer injuries than their less flexible counter parts (Hreljac et al. 2000). Golfers who have the flexibility to separate their upper and lower torso have greater back swing and therefore more ball velocity than those who can not (Sell et al. 2007). Flexibility in martial arts is critical for most of the techniques. High kicking requires flexibility in your legs, hips, and lumbar, while punching requires flexibility in your shoulders, traps, and lats.
In human tissue, there are two types of stretch that can take place. Elastic stretch is when the tissue returns to its previous state, and plastic stretch is when the tissue does not return to its previous state (Hall, 2007). Muscle tissue has only elastic properties, while ligaments and tendons have both elastic and plastic properties (Hall, 2007, Hedrick, 2000). If the objective of flexibility is to retain a greater range of motion, then plastic deformation should be the goal (Hedrick 2000). However, elastic stretch will allow for a good snap at the end of a technique, and taking advantage of the stretch shortening cycle will allow for faster, multiple techniques such as a double jab or kick.
One exercise that I incorporate into my training program is speed kicks. A speed kick is more of a rhythm drill than a speed drill (although speed and rhythm are very closely related). Think of the Rockettes doing the can-can. This one exercise allows us to dynamically stretch through a full range of motion while using the elastic property of muscle to strike a pad with snap and quickly recoil. We also take advantage of the stretch-shortening cycle of muscle by repeating the movement using plantar flexion to push off of the ground. Indecently, this movement also an example of Newton’s third law , the law of reaction, which states for every action there is an equal and opposite reaction; foot pushes into the ground, the ground generates an equal and opposite reaction, and also a good example of strain energy. As the arch of the foot becomes deformed, the different tissues of the foot store mechanical energy. The energy is released during the push off generating greater acceleration and consequently more force (Hall, 2007).
Through his drill, my students achieve greater flexibility and learn how to control energy achieved through various means.
Hall, S. (2007) Basic biomechanics. McGraw Hill, NY, NY.
Hedrick, A. (2000) Dynamic flexibility training. National Strength & Conditioning Association Volume 22, Number 5, pages 33–38
Hreljac, A., Marshall, R., Hume, P. (2000) Evaluation of lower extremity overuse injury potential in runners. Medicine & Science in Sports and Exercise. 0195-9131/00/3209-1635/0
Sell, T., Tsai, Y., Smoliga, J., Myers., J., Lephart, S. (2007) Strength, flexibility, and balance characteristics of highly proficient golfers. Journal of Strength and Conditioning Research, 2007, 21(4), 1166–1171
Tuesday, October 26, 2010
Sunday, October 10, 2010
Jeet Kune Do: The Fighting Stance
In his quest for excellence in fighting, world famous martial artist and actor, Bruce Lee, broke with tradition, questioned convention, and re-thought the fighting game. The flash and speed that was portrayed on film was theatre arts, the real genius was in the science behind the art. In his book, Jeet Kune Do: Bruce Lee’s Commentaries on the Martial Way, Little (1997) describes a bed ridden Bruce Lee, due to a back injury, who filled seven volumes of notes on the art and science of combat. At the base of this scientific method of combat was the stance.
Traditionally, martial arts stances were either low with a wide base for stability or high with a narrow base for agility. The martial art style of Jeet Kune Do uses a hybrid of the two. The practitioner faces forward. The feet are a little further than shoulder width apart and one step in length apart. The heel of the back foot is slightly raised, the knees are slightly bent, and the body is slightly crouched (Tom, 2005). Through observation and experience, Bruce Lee developed a stance that reached in to the sciences of physiology, biomechanics, and kinesiology.
All fighters must have stability (the resistance to the disruption of equilibrium) and balance (the ability to control equilibrium) (Hall, 2007) to withstand any outside forces brought on by an opponent. The position of the feet is the first critical point as the feet are the base of support. The base of support for the Jeet Kune Do stance is angular as opposed to a square stance. The angular stance increases the outermost regions of the area in contact with the ground (Hall, 2007) and allows the practitioner to better withstand both mediolateral and anteroposterior forces; forces that can cause torque that result in angular displacement and disrupt stability.
Another benefit to using an angular stance is the greater ability to keep the center of gravity with in the larger base of support. The center of gravity is the point where the body’s weight and mass are equally distributed (Hall, 2007). If the weight of the fighter, or the line of action, moves beyond the boundaries set by the base of support, the center of gravity becomes disturbed and the fighter will be unable to maintain balance. By keeping the knees slightly bent and maintaining a slightly crouched, yet upright position, the fighter is able to keep the center of gravity lower to the ground, providing greater stability (Hall, 2007), and use the greater base area to shift weight from one foot to the other as the need arises.
The Jeet Kune Do stance allows for stability but it is also allows for movement and agility. Because the knees are slightly bent, there is a degree of leg extension that can occur allowing the practitioner to use the large leg muscles for explosive movements. This force production is an example of Newton’s third law, the law of reaction, which states for every action there is an equal and opposite reaction; as the muscles push into the ground, the ground generates a reaction force and pushes the body in the opposite direction (Smith, Weiss, & Lehmkul, 1996). The bent knees also permit a slight bouncing movement. Physiologically, the eccentric and concentric contractions of the movement will activate the stretch-shortening cycle of muscular contraction and allow for more ballistic movement (Bartlett, 1999).
The most important aspect of the Jeet Kune Do stance is the position of the rear foot. As Bruce Lee stated, “Unlike the traditional flat footed practice, the left heel (assuming a right lead) is raised and cocked, ever ready to pull the trigger and go into action. The left heel is the spark plug, or better still, the piston of the whole fighting machine” (as cited in Tom, 2005, p. 27). His observations were correct. Biomechanically, as the arch of the foot becomes deformed, the muscles that produce ankle and foot movement (primarily the soleus and gastrocnemius) along with the ligaments, tendons, and the plantar fascia, store mechanical energy also known as strain energy (Hall, 2007). The energy is released during the push off phase of movement generating greater acceleration and consequently more force (Hall, 2007).
As with all physical tasks, there is a degree of education and training that accompanies the Jeet Kune Do fighting stance. Any muscular imbalances that would prevent the practitioner from properly executing the stance need to be addressed. The timing and coordination of any movement needs to be reviewed. Lastly, proper cross training to improve the function of the techniques needs to be conveyed.
Areas of concern for muscular imbalance are the alignment of the knees, elevation of the rear foot, and evenly distributed weight. An assessment using the National Academy of Sports Medicine Corrective Exercise protocols will reveal any imbalance (Clark, Corn, & Lucett, 2007). For example, if the knees adduct the medial gastrocnemius and the medius and maximus gluteus will need to be strengthened while the lateral gastrocnemius, the tensor fasciae latae (TFL), and the adductors will need to be inhibited and lengthened. If the knees abduct, the adductor complex and the gluteus maximus need to be strengthened and the piriformis and the gluteus medius and minimus need to be inhibited and lengthened. If the feet flatten, the medial gastrocnemius and the tibialis muscles need to be strengthened; additionally the peroneal complex and the lateral gastrocnemius need to be inhibited and lengthened. Asymmetrical weight shifting indicates that the gluteus medius on the side of the shift and the adductor complex on the side opposite the shift need to be strengthened and the TFL and the piriformis on the side of shift need to be inhibited and lengthened (Clark, et al., 2007).
Although the movements associated with the Jeet Kune Do fighting stance are minimal, as with any movement, there is an associated degree of coordination. Sequential muscle action moves from proximal to distal and is generally initiated by the larger muscles (Bartlett, 1999). In the case of the Jeet Kune Do fighting stance, the legs, by way of ground force reaction, initiate the majority of the movement. Due to the generated force of the leg muscles, the momentum needs to be controlled. Momentum is the quantity of motion that an object possesses (Hall, 2006). Excessive acceleration and the lack of control will telegraph any follow up movement as well as disrupt stability so that the practitioner is unable to maintain a stable base to properly execute any follow up techniques.
Once the muscular imbalances are corrected and coordination is achieved, physical training to improve the movements can begin. Obviously there are a number of training protocols that can be used to gain strength, endurance, and flexibility. Assuming the practitioner has achieved adequate balance, stability, muscular endurance, and strength; plyometric exercises will enhance the movements discussed. Plyometrics are used to improve the stretch-shortening cycle to facilitate recruitment of motor units (Wilmore, Costill, and Kenney, 2008). The elastic energy stored in the muscles (in this case, the muscles of the upper and lower legs) during the eccentric contraction is used for ballistic movement during the concentric contraction. Examples of appropriate plyometric type exercises include jump squats, single leg jump squats, and jumping rope.
The stance used in any martial art is just the beginning. However, developing a sound foundation starts with a stable base and the knowledge and skill of how to manipulate that base. Knowing the fundamental scientific principles will allow the practitioner to build, from the ground up, solid support, solid movement, and consequently a solid fighting game.
References
Bartlett, R. (1999). Sports biomechanics: reducing injury and improving performance. (pp. 154- 155) New York: Routledge.
Clark, M, Corn, R., & Lucett, S. (2007). Corrective exercise specialist: home study course. Movement Assessment. Calabasas: National Academy of Sports Medicine.
Hall, S. (2007). Basic biomechanics. (pp. 62,257, 399-448) New York: McGraw-Hill.
Little, J., & Lee, B. (1997). Jeet Kune Do: Bruce Lee’s commentaries on the martial way. (p. 16) Boston: Tuttle Publishing.
Smith, L., Weiss, E., & Lehmkul, L. (1996). Brunstrom’s clinical kinesiology. (p. 25) Philadelphia: F.A.Davis.
Tom, T. (2005). The straight lead, the core of Bruce Lee’s Jun Fan Jeet Kune Do. (pp. 25-33) Boston: Tuttle Publishing.
Wilmore, J., Costill, D., Kenney, W. (2008). Physiology of sport and exercise. (p. 195) Champaign: Human Kinetics.
Traditionally, martial arts stances were either low with a wide base for stability or high with a narrow base for agility. The martial art style of Jeet Kune Do uses a hybrid of the two. The practitioner faces forward. The feet are a little further than shoulder width apart and one step in length apart. The heel of the back foot is slightly raised, the knees are slightly bent, and the body is slightly crouched (Tom, 2005). Through observation and experience, Bruce Lee developed a stance that reached in to the sciences of physiology, biomechanics, and kinesiology.
All fighters must have stability (the resistance to the disruption of equilibrium) and balance (the ability to control equilibrium) (Hall, 2007) to withstand any outside forces brought on by an opponent. The position of the feet is the first critical point as the feet are the base of support. The base of support for the Jeet Kune Do stance is angular as opposed to a square stance. The angular stance increases the outermost regions of the area in contact with the ground (Hall, 2007) and allows the practitioner to better withstand both mediolateral and anteroposterior forces; forces that can cause torque that result in angular displacement and disrupt stability.
Another benefit to using an angular stance is the greater ability to keep the center of gravity with in the larger base of support. The center of gravity is the point where the body’s weight and mass are equally distributed (Hall, 2007). If the weight of the fighter, or the line of action, moves beyond the boundaries set by the base of support, the center of gravity becomes disturbed and the fighter will be unable to maintain balance. By keeping the knees slightly bent and maintaining a slightly crouched, yet upright position, the fighter is able to keep the center of gravity lower to the ground, providing greater stability (Hall, 2007), and use the greater base area to shift weight from one foot to the other as the need arises.
The Jeet Kune Do stance allows for stability but it is also allows for movement and agility. Because the knees are slightly bent, there is a degree of leg extension that can occur allowing the practitioner to use the large leg muscles for explosive movements. This force production is an example of Newton’s third law, the law of reaction, which states for every action there is an equal and opposite reaction; as the muscles push into the ground, the ground generates a reaction force and pushes the body in the opposite direction (Smith, Weiss, & Lehmkul, 1996). The bent knees also permit a slight bouncing movement. Physiologically, the eccentric and concentric contractions of the movement will activate the stretch-shortening cycle of muscular contraction and allow for more ballistic movement (Bartlett, 1999).
The most important aspect of the Jeet Kune Do stance is the position of the rear foot. As Bruce Lee stated, “Unlike the traditional flat footed practice, the left heel (assuming a right lead) is raised and cocked, ever ready to pull the trigger and go into action. The left heel is the spark plug, or better still, the piston of the whole fighting machine” (as cited in Tom, 2005, p. 27). His observations were correct. Biomechanically, as the arch of the foot becomes deformed, the muscles that produce ankle and foot movement (primarily the soleus and gastrocnemius) along with the ligaments, tendons, and the plantar fascia, store mechanical energy also known as strain energy (Hall, 2007). The energy is released during the push off phase of movement generating greater acceleration and consequently more force (Hall, 2007).
As with all physical tasks, there is a degree of education and training that accompanies the Jeet Kune Do fighting stance. Any muscular imbalances that would prevent the practitioner from properly executing the stance need to be addressed. The timing and coordination of any movement needs to be reviewed. Lastly, proper cross training to improve the function of the techniques needs to be conveyed.
Areas of concern for muscular imbalance are the alignment of the knees, elevation of the rear foot, and evenly distributed weight. An assessment using the National Academy of Sports Medicine Corrective Exercise protocols will reveal any imbalance (Clark, Corn, & Lucett, 2007). For example, if the knees adduct the medial gastrocnemius and the medius and maximus gluteus will need to be strengthened while the lateral gastrocnemius, the tensor fasciae latae (TFL), and the adductors will need to be inhibited and lengthened. If the knees abduct, the adductor complex and the gluteus maximus need to be strengthened and the piriformis and the gluteus medius and minimus need to be inhibited and lengthened. If the feet flatten, the medial gastrocnemius and the tibialis muscles need to be strengthened; additionally the peroneal complex and the lateral gastrocnemius need to be inhibited and lengthened. Asymmetrical weight shifting indicates that the gluteus medius on the side of the shift and the adductor complex on the side opposite the shift need to be strengthened and the TFL and the piriformis on the side of shift need to be inhibited and lengthened (Clark, et al., 2007).
Although the movements associated with the Jeet Kune Do fighting stance are minimal, as with any movement, there is an associated degree of coordination. Sequential muscle action moves from proximal to distal and is generally initiated by the larger muscles (Bartlett, 1999). In the case of the Jeet Kune Do fighting stance, the legs, by way of ground force reaction, initiate the majority of the movement. Due to the generated force of the leg muscles, the momentum needs to be controlled. Momentum is the quantity of motion that an object possesses (Hall, 2006). Excessive acceleration and the lack of control will telegraph any follow up movement as well as disrupt stability so that the practitioner is unable to maintain a stable base to properly execute any follow up techniques.
Once the muscular imbalances are corrected and coordination is achieved, physical training to improve the movements can begin. Obviously there are a number of training protocols that can be used to gain strength, endurance, and flexibility. Assuming the practitioner has achieved adequate balance, stability, muscular endurance, and strength; plyometric exercises will enhance the movements discussed. Plyometrics are used to improve the stretch-shortening cycle to facilitate recruitment of motor units (Wilmore, Costill, and Kenney, 2008). The elastic energy stored in the muscles (in this case, the muscles of the upper and lower legs) during the eccentric contraction is used for ballistic movement during the concentric contraction. Examples of appropriate plyometric type exercises include jump squats, single leg jump squats, and jumping rope.
The stance used in any martial art is just the beginning. However, developing a sound foundation starts with a stable base and the knowledge and skill of how to manipulate that base. Knowing the fundamental scientific principles will allow the practitioner to build, from the ground up, solid support, solid movement, and consequently a solid fighting game.
References
Bartlett, R. (1999). Sports biomechanics: reducing injury and improving performance. (pp. 154- 155) New York: Routledge.
Clark, M, Corn, R., & Lucett, S. (2007). Corrective exercise specialist: home study course. Movement Assessment. Calabasas: National Academy of Sports Medicine.
Hall, S. (2007). Basic biomechanics. (pp. 62,257, 399-448) New York: McGraw-Hill.
Little, J., & Lee, B. (1997). Jeet Kune Do: Bruce Lee’s commentaries on the martial way. (p. 16) Boston: Tuttle Publishing.
Smith, L., Weiss, E., & Lehmkul, L. (1996). Brunstrom’s clinical kinesiology. (p. 25) Philadelphia: F.A.Davis.
Tom, T. (2005). The straight lead, the core of Bruce Lee’s Jun Fan Jeet Kune Do. (pp. 25-33) Boston: Tuttle Publishing.
Wilmore, J., Costill, D., Kenney, W. (2008). Physiology of sport and exercise. (p. 195) Champaign: Human Kinetics.
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