Tens(ion) + (Int)egrity
The optimal ramp angle, as determined by the dynamic ramp device, is based on a stance predicated on the principles of Biotensegrity.
Fascial continuity suggests that the myofascia acts like an adjustable tensegrity around the skeleton – a continuous inward pulling tensional network like the elastics, with the bones acting like the struts in the tensegrity model, pushing out against the restricting ‘rubber bands: Tom Myers, Anatomy Trains (1.)
A ski stance based on the principles of bio-tensegrity must be learned and rehearsed in a step-by-step process. It is neither natural or intuitive although elite skiers and racers such as Shiffrin and Hirscher appear to have acquired the elements of Biotensegrity. Assuming a group of racers of equal athletic ability, the odds will favour those whose stance is based on Biotensegrity.
In a ski stance based on bio-tensegrity, tension in the arches of the feet extends to from the balls of the feet to the palms of the hands holding the poles.
- Start by standing barefoot on a hard flat floor or surface in a controlled environment such as your home. Where possible, use the same surface and place to rehearse the stance. If you have constructed a dynamic ramp assessment device, use this with the top plate set to level.
- Stand upright at attention. You should feel most of the weight under your heels and less weight across the balls of your feet. This is normal. The fore-aft weight distribution is actually 50-50 heel to forefoot. But because the weight of the body is spread across the balls of the feet and along the outer aspect behind the small toes, more weight is sensed under the heels. Stand so your weight is distributed equally between both feet.
- Relax your hamstrings (in your thighs) and let your torso drop towards the floor. Your knees will move forward as they flex and your ankles will dorsiflex. Your ankles should stop dorsiflexing on their own when the front of your knee caps are aligned approximately over the balls of your feet. This is the point where the tension in your soleus (calf muscle) peaks with the tension in plantar ligament of your arches. You should feel about the same pressure under the balls of your feet as you feel under your heels. But it should feel as if the circle of pressure under your heels has gotten bigger and your feet are more connected or integrated with the floor. I call this ‘rooted’ because it should feel as if your feet have sunk into the floor.
- While keeping your upper body erect, move slightly forward in the hips. You will quickly reach a point where you start to become unstable and feel as if you would fall forward onto your face if you moved farther forward in the hips. When you get to this point your big toes should press down on the floor on their own to try stabilize you. This is the forward limit of stability.
- Now move rearward in the hips until you start to feel the same instability. This is the rearmost limit of stability.
- Now bend forward from the waist. Do not curl your back. Bend from the hip sockets for the thigh bone (femur). This movement is actually thigh flexion. Lift your thigh to get the right feeling. As you bend forward from the waist, your buttocks will move rearward and upward as your ankles and knees straighten. Reach forward with your arms as if you were going to hug a large barrel in front of you. Make sure the palms of your hands are facing each other with fingers curled and pointing towards each other.
- Find the place where your arms and head feel neutral to your spine. As your arms come into position you should feel your abdominal core and muscles in your back acquire tension. Slings Isometric stance
- Experiment by moving forward and rearward in the pelvis. As you move forward in the pelvis the pressure should increase under the balls of your feet. But you should not feel unstable. If anything, you should feel stronger and more stable. You should feel as if the weight of your head and shoulders is pressing your feet down into the floor.
- Increase the bend at your waist while keeping the pressure on the balls of your feet and heels until the top of your head is down by your knees. You should still feel very strong and stable in the feet. This is the lowermost limit of waist flexion.
Once you have acquired a kinesthetic sense of the bio-integrity of foot to hand tension, a sense of stability while pulsing the torso vertically up and down over the feet confirms a state of bio-tensegrity.
The photo below is of simple model I designed and constructed in 1993 to illustrate the basic concept of bottom up Biotensegrity and how the degree of passive tension in the plantar ligament of the arches of the feet and the vertical biokinetic chain is driven by the compression from weight of COM stacked over the foot.
In my next post I will discuss what I term the NABOSO Effect.