The joint reaction force




It is always good that we pay attention to the floor reaction force. This force is nature, and it is always there on the earth. All we need is to realize it. However, this is not enough for better. There is another reaction force in the gravitational field, the joint reaction force, and this is the key.

Something we, human-being, need to manage voluntarily is our body’s placement (both the whole body and the parts of the body). In other word, this is the angle of the whole body in relation to the feet on the ground or the angle of the axial bones in relation to the axial bone below. This affects both the pattern and the degree of the muscular contraction for supporting the bones (and the body). As a result of this, the pattern generating the joint reaction force will be changed. More muscle contraction is involved for generation of the bone reaction force (i.e. for the support of the bones), if the angle of the axial bones is not adequate.

This may not be nature. I mean that the angle of the bones may not be managed well automatically (Especially for adults. Adults easily forget what we need to do for keeping better condition.) And, more muscles contraction is easily involved for the generation of the joint reaction force.

So, to make freer neck (minimum supporting condition, less muscle tension), we need to manage them. One of the key actions is the placement of the head. This is because it affects the angle of the spinal columns. FM has found this. I would say there are some other key actions. One of them is the angle of the pelvis. If the pelvis is not in advantageous angle, we won’t be in the best free neck condition. In this condition I feel like I lose the floor reaction force in the middle of the body and cannot receive it well in the upper body including the neck part. We still get the floor reaction force and the joint reaction force through the axial bones in this condition. (If we don’t, it means we fall down.) However, if we generate this joint reaction force with more muscle contraction, we would feel like we lose the floor reaction force, or just simply “lose support”. 

To adapt well in the gravitational field, we had better pay attention to the joint reaction force (put it more precisely, the factor generating the bone reaction force) as well as the floor reaction force. In other word, we had better pay attention to the angle of the bones to adapt well on the earth.









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Paul AokiIf you are interested in my lesson approach, please contact me. There is a form in the linked page, and please contact me through it. Just questions are welcome.


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