Other methods to develop pressure and contraction at kime
At the moment the partner makes kime, let’s say in gyaku zuki, I check his contraction, and for areas that are contracting insufficiently, by tapping on the partner by doing so bringing his/her awareness to those muscles. Some muscles typically are hyperactive and have low threshold such as the hip flexors, hamstrings, lumbar erectors and chest muscles, other muscles have high threshold and tend to be underactive and even dormant, such as the gluts, lower abdominals and scapula adductors.
First, I will push against his fist to see that total contraction is to technique direction, than I will tap the connecting muscles, such as under the armpit (chest and back), if the shoulders are raised because of upper trapezius dominance than the lattisimus will be over lengthened and hard to engage. Than the areas that are most commonly lazy and underactive, such as the back around the thoracic spine, between the scapulas, this area is underactive in people with forward head posture in particular. I will point the relationship between posture and muscles that don’t fire properly, for example in a head forward posture, thoracic kyposis is exaggerated and the back extensors and scapula adductors are over lengthened and not in optimal length for function, also the muscles around the shoulder joint are not in optimal length and movement at the shoulder is altered. We need to fix the posture and bring the attention to those areas. I will also point out the relationship between weak hikite (pulling hand), and under active back, when the hikite is firm, glued to the body and the elbow is heavy, the back muscles will likely fire and engage, the arm feeds the back.
Than I will check the buttocks and inner thighs and abdomen. The gluts tend to be under active when its antagonists hip flexors, or its postural synergists, hamstrings and/or the lumbar erectors are tight and the pelvis anteriorily tilts.
Touching your partner can be a great feedback to the partner, bring the awareness and also adjust the alignment that allows for optimal muscles length for contraction.
Making kime without action space
Put your fist on your partner stomach in gyaku zuki position and use sharp pressure to floor and contraction from the inside out to drive your partner back, do not push or over extend. The pressure to floor and contraction are controlled by the breath. Your partner should strongly tighten the abdomen and core.
A skillful person can produce sufficient shocking power without or with very little external motion.
We have to teach the nervous system to recruit as many motor units as possible in shortest time and in proper sequence.
Similar exercise but with added reaction component is to face an opponent with hands touching, and as the opponent punch block sharply and without external action, snap his attack away using sharp pressure and contraction from around the spine muscles. Both the reaction and action are initiated by the breath. Make sure that the blocking arm barely moves, the whole body from the ground integrate to snap the opponent attack away, don’t push, and be relax to allow space for contraction.