When you think of karate as budo, each time you fight or spar, you have one chance, no second, you must develop a technique that is finishing blow, where the whole body integrate to produce maximum force in shortest amount of time, at one direction.
Through the generations we in karate, developed systematic methods, not found in any sport to such details, and all as result of experience and necessity, without sophisticated high tech.
If you think of reaching and touching, or making a point, than you develop as Sensei Nishiyama used to call it “picking oranges technique), where it is sufficient to touch the opponent with the hand or foot. If the goal is for the hand to reach the target as quick as possible, than the systematic method we develop in Budo karate to use the body as a whole is counter productive.
Sensei Nishiyama used to scold us “no scratching techniques” and “if you do scratching techniques, you just make it more dangerous for yourself”, “best fight is no fight” but “if you fight you must finish”
Totally different kind of training is required for Budo and sport karates, even though same karate form is being used.
If we look at the budo technique and the sport karate technique from a point of view of physical therapy and movement to prevent injuries or to rehabilitate, it is well recognized today that the most important factor in keeping the body functioning effectively and healthy is sequence of activation of muscles or proper nervous system patterns.
The top physical therapist will confirm that every action should be a chain reaction from the ground up, and in addition in every action the deeper stabilizers muscles should fire first and than the outer prime movers.
proper sequence of activation is only possible out of balance musculature, balance between flexors and extensors, in other words optimal posture.
Sequence of activation and optimal posture are closely related and affect each other.
If I throw a ball or execute a reverse punch, both movements require rotation and arm extension. In optimal sequence of movement, the feet will fire first using ground reaction, force will transfer through the legs, through the sacrum (body center), through the thoracic spine through the scapula and than shoulder joint and arm extension.
In a head forward posture, thoracic spine rotation might be limited which will cause access motion in the scapula and shoulder joint.
Even if one has good posture, but have bad habit due to wrong coaching, or image of the movement, one might move at the shoulder independently from the scapula, thoracic spine and ground reaction, and will eventually create bad posture.
In both cases wrong patterns will create inefficient movement, bad postures, and wear and tear at the shoulder.
This scenario can be seen anywhere along the kinetic chain.
Limitation in foot pronation can create compensation along the kinetic chain, such as in the lumbar spine or shoulder.
It is just one example how the benefits of karate lies in its budo aspect.