Some science behind the scenes
In the diagram to the right, you can see the recti abdominis, the tough muscle pair forming the anterior wall of the abdomen.
They arise from the pubes and insert on the fifth sixth and seventh ribs. As this is too great a length for a single muscle to span for effective control, three insertions of fascia material reduce the length and strengthen the muscle.
If anything happens to these muscles or the fascia, [repetitive flexing, blow, surgery, virus attack etc] the effect may be to shorten and thicken the overall structure.
It may seem bizarre, but many physical training exercises such as push ups and sit-ups that apparently strengthen the stomach muscles actually only serve to permanently shorten and stiffen the recti.
This chronic shortening will drag down the rib structure as a whole bringing the lower ribs too close to the pelvic brim. It will have an effect on the whole body, as it will also strain the neck and cervical spine which are included in the compensation. The myofascial structures of the cervical spine become anteriorly shortened and result in the head coming forward.
The sag of the ribcage strains the 3 or 4 uppermost ribs as well. There will be pain in the ribs. Tenderness and general aches result. In turn the ventral sag in the first and second ribs displaces and raises the first dorsal vertebra in the back. And as a result we get the beginnings of the so called 'dowager's hump – see left.
Muscles act as pumps moving food and oxygen carrying fluids to and from cells, so exercise of a moderate sort is beneficial. But very repetitious specific movement can in the longer term simply 'harden' the muscle and it loses flexibility and all its pumping functions. It also, all too frequently, shortens the muscle and contributes to a wasting of the psoas of which more in a moment.
Flesh and fat in any area of the body tend to collect in response to biological laws. Wherever an insecure area is under consistent strain, flesh tries to ensure greater stability by enwrapping or splinting it.
In this case if the problem is treated and the anterior ribcage is freed through greater length and greater elasticity in the recti, strain on the upper backbone lessens. The junction of cervical and dorsal vertebrae then need no longer be splinted and protected by mass flesh. And the hump disappears.