Tendons (Latin
tendo) join muscle to bone — but they can also attach to
fascia, and tendon, fascia and the organic substance of
bone consist primarily of the same
type I collagen. The continuum customary in Yiquan — “skin, flesh, tendons, bone”, along which the first level of
Mo Jin gropes — therefore describes differently condensed forms of one building material, not four separate tissues. For training, two properties count. The tendon is a
spring: the Achilles tendon contributes up to 35 % of the energy return, and in the push-off phase almost all the stretch energy comes back. This gives the image of the body as “one elastic tendon” (
Song/Jin) a physiological counterpart — and gives
Fa Li a store. And it is
trainable, but slow: twelve weeks of isometric training raise tendon stiffness by around 57 %, with the
duration of the hold being decisive — only 20-second holds worked, one-second impulses did not. It becomes measurable only after about two months, because collagen turns over more slowly than muscle protein. Long sustained loading is therefore the effective stimulus — which is what
Zhan Zhuang does. With the reservation that the studies work at 70–90 % of maximal force while standing is low-intensity — the form of contraction and the duration match, the intensity does not. As a sense organ the tendon carries the
Golgi tendon organ, which measures
tension, while the muscle spindle of the
musculature measures length — and for
Ting Jin, tension is the decisive quantity (→
proprioception). That tendons have few blood vessels and therefore
regenerate poorly gives the maxim “slow and fine, never hurried” a solid justification.
Anatomical background, not a Yiquan term
The tendon connects muscle to bone; exceptions are intermediate tendons between two muscle bellies and attachments to fascia. It consists of collagenous fibres — mainly collagen type I — in dense connective tissue. Flat muscles end in aponeuroses, others in cord-like tendons; the Achilles tendon withstands over a tonne of tensile load.
As with fascia: this is background, not doctrine. Two findings, however, bear directly on training.
First: they are not four separate things
Tendons can also attach to fascia, and both consist primarily of collagen type I — as does bone, for 95 percent of its organic substance. This gives the tissue continuum customary in Yiquan — “skin, flesh, sinews, bone” — a material basis.
These are not four separate materials but differently condensed forms of the same one. The classical enumeration therefore describes not categories but a gradient.
Second: tendons regenerate poorly
Tendons contain few nerves and blood vessels, from which a poor capacity for regeneration follows. Tendon tissue forgives overload less readily than muscle does.
This is the practically most important point on this page. The slowness emphasised throughout Yiquan — slow and fine, no haste — and the warning against forced practice are therefore not a matter of style, nor a test of patience. They have a concrete basis in the tissue: what is being trained here builds more slowly, and heals more slowly, than what one first feels in training.