Slackness of the ancestral sinew

1. An etiological factor of crippling wilt. Plain Questions (素问 sù wèn, wěi lùn) states, When yáng brightness (yáng míng) is vacuous, then the ancestral sinews are slack, the girdling dài vessel fails to conduct; hence the legs become wilted and useless.

2. Impotence. Plain Questions (素问 sù wèn, wěi lùn) states, When the ancestral sinew is slack, sinew wilting develops.