Natyashastra
त्यक्त्वा (कृत्वा?) समपदं स्थानमश्वक्रान्ते तथैव च । स्याद्विक्लवादिष्वर्थेषु त्र्यश्रः पादो यथाविधिः ॥ २७२॥
Leaving or placing the feet evenly in the posture called Ashvakranta, the tryashra foot is used appropriately in cases like lameness and others.
english translation
tyaktvA (kRtvA?) samapadaM sthAnamazvakrAnte tathaiva ca । syAdviklavAdiSvartheSu tryazraH pAdo yathAvidhiH ॥ 272॥
hk transliteration by Sanscript