A variety of Kāyakleśa (external austerity by undertaking yogic postures);
a Yogic posture simulating a stick, in which the practitioner lies down on the ground in a straight position like a bamboo by joining both legs and touching both hands to the legs.
daṇḍāyatikaḥ - prasāritadehaḥ.
(Sthā 7.49 Vṛ Pa 378)