This invention discloses a foot clamping structure of an inversion table machine, comprising a foot bar, a fixed foot sleeving set fixedly connected to the foot bar, an adjusting seat, a movable foot sleeving set fixedly connected to the adjusting seat, a pivot axle, an elastic positioning unit and a positioning axle, wherein the foot bar is provided with a pivot hole and a positioning groove and the positioning groove is provided with a movable region and a plurality of positioning regions which are communicated with the movable region and are spaced apart with a preset distance the adjusting seat is provided with a pivoting elongated hole and a positioning elongated hole the pivot axle penetrates through the pivoting elongated hole and the pivot hole the elastic positioning unit is arranged on the adjusting seat, can be reciprocally displaced between a positioning position and an adjusting position, and is provided with a coupling hole the positioning axle penetrates through the positioning elongated hole, the coupling hole, and the positioning groove and is coupled by the elastic positioning unit. During inversion of the foot bar, the adjusting seat is downwards moved along the pivoting elongated hone and the positioning hole is not overlapped with the movable region at the moment, so that the positioning axle cannot be moved from the positioning regions to the movable region and the adjusting seat cannot pivot relative to the foot bar, so as to achieve the effect of better safety.一種倒立機之夾腳結構,包含有一腳桿、一固接於該腳桿上之固定腳套組、一調整座、一固接於該調整座上之活動腳套組、一樞接軸、一彈性定位單元及一定位軸;該腳桿具有一樞孔及一定位槽,該定位槽具有一活動區及若干連通該活動區並相隔預定間距之定位區,該調整座具有一樞接長條孔及一定位長條孔,該樞接軸穿經該樞接長條孔與該樞孔,該彈性定位單元設於該調整座上,並可於一定位位置至一調整位置間進行往復位移,該彈性定位單元具有一連動孔,該定位軸穿經該定位長條孔、該連動孔及該定位凹槽,該定位軸受該彈性定位單元所連動;當該腳桿倒立時,該調整座沿著該樞接長條孔下移,該定位長條孔此時未與該活動區重疊,該定位軸便無法自該定位區移動至該活動區,使該調整座無法相對該腳桿進行樞轉,以達到安全性較佳之功效。100‧‧‧倒立機之夾腳結構10‧‧‧腳桿11‧‧‧樞孔12‧‧‧定位板121‧‧‧定位凹槽122‧‧‧活動區123‧‧‧定位區20‧‧‧踏板30‧‧‧固定腳套組31‧‧‧固定桿32‧‧‧固定腳套40‧‧‧調整座41‧‧‧樞接長條孔42‧‧‧定位長條孔43‧‧‧位移長條孔50‧‧‧活動腳套組51‧‧‧活動桿52‧
