The Alien Series Leg Extension / Leg Curl ndi makina opangira ntchito ziwiri. Zopangidwa ndi shin pad yabwino komanso pad ankle, mutha kusintha mosavuta kuchokera pakukhala. Mpando ndi pad kumbuyo zakhala zokongoletsedwa ndi ergonomically kuti zithandizidwe bwino komanso kutonthozedwa. Ndipo shin pad, yomwe ili pansi pa bondo, idapangidwa kuti izithandizira kupindika kwa mwendo, potero kuthandiza ogwiritsa ntchito kupeza malo oyenera ophunzitsira masewera olimbitsa thupi osiyanasiyana.