Nkọwa ngwaahịa:
1.Ọ nwere ike itinye ya na ọnọdụ ọ bụla nwere oghere na ịdị elu kwesịrị ekwesị.
2.nwere ike mezue ọzụzụ anụ ahụ dị iche iche na barbell.
3.It na-onwem na transverse na longitudinal bearings, nke mere na ọ nwere ike bugharia 180 ° transverse na longitudinal.
