Inoratidzira yakasarudzika inogadziriswa back pad iyo inobvumira vashandisi kuti vasarudze huwandu hwekufamba hunonyatsokodzera zvavanoda ivo pachavo nekushandura yakachinjika ruoko chinzvimbo maererano nemapfudzi. Ichi chakasarudzika chimiro, chakasanganiswa neunilateral compression ruoko musangano pamadhigirii makumi maviri kumusoro uye pamberi pemushandisi uye maviri mabatiro, inobvumira yakazara yakazara yekufamba kudzidziswa pasina kukanganisa.
Chigaro chinogona kugadziriswa pawakagara kana kumira, uye chinobatsirwa nepamusoro-soro mutsara mabhengi uye macylinders ekugadzikana, kuderera-kukanganisa kugadzirisa.
Iyo unilateral compression maoko inoshandura 20 madhigirii kune rumwe rutivi kumusoro uye pamberi pemapfudzi, ichibvumira kuzara kwakazara kwekufamba pasina kukanganisa.
Iyo yakasarudzika inogadziriswa kumashure inobvumira mushandisi kuti achinje chinzvimbo cheiyo horizontal mubato nemapfudzi.