Umphambili ufumana amandla okubetha, asasazwa yi-bumper engaphambili ukuya kwiibhokisi zokufunxa amandla kumacala omabini aze adluliselwe kumzila ongaphambili osekhohlo nasekunene, aze emva koko aye kulo lonke ulwakhiwo lomzimba.
Umva uchatshazelwa ngamandla ombane, kwaye amandla ombane adluliselwa yi-bumper yangasemva ukuya kwibhokisi yokufunxa amandla kumacala omabini, ukuya kumqolo wangasemva wasekhohlo nasekunene, uze emva koko uye kwezinye izakhiwo zomzimba.
Iibhampa ezithintela umoya ezinamandla aphantsi ziyakwazi ukumelana nokuchaphazeleka, ngelixa iibhampa ezithintela umoya ezinamandla aphezulu zidlala indima yokudlulisela amandla, ukusasazwa kunye nokubopha, kwaye ekugqibeleni zidluliselwa kwezinye izakhiwo zomzimba, zize zixhomekeke kumandla esakhiwo somzimba ukuze zikwazi ukumelana nawo.
IMelika ayithathi i-bumper njengoqwalaselo lokhuseleko: I-IIHS eMelika ayithathi i-bumper njengoqwalaselo lokhuseleko, kodwa njengoncedo lokunciphisa ukulahleka kokungqubana ngesantya esiphantsi. Ke ngoko, uvavanyo lwe-bumper lusekwe kwingcamango yendlela yokunciphisa iindleko zokulahleka kunye nokugcinwa. Kukho iintlobo ezine zovavanyo lwe-IIHS lokungqubana kwe-bumper, oluvavanyo lokungqubana kwangaphambili nangasemva (isantya se-10km/h) kunye novavanyo lokungqubana kwangaphambili nangasemva (isantya se-5km/h).