(not Efficiently Anyways...lemme Explain:
Link #no because you wouldnt be able to run #(not efficiently anyways...lemme explain: #the gluteus maximus muscle (great name #when you walk up stairs youre working your glutes #so yeah long story short: #if your asscrack was sideways #but you were still bipedal #you would not run down the stairs #you would fall down the stairs #though i suppose that might result in a thunderous clap