▁The ▁dog ' s ▁weight , ▁however , ▁is ▁not ▁supported ▁by ▁the ▁feet ▁in ▁the ▁sequence ▁of ▁the ▁single ▁susp ension ▁gal lop . ▁ ▁Just ▁after ▁taking ▁off ▁from ▁the ▁L F ▁and ▁just ▁after ▁taking ▁off ▁from ▁the ▁R F ▁susp ension ▁occurs . ▁This ▁is ▁the ▁only ▁g ait ▁in ▁which ▁a ▁dog ▁is ▁in ▁full ▁extension . ▁ ▁The ▁front ▁legs ▁are ▁in ▁full ▁extension ▁forward ▁while ▁the ▁rear ▁legs ▁are ▁in ▁full ▁extension ▁rear ward . ▁ ▁Additionally , ▁the ▁dog ' s ▁back ▁is ▁fol ded ▁and ▁att ains ▁maximum ▁over re ach , ▁or ▁where ▁the ▁rear ▁feet ▁extend ▁in ▁front ▁of ▁the ▁front ▁feet ▁and ▁the ▁front ▁feet ▁extend ▁behind ▁the ▁rear ▁feet . ▁ ▁When ▁the ▁feet ▁pass ▁each ▁other , ▁the ▁front ▁feet ▁are ▁inside ▁of ▁the ▁rear ▁feet . ▁ ▁A ▁dog ▁uses ▁its ▁back ▁to ▁att ain ▁speed . ▁The ▁back ' s ▁most ▁flexible ▁point ▁is ▁just ▁over ▁the ▁lo in ▁area , ▁and ▁the ▁t uck - up ▁allows ▁for ▁the ▁fol ding ▁of ▁the ▁under ▁portion ▁of ▁the ▁dog ' s ▁body . ▁The ▁rear ▁legs ▁over re ach ▁on ▁the ▁outside ▁of ▁the ▁front ▁legs . ▁Ess ential ▁for ▁a ▁fast ▁dog ▁is ▁the ▁ability ▁to ▁flex ▁its ▁back ▁from ▁a ▁straight ▁position ▁to ▁an ▁arch ed ▁position . ▁ ▁A ▁permanent ▁arch ▁is ▁inf lex ible ▁and ▁is ▁considered ▁a ▁serious ▁fault . ▁The ▁double ▁susp ension ▁gal lop ▁is ▁a ▁le aping ▁g ait