Ali bin Abi Taalib Radiyallahu 'Anhu' says:
"When Rasulullah Sallallahu Alayhi Wasallam walked he bent slightly forward as if he was descending from a high place".This has been explained in the previous ahaadith. (ID)
English reference (ID): Book 18, Hadith 118 (ID)
Arabic reference (ID): Book 19, Hadith 125 (ID)