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. (ES)
English reference (ES): Book 18, Hadith 118 (ES)
Arabic reference (ES): Book 19, Hadith 125 (ES)