Walking (also known as ambulation) is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step. This applies regardless of the number of limbs - even arthropods with six, eight or more limbs.

The word walk is descended from the Old English wealcan "to roll". In humans and other bipeds, walking is generally distinguished from running in that only one foot at a time leaves contact with the ground and there is a period of double-support. In contrast, running begins when both feet are off the ground with each step. This distinction has the status of a formal requirement in competitive walking events. For quadrupedal species, there are numerous gaits which may be termed walking or running, and distinctions based upon the presence or absence of a suspended phase or the number of feet in contact any time do not yield mechanically correct classification. The most effective method to distinguish walking from running is to measure the height of a person's center of mass using motion capture or a force plate at midstance. During walking, the center of mass reaches a maximum height at midstance while during running, it is at a minimum. Definitions based on the percent of the stride during which a foot is in contact with the ground (averaged across all feet) of greater than 50% contact corresponds well with identification of 'inverted pendulum' mechanics and are indicative of walking for animals with any number of limbs, although this definition is incomplete. Running humans and animals may have contact periods greater than 50% of a gait cycle when rounding corners, running uphill or carrying loads.

James Todd Smith (born January 14, 1968), better known as LL Cool J (an abbreviation for Ladies Love Cool James), is an American rapper, entrepreneur, and actor from Bay Shore, New York. He is known for romantic ballads such as "I Need Love", "Around the Way Girl" and "Hey Lover" as well as pioneering hip-hop such as "I Can't Live Without My Radio", "I'm Bad", "The Boomin' System", and "Mama Said Knock You Out". He has released thirteen studio albums and two greatest hits compilations, including 2008's Exit 13, the last for his record deal with Def Jam Recordings. He has also appeared in numerous films, and currently stars as NCIS Special Agent Sam Hanna on the CBS crime drama television series NCIS: Los Angeles.

As he grew older, Smith found a way to escape the effects of his abuse, and his bullying attitude: hip-hop music. He fell in love with it at the age of nine, and by 11 he was writing lyrics and making his own songs with some DJ equipment his grandmother gave him to stop him riding motorcycles or doing karate. Before too long, LL was an established member of the Hip-Hop community in his area. He gained notoriety through his many rap battles against well-established MCs, including the battle against Chicken and Porn that rocketed him to fame.

Mark Kermode (born 2 July 1963) is an English film critic, musician and a member of the British Academy of Film and Television Arts. He contributes to Sight and Sound magazine, The Observer newspaper and BBC Radio 5 Live, where he presents Kermode and Mayo's Film Reviews with Simon Mayo on Friday afternoons. He also co-presents the BBC Two arts programme The Culture Show and discusses other branches of the arts for the BBC Two programme Newsnight Review. Kermode writes and presents a film-related video blog for the BBC.

Kermode, born Mark Fairey in Barnet, North London, England, attended Haberdashers' Aske's Boys' School, an independent boys' school in Elstree, a few years ahead of comedians Sacha Baron Cohen, Matt Lucas and David Baddiel and in the same year as actor Jason Isaacs. He was raised as a Methodist, and is now a member of the Church of England.

Mark Fairey's parents divorced when he was in his early 20s and he subsequently changed his surname to his GP mother's maiden name by deed poll. (Neither of them is related to the literary critic Frank Kermode.)