Origin and history of valgus

deformity in which the feet are extroverted, so that the inner ankle rests on the ground, while the sole of the foot is more or less turned outwards, 1800, from Latin varus "bent, bent outwards, turned awry, crooked," specifically "with legs bent inward, knock-kneed," a word of uncertain origin (see vary).

If the original meaning was 'with the legs opened', varus might be compared with vanus and vastus, and reflect *wa-ro- 'going apart, letting go'. In any case, none of the other etymologies proposed seems plausible. [de Vaan]

The use of classical varus and valgus, which denoted deformities of the legs, in modern medicine to describe deformities of the feet, was criticized by learned writers (see "Edinburgh Medical and Surgical Journal," July 1838).

"travel on foot," c. 1200, walken, a merging and sense-shift of two verbs: 1. Old English wealcan "to toss, roll, move round" (past tense weolc, past participle wealcen), and 2. wealcian "to roll up, curl." Both are from Proto-Germanic *welk- (source also of Old Norse valka "to drag about," Danish valke "to full" (cloth), Middle Dutch walken "to knead, press, full" (cloth), Old High German walchan "to knead," German walken "to full"), and perhaps ultimately from PIE root *wel- (3) "to turn, revolve."

The shift in sense is perhaps from a specialization of the Old English word via the notion of "be in motion," or via walk (v.) in a sense of "to full cloth" (by treading on it). This sense in English is not attested earlier than the meaning "travel on foot," unless it explains the surname Walker.

It is attested by c. 1400 as "to pace" (a room, the floor). By mid-14c. as "walk for purposes of recreation, exercise, solitude, etc." In a 13c. bestiary it is used of snakes. Also in Middle English of the passage of time and in 15c. of wheeled carts. "Rarely is there so specific a word as NE walk, clearly distinguished from both go and run" [Buck].

By c. 1300 as "behave, act, or live in a certain manner," frequently in a religious sense (walk with God) and translating Latin ambulare. By early 14c. in reference to an unquiet spirit or the resurrected dead, "move about on earth." By c. 1600 as "act in one's sleep, sleepwalk."

It was used by mid-14c. figuratively, of abstract things (fear, plague, etc.), in a sense of "be at work, be present and active." To walk among "be with, be company with" is from late 14c. 

The transitive meaning "move through or over by walking" is from c. 1300; that of "cause to walk, lead, drive," especially "exercise a dog (or horse) by walking" is from late 15c.

The meaning "to escort (someone) on a walk" is from 1620s. The meaning "move (a heavy object) by turning and shoving it in a manner suggesting walking" is by 1890. The colloquial sense of "depart, leave, walk away," is mid-19c., but it had been used long before as "proceed, go, depart" (early 14c.) and "go away" (mid-15c.).

A walk-off (n.) as "an act of walking off" is by 1936 in stage jargon. To walk it off, of an injury, cramp, etc., is from 1741. Related: Walked; walking.