The word "踢腿" is formed by combining the character "踢", meaning to kick, which itself incorporates the radical "足" for foot to indicate the action, with the character "腿", meaning leg, which uses the radical "月" to signify a body part; together they create a verb-object compound where the action of kicking directly relates to the leg, resulting in a term that denotes the specific movement of kicking with the leg.