Derivational etymology starting from the noun ἴς, ἰνός in the meaning "strength". From it is derived a verb *ἰνέω (explicit in the Etym. Magnum, see Parallels) and then by adjunction of [k], κινέω "to move, to set in motion". The interesting element is the semantic justification given at the end: motion is specific to healthy and valid people (δυνάμενος and ἀδύνατος refer here to physical capacity of motion), and so is strength. Motion is a consequence of strength, so to speak. The explanation matches the middle κινέομαι, not the active κινέω "to move sth." (transitive), displaying the usual indifference to diathesis of Greek etymological explanations.