Hand-held instruments have an actuator assembly which may be employed to actuate a distally mounted tool by application of radial force about the entirety of the instrument circumference (i.e., is omni-actuatable). Most preferably, the actuator assembly (10-1) includes a plurality of circumferentially spaced-apart generally L-shaped actuator levers (20) defining respective arcuate bearing surfaces (22-1) along exterior edge regions thereof, and a retaining ring (22) which circumferentially bounds the actuator levers around the exterior edge regions thereof. The retaining ring most preferably defines an interior stationary arcuate guide surface (20-3) in conformable mated relationship to the bearing surfaces (22-1) of said actuator levers. Radial force applied to the proximally extending arm sections of the levers thereby responsively causes the bearing surfaces thereof to be slideably moved along the guide surface of said retaining ring so as to translate such radial force into longitudinal movements of an elongate actuation pin (18) between retracted and extended positions thereof. By providing a tool which operatively coacts with the actuation pin, a surgeon may actuate the tool as needed by applying radial force at any point about the circumference of the actuator assembly.Linvention concerne des instruments manuels comprenant un dispositif dactionnement utilisé pour actionner un outil monté distalement par application dune force radiale sur la globalité de la circonférence dudit instrument (par exemple, omni-actionnable). De préférence, le dispositif dactionnement (10-1) comporte une pluralité de leviers dactionneur en forme de L généralement espacés circonférentiellement (20) qui forment des surfaces de support arquées respectives (22-1) le long des zones correspondantes de bords extérieurs, et un anneau de rétention (22) liant circonférentiellement lesdits leviers autour des zones correspondantes de bords extérieurs. Cet anneau de rétention constitue, de préfé
