Armboard assemblies for supporting and positioning a limb relative to a mounting structure

An armboard assembly includes an armboard deck including a cavity formed in a lower surface of the armboard deck, an armboard mount including a plurality of radially extending teeth positioned within a mount portion of the cavity, and an engagement assembly movable relative to the armboard deck between an engaged position to engage the plurality of teeth of the armboard mount and a disengaged position to disengage the plurality of teeth of the armboard mount. The engagement assembly includes a handle including one or more legs extending from an upper surface of the handle, which engage an insertion hole formed in the armboard deck and a channel extending from the insertion hole toward the armboard mount, and an indexing member positioned within the cavity of the armboard deck and coupled to the handle. The indexing member limits movement of the engagement assembly by maintaining the legs within the channel.