Axillary nerve
The shoulder nerve that powers the deltoid muscle; one injury of it is documented in a 2023 case series of rope bondage nerve injuries, after a suspension from the torso.
MedlinePlus explains that the axillary nerve controls the deltoid, the shoulder muscle that lifts the arm away from the body, and supplies feeling to the skin around it. Damage can come from direct injury, long-term pressure, entrapment, shoulder dislocation and other shoulder injuries. Typical signs are numbness over part of the outer shoulder, shoulder pain and weakness when raising the arm to the side. The encyclopedia adds that some people recover without treatment and that recovery can take many months. In the 2023 Cureus case series on rope bondage nerve injuries, one of the sixteen injuries involved this nerve: it followed a suspension from the torso, in which pressure on the shoulders and their overextension affected the nerve, and left the person unable to lift the arm sideways.