Hanging is asphyxia due to constriction of neck as a result of suspension in such a manner that the weight of the body or a part of the victim's body pulls upon the ligature. The factor of suspension differentiates hanging from strangulation by ligature, the later being caused by the application of a ligature to the neck in such a way that the force acting upon it is other than the weight of the body. Both, in hanging and ligature strangulation, a ligature mark may be produced by local damage to the skin of the neck due to pressure that may be associated with lateral rubbing action resulting in associated abrasion. This ligature mark on the neck is of crucial diagnostic importance and requires detailed inspection with regard to its course, depth and width. Sometimes the groove retains the pattern of the ligature material(as for example, a spiral weave of rope).
The ligature mark appears as a furrow on the skin whose direction is determined by the point of suspension(knot). Depending upon the duration of suspension, the furrow is initially pale or yellow parchment, like area with a rim that is congested or with slight punctiform haematomas. With time, the furrow dries & becomes brownish. The narrower the ligature and the harder its material, the more detectable is the ligature mark on the skin.
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