Hypnic jerks commonly occur just as we are nodding off; there is a sudden sensation of falling or stumbling, and we jerk ourselves awake. Myoclonic jerks are similar, but can occur whilst we are fully conscious. Both are caused by the involuntary movement of muscle groups.
Because the movement is involuntary, it may feel as if we have been pushed, prodded or shoved by an external force. It is this aspect that may lead to a connection with ‘paranormal’ activity. People may be drawn to assume they have been touched by invisible entities, when in fact the cause of the experience is an internal, bodily reaction.