Ever see the video of George W. putting his hands on German Chancellor Angela Merkel's shoulders from behind in an inappropriately familiar manner, and she shrugs him off in an instinctive near-seizure of disgust? I appreciate your hesitation to make an issue of your situation in HR, but if you consistently physically recoil from unwanted contact as if your coworkers' hands were causing you physical pain of intensity equal to your level of emotional discomfort, people might learn to keep their hands off you.