Body grips to co-workers: tradition or abuse?

Lately in the office, my boss seems to greet everyone of his co-workers with different body grips occasionally. To women, he grips their arms. In men, he squeezes the muscles beside the neck. One time he squeezed mine I asked him if it was custom in his nature to greet (yes. He greets a 'how are you' when he does that) his employees with those hurtful grips. He says it is to make people awake, then he talks that he get the idea from a massage technique. Even the other guy imitates the boss' 'buddy' grip.

Is it a custom or tradition to several people to inflict body pain to his co-workers? Not that I'm only asking this at work, but I do meet a lot of people outside work who also does that several body grips that I thought maybe it really was a normal greeting or sign of accepting their friendship with them.