주먹 꽉쥐고 손바닥이랑 팔목 사이를 꾸욱 하고 누르면 손목에 왠 공같은게 올라오는거있잖아요... 막 어떤사람은 하나만 올라오고 어떤 사람은 여러개 올라오고... 그거 왜 그러는거죠...? 이상한 콩알만한 크기가 손목에 뿅뿅 하고 올라오는게 신기하긴한데 항상 궁금했어요... 왜죠...?