Usually use a ruler to hit the hand board. It hurts to hit the palm of your hand until it is swollen. It's not easy to hit the right hand. You should hit your left hand, so you can hit hard and don't care about the injury until it swells up. There are three stages: dividends, swelling and purple.

1 Stretch your palm upward, take off your gloves, first hit the palm 30 times with a ruler, and hit the palm from tender to crimson with the greatest strength. At this time, the palm will turn red, which is also the most painful time to wait, burning pain.

Then hit it 80 times with a ruler and enter the swelling stage. At this time, the hand board will swell up, and the palm muscles will feel swollen and stiff. Because the palm is numb, it doesn't hurt so much at first.

At this time, the ruler is not easy to use, because I don't need to use the board when it is swollen, and it doesn't hurt when I am numb, so I will use rattan to hit the hand board, up to 90 times. This is the stage of playing blue, and the muscles under the thumb turn dark purple, which will obviously swell very high, and then turn blue. At this time, there is an obvious contrast between the fingers and the palm. The fingers are slender, the hand plate is swollen, the fingers are white, and the lower part of the thumb on the left side of the palm is blue.