When lifting dumbbells and pushing shoulders while sitting, you should pay attention to the following points:

1. Select dumbbells with appropriate weight.

2. Choose a stool with a backrest, take a sitting posture, put your feet on the ground with your legs apart, hold your chest and abdomen and look forward.

3. Hold the dumbbell in each hand and put it on the edge above the shoulder, with the palm facing forward.

4. Keep your body stable. Push the dumbbell upward with the deltoid muscle and stop when the arms are close to the straight state (unlocked). Keep the peak contraction 1 sec, and don't let the dumbbells collide. Then slowly put down the dumbbell, recover in a controlled way, and repeat the action again.