Exercise your thin back in the gym.
The pressure on muscles is limited! So do your best! Don't demand too much intensity and intensity of exercise! It will be better to increase the amount of exercise slowly! Also, if you want to be effective, you'd better eat scientifically, otherwise the exercise will be discounted! In fact, you feel sore in the forearm area because your back nerves and muscles are connected with the muscles of the forearm! A slight acid swelling is no problem!