A six-year-old child’s whole hand is sore when he writes, which may be caused by lack of calcium, hand muscle strain, and over exertion. 1. Calcium deficiency: lack of calcium in the body leads to insufficient cartilage nutrition in the body, the cartilage part of the body is easy to lack, triggering a variety of arthritic wear and tear pain, aches and pains. Due to the hand part of the joints and cartilage components of the hand, which can appear as soon as the writing of the whole hand on the phenomenon of acid. 2. Hand muscle strain: may be due to the child’s prolonged use of the hand to write, the hand does not get rest, thus causing the hand muscle strain, and then the child can appear to write the whole hand on the phenomenon of soreness. 3. Excessive force: the muscles were originally in a relaxed state, when writing, suddenly exerted too much force, resulting in rapid muscle tension, which can cause a write the whole hand on the phenomenon of soreness. It is recommended that a six-year-old child with a sore hand go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying the condition.