In order to conduct a study on the importance of the wrist joint, which causes a lot of pain among middle-aged people, in relation to work related to musculoskeletal disorders, the effect of stretching on grasping power was studied. In order to compare the grasping power of the wrist for middle-aged people in their 50s, the experiment was conducted by comparing before and after the wrist joint motion stretching. According to the experimental results of wrist gripping power for the control group and the experiment group on wrist gripping power, it was investigated that stretching did not change much in increasing wrist gripping power, but stretching application had an effect on wrist gripping power. In terms of preventing musculoskeletal accidents, reducing pain due to degenerative diseases, and preventing accidents, stretching seems to have an effect when approaching, so it is considered that continuous stretching before and after work is necessary. Therefore, it is suggested that stretching time secured quantitatively through safety and health education before work is necessary.

It is necessary to make preventive method for the trauma and disturbance complications of orofacial area because athletic trauma are physical and mental defects. Since 1913, an italian boxer discussed mouth guard with dentist and used it. It was reported that mouth guard from field prevented trauma, increased the muscle force and activated electromyogram although the history of mouth guard wearing was short. The mouth guard has prevented the trauma and also increased the muscle force. The purpose was to study muscle force and activity of EMG with mouth guard wearing. It concluded that mouth could prevent trauma and increase the muscle force