경부 자세에 따른 경부 근육의 피로도

Fatigue of the cervical muscles by prolonged cervical position

Purpose: This study is to identify the muscle fatigue and pain by various cervical positions in the VDT work. Methods: Twenty two volunteers (11 males and 11 females) participated in this study. Each subject gazes monitor in front of them for thirty minutes in the three cervical positions (neutral, 30 degree flexed, and 30 degree extended positions). Visual analogue scale (VAS) for the pain and pressure pain threshold(PPT) of the trapezius and levator scapula for the muscle fatigue were measured every fifteen minutes. Results: VASs after 15 minutes were $1.23{\pm}0.43$ in neutral, $3.0{\pm}0.93$ in flexed, and $5.27{\pm}1.03$ in extended position respectively and increased to $1.5{\pm}0.67$, $4.59{\pm}1.26$, and $7.73{\pm}0.98$ after 30 minutes. The order of magnitude of VAS was extended, flexed, and neutral position(p<0.01). PPTs in both sides of upper trapezius and levator scapula muscles were decreased at the three positions after 15 and 30 minutes respectively(p<0.01). There were no statistical differences of PPTs in neutral and flexed positions after 15 and 30 minutes(p<0.01). Extended position showed lowest PPTs in both side of upper trapezius and levator scapula muscles after 15 and 30 minutes(p<0.01). There were statistical differences of PPTs in extended position and the other two positions after 15 and 30 minutes(p<0.01). Conclusion: The cervical position that has the most influence on the cervical muscle fatigue and pain in the VDT work is extended position.