들기작업시 목 자세에 따른 근육의 활동에 관한 연구

Abstract

Despite the fact that most of the manufacturing sites, heavy industries, and construction sites are mechanized and automated, many jobs are being made by manpower. According to the Ministry of Employment and Labor 's analysis of the status of industrial accidents, the number of disaster victims of musculoskeletal diseases in 2017 is 5,195, of which 2,638 are musculoskeletal injuries related to back pain. Musculoskeletal injuries related to the lumbar spine are very high, accounting for about 50.8% of the total musculoskeletal disorders. According to the data of the Korea Occupational Safety and Health Agency, the major cause of lumbar disease is lifting/dropping, transportation/movement, etc. There are many studies on frequency of lifting, symmetry/asymmetry, and lower limb, but there is little research on the difference in load on the waist and neck muscle according to the angle of the neck. Therefore, this study aims to provide basic data for improvement of lifting work posture and prevention of musculoskeletal diseases by analyzing the degree of mobilization of splenius capitis, upper trapezius, middle trapezius, iliocostalis lumborum muscles according to the angle of neck in lifting work. Independent variables were set as 30° flexion, neutral, 30° extension of neck posture, maximum vountary contraction(MVC), 75% MVC, 50% MVC, 25% MVC and 0% MVC. The dependent variable was set as the EMG value for each strength. The experimental equipment used was a TeleMyo 2400T G2 for EMG measurement and a Digital Dynamometer to maintain each% MVC. The EMG was measured for 3 seconds in three posture and five load conditions with independent variables, and the rest interval was 10 minutes. Experimental results showed the maximum MVC at 30° extension. Muscle mobilization was continuously increased according to the level of the load.