Muscle activation assessmentandergonomics risk amonglifted operation workers in the industry

Abstract

          Majority of workers in industry who have behavior that lead to musculoskeletal disorders, particularly in forceful
movements, lifting task with convey machinesand inappropriate ergonomics postures can cause of injury at the back.The
purpose of study to assess the muscle activation and ergonomics risk. This cross-sectional descriptive study was conducted in
12 industrial workers who responsible for continuously handling at least 1 hour per day by working with the conveymachine,
and data were collected with an interview questionnaire and measured muscle activation by electromyography (EMG) for
musclefatigue and maximum voluntary contraction (%MVC), and the use of the Rapid Entire Body Assessment (REBA) and NIOSH
lifting. The resultsfrommuscles fatigue were divided into 2 groups, fatigue and non-fatigue group, and identified bythe mean
MF/timeslope of electromyogram founded -11.2 and 2.18, respectively. The results of %MVC showed that average %MVC of workers who fatigue and non-fatigue was 48 and 54.25 respectively. And theresults from MSDs self-assessment by workers found 25.00% of them had complaint of back area at low and high level. The ergonomics risks from REBA were mostly found to be high risk level while lifting and medium risk level while lowering in 2 groups. NIOSH results indicated that 2 groupswere exposed to very high risk while lifting and low level while lowering.These findings identified thathad ergonomics risk in industrial workers who responsible for continuously handling at least 1 hour per day by working with machines from muscle fatigue. It is suggested that should promote workers to avoid inappropriate posture especially, raise the arms high above the head, more trunk flexion and trunk rotationthat may affect to be musculoskeletal disorders in acute and chronic phaseby operating levels of conveyer to fit to individual anthropometry.