Effects of arm suspension in simulated assembly line work: muscular activity and posture angles.
The electromyogram and posture angles of the shoulder and arm were recorded during sitting manipulative work in three positions, with and without the forearm suspended by a balancer. A Selspot system was used to record movements. The results from 12 female subjects (mean age 29 yr) showed that the activity in deltoideus anterior decreased significantly by using a balancer. Lower mean values were also noted for deltoideus lateralis and the trapezius muscles. The neck inclination increased with higher work area position, but was independent of the use of a balancer.
D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D004576:Electromyography; D006804:Ergonomics; D005260:Female; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D019547:Neck Pain / Q000503:physiopathology / Q000517:prevention & control*; D011187:Posture / Q000502:physiology*; D012782:Shoulder