Biomechanical Analysis of Cashiers in Seated and Standing Postures

Abstract

A laboratory experiment was conducted to understand the effect of posture on the entire body during checkout work. This research provides a biomechanical and physiological evaluation of the cashier while working at a recommended checkstand in two different postures, sitting and standing, in order to provide recommendations for minimizing MSD risk potential for cashiers. Results showed higher muscle activity for the left and right deltoid, left and right levator scapulae, and left trapezius. A general trend followed such that sitting produced higher levels of muscle activity than standing for neck, shoulder, and back muscles. Static levels of muscle activity (p=0.1) were above recommended values of 2–5% MVC. Posture results showed that shoulder abduction was reduced when standing, although neck flexion increased. Recommendations for cashier workstations include centering the scanner relative to the cashier's mid-sagittal plane, while providing postural relief and the opportunity for the cashier to stand.