Ergonomic Analysis of a Novel Shelf Stocking Cart

Abstract

This study investigated the potential for an ergonomic intervention, specifically a prototype height-adjustable stocking cart to reduce the physical demands experienced when stocking shelves. This study compared muscle activity, kinematics, and subjective preferences when participants used the prototype cart versus a traditional, manual stocking method. Nine males and three females participated in this study. A traditional stocking method was compared to the prototype cart method for two types of dry grocery products as they were moved to three different destination shelf heights. EMG data, kinematic data, and subjective feedback generally favored the cart prototype over the traditional method. Bilaterally, anterior deltoid muscle activity was reduced for the cart condition when transferring products to the lower and higher shelves; trapezius activity was reduced for only the higher shelf; right side erector spinae activity was reduced for the lower shelf. The cart primarily benefited the anterior deltoid and trapezius descendens through reduced shoulder flexion. There were interaction effects of cart and shelf height on shoulder and spine kinematics. Questionnaire data showed that participants favored using the prototype. Study results support the continued development of the prototype cart toward a commercially available ergonomic aid for shelf stockers.