Date of Graduation


Document Type


Degree Name

Master of Science in Kinesiology (MS)

Degree Level



Health, Human Performance and Recreation


Kaitlin Gallagher

Committee Member

Michelle Gray

Second Committee Member

Tyrone Washington


Biomechanics, Ergonomics


The purpose of this study was to investigate the impact of UPC placement on upper-body kinematics and muscle activity associated with cashier work. Seventeen female participants who had worked at least 1000 hours as a cashier and did not meet any exclusion criteria were recruited. Multi-sided UPC items, which included extra and/or larger barcodes, were compared to items with a traditional UPC placement. Two mock carts of eighteen items were scanned for each UPC type. Electromyography was applied bilaterally to the biceps brachii, middle deltoid, flexor digitorum superficialis, and upper trapezius muscles. Cumulative and peak muscle activity were calculated for each trial. Motion capture was placed on the torso, upper arm, forearm, and hand segments and tracked using a Qualysis motion capture system. Range of motion (ROM) values for shoulder flexion/extension, abduction/adduction, and internal/external rotation were calculated. The time to scan each cart from initial movement to return to starting position was also measured. A main effect of UPC type on cumulative muscle activity was found for all muscles (biceps brachii p=.002, middle deltoid p=.003, flexor digitorum p=.001, upper trapezius p=.001), all were lower with multi-sided UPC. For peak muscle activity, there was an interaction between UPC type and side (p=.036), values on the left were lower with multi-sided UPC items. There was also an interaction between UPC type and side for flexion/extension ROM (p=.031), with multi-sided UPC items reducing ROM by an average of 6 degrees. Mock carts with traditional items took an average a 5 fewer seconds to complete. Future studies should investigate if the increased efficiency and lower cumulative muscle activity is beneficial over the course of an entire work shift.

Included in

Biomechanics Commons