Preliminary study evaluating manual dexterity tests assessing gloves protecting against cuts and stabs by hand knives

Abstract

The paper presents preliminary results on the research methodology of evaluating the ergonomic properties of gloves protecting against cuts and stabs by hand knives. Four manual dexterity tests were selected for the study: TEST 1: evaluation of fine finger movements pursuant to PN-EN 420; TEST 2: cylinder grip and pull test according to PN-EN 1082 evaluating gross movements of the arms and hands; TEST 3: Purdue Pegboard Test evaluating fine finger movements; TEST 4: evaluation of gross movements of the arms and hands while performing simulated occupational tasks. The tested gloves differed in terms of construction and material (metal mesh or knitwear incorporating a metal yarn) and were selected depending on the scope of work activities performed during meat cutting and boning. The tests were conducted on a homogeneous group of subjects. During the performance of the four dexterity tests, we monitored the loading of four groups of muscles of the upper limb (adductor pollicis, extensor carpi radialis, flexor carpi ulnaris, and biceps brachii) using surface electromyography (EMG). Additionally, subjective sensations concerning the strain on the upper limb were evaluated using a questionnaire survey.The objective of the study was to identify a group of tests that would be characterized by high sensitivity and ensure reliable assessment of gloves protecting against cuts and stabs by hand knives. The results showed that not all of the dexterity captured differences in the way the gloves affected dexterity. This was corroborated by electromyographic measurements, which revealed considerable differences in load of upper limb muscles when using various gloves and further supported by the subjective sensations of the participants, as reported in the questionnaire study. It was concluded that in order to reliably evaluate the ergonomic properties of gloves protecting against cuts and stabs by hand knives it is necessary to design new dexterity tests that would reflect actual workplace conditions, and could simulate occupational activities. Workplace observations helped to identify specific aspects of manual dexterity (fine, medium, gross), and types of hand movement associated with professional activities including different force configurations (finger flexion, wrist abduction, and pressing with the fingers and wrist). Based on those observations three new manual dexterity tests dedicated exclusively to evaluation of the ergonomic properties of gloves protecting against cuts and stabs by hand knives have been proposed.