Assessing Increased Activities of the Forearm Muscles Due to Anti-Vibration Gloves: Construct Validity of a Refined Methodology

Abstract

The primary aim was to test the construct validity of a surface electromyography (EMG) measurement protocol, indirectly assessing the effects of anti-vibration (AV) gloves on activities of the forearm muscles. AV gloves impose a relatively higher grip demand and thus a higher risk for musculoskeletal disorders. Consequently, activities of the forearm muscles should be considered when assessing AV glove performance. Effects of AV gloves on activities of the forearm muscles (ECR: extensor carpi radialis longus; ED: extensor digitorum; FCR: flexor carpi radialis; FDS: flexor digitorum superficialis) were measured via EMG, while gripping a handle with two grip force levels. Fifteen subjects participated with 11 glove conditions, including one with bare hand. Activities of ECR, FCR, mean of ECR and FCR (ECR_FCR), and mean of all four muscles were sensitive to wearing gloves. Compared with bare hand, combined ECR_FCR activities increased by 22%-78% (mean = 48%, SD = 28%) with gloves. The correlation coefficient (r) of ECR_FCR activities with glove thickness and manual dexterity scores were 0.74 (p < .05) and 0.90 (p < .001), respectively. A refined EMG methodology was the most sensitive to AV gloves with specific forearm muscles (ECR and FCR) and the 50-N handgrip force. Its construct validity was further substantiated by correlations with glove thickness and manual dexterity. Assessment of the effect of AV gloves on activities of the forearm muscles can yield design guidance for AV gloves to reduce grip exertion by the gloved hand.