Relative optimum grip span as a function of hand anthropometry
International Journal of Industrial Ergonomics, cilt.34, sa.1, ss.1-12, 2004 (Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 34 Sayı: 1
- Basım Tarihi: 2004
- Doi Numarası: 10.1016/j.ergon.2004.01.007
- Dergi Adı: International Journal of Industrial Ergonomics
- Derginin Tarandığı İndeksler: Scopus
- Sayfa Sayıları: ss.1-12
- Anahtar Kelimeler: Grip force, Handle design, Modified thumb crotch length (TCLm), Relative optimum grip span (ROGS), Span efficiency coefficient (η), Tool design
- Boğaziçi Üniversitesi Adresli: Hayır
Özet
This study investigates the optimum grip span relative to an individual's hand anthropometry (ROGS) for an isometric power grip exertion. Maximum voluntary isometric grip force (MVGF), muscular activity (EMG) and subjective rating (SR) were used as criteria. Two complementary experiments were conducted. In both experiments, nine different widths of span, separated with 0.5cm intervals, were tested across 12 subjects. The span size was a function of one's modified thumb crotch length (TCLm). In the first experiment, the grip spans were tested as a function of MVGF and SR. The results of this experiment indicate TCLm-2 as the ROGS. The SR was also supportive of this result. In the second experiment, EMG at a constant force (30% MVGF) was evaluated as a function of the grip span. The EMG based efficiency coefficients indicate TCLm-2.5 as the optimum span, resulting in the least muscular activity. Based on the analysis of MVGF, EMG and SR, the ROGS is in the interval, TCLm-2.5≤ROGS≤TCLm-2, indicating a precise location of optimum grip span as a function of one's TCLm. This result suggests that hand-powered tools with two-handles should be designed for adjustability as a function of TCLm. Relevance to industry Excessive grip force exertion is one of the most important factors contributing to the occurrence of upper extremity cumulative trauma disorders, in addition to reducing workers' productivity. This study suggests a new tool design criterion for minimizing unnecessary effort and increasing productivity. © 2004 Elsevier B.V. All rights reserved.