title: A hand speed-duty cycle equation for estimating the ACGIH hand activity level rating.
abstract: An equation was developed for estimating hand activity level (HAL) directly from tracked root mean square (RMS) hand speed (S) and duty cycle (D). Table lookup, equation or marker-less video tracking can estimate HAL from motion/exertion frequency (F) and D. Since automatically estimating F is sometimes complex, HAL may be more readily assessed using S. Hands from 33 videos originally used for the HAL rating were tracked to estimate S, scaled relative to hand breadth (HB), and single-frame analysis was used to measure D. Since HBs were unknown, a Monte Carlo method was employed for iteratively estimating the regression coefficients from US Army anthropometry survey data. The equation: HAL = 10[e(-15:87+0:02D+2:25 ln S)/(1+e(-15:87+0:02D+2:25 ln S)], R(2) = 0.97, had a residual range ± 0.5 HAL. The S equation superiorly fits the Latko et al. ( 1997 ) data and predicted independently observed HAL values (Harris 2011) better (MSE = 0.16) than the F equation (MSE = 1.28).
authors.affiliation: a Department of Industrial and Systems Engineering , University of Wisconsin-Madison , Madison , WI , USA.
authors.forename: Oguz
authors.initials: O
authors.lastname: Akkas
authors.forename: David P
authors.initials: DP
authors.lastname: Azari
authors.forename: Chia-Hsiung Eric
authors.initials: CH
authors.lastname: Chen
authors.forename: Yu Hen
authors.initials: YH
authors.lastname: Hu
authors.forename: Sheryl S
authors.initials: SS
authors.lastname: Ulin
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Armstrong
authors.forename: David
authors.initials: D
authors.lastname: Rempel
authors.forename: Robert G
authors.initials: RG
authors.lastname: Radwin
mesh_terms: D000886:Anthropometry / Q000379:methods; D001696:Biomechanical Phenomena; D006225:Hand / Q000502:physiology*; D006801:Humans; D008889:Military Personnel; D009068:Movement; D016272:Occupational Health; D005082:Physical Exertion; D012044:Regression Analysis; D013647:Task Performance and Analysis; D020711:Threshold Limit Values; D014481:United States; D014937:Work / Q000502:physiology*
keywords: exposure assessment; repetitive motion; work-related musculoskeletal disorders