Arm lengths and arm reaches: Some interrelationships of structural and functional body dimensions

Abstract

Structural measurements of the human body have for the most part been of little practical use as indicators of such functional body dimensions as arm reaches. These dimensions, which define the area around the body to which a person can reach given certain specified conditions and constraints are often critical for the design and layout of workspaces. However, they are relatively difficult and time‐consuming to obtain, usually requiring specially constructed measuring systems for each differing design situation, as well as resurveys for each physically distinct population. An alternate approach, described here, investigates the interrelationships between these two classes of measurements with the aim of predicting functional reaches from structural body dimensions. In the present study traditional structural measurements and 117 functional arm reaches were obtained on 100 subjects. Correlations between the two types of measures are reported. Regression equations are presented which can predict functional arm reaches from two structural body dimensions on anthropometrically differing populations under a fixed set of workspace conditions.

Reach Capability of Men and Women: A Three-Dimensional Analysis

“…Either the reference systems, such as in Chaffee (1969), Faulkner andDay (1970), andStoudt (1973) are different from or unrelated to that used in the current study, or the geometry of the seat was different, such as in the studies referred to above and in Bullock and Steinberg (1973) and Bullock (1974). In Haslegrave (1970) and King, Morrow, and Vollmer (1947) as well as others, the manner of reach is different.…”

“…[Garrett, Alexander, and Matthews, 19701 Correlation coefficients were calculated for reach distances, 7 anthropometric dimensions, and age, weight, and Heel-point to H point distance. Stoudt (1973) presented correlations between these 10 dimensions and reaches at 00, 100, 20', 300, 400, and 500 and levels at 5, 9, 13, and 17 inches above H point. He provided prediction formulae (regression equations) for estimating reaches from the anthropometric dimensions elbow-fingertip length and shoulder-elbow length.…”

“…To obtain crossover reach information, subjects reached to L30° with their right hand and to R30° with their left. A valid reach was obtained when the subject reached with *This is apparently not the same as the H point used in Stoudt et al (1970), Stoudt (1973), and described in Society of Automotive Engineers (1970 his thumb and forefinger and retained the capability to turn the knob 900. All reach data were expressed as horizontal reach distances from a vertical line through SRP along the axes of the measuring rods.…”

“…The authors also investigated the effects of different levels of restraint on reach, including firmly adjusted lap belt and shoulder harness, firm lap belt and 4 inches of slack in the shoulder harness, and firm lap belt and inertia reel "wound out." Stoudt et al (1970) and Stoudt (1973) reported their investigations of reach capability and the interrelations between selected traditional static anthropometric measures and functional arm reaches. The aims were to provide useful reach data for automotive use and to predict functional reaches from two anthropometric dimensions.…”

“…The experimental situation was purposely designed to yield data applicable to aircraft cockpits. Stoudt's (1973) study of the interrelations between anthropometric dimensions and reach distances included 50 men and 50 women. The seat structure was typical of automobiles.…”