Document a4B7RNaO7ZpBQbNY9V2Yk3NjM

64 ROSS A. MC FARLAND be obtained with the aid of the metrical and statistical techniques of anthropome try, a branch of physical anthropology dealing with the measurement of man. It is suggested that the engineer consult with the anthropologist during the initial design stages rather-than at a later period when modifications may be costly. Although handbooks of biological data are of value as general reference and orientation material for the industrial specialist, the technical background and experience of the anthropologist are desirable for the most efficient gathering, interpretation, and application of the data. When the design engineer works in collaboration with the anthropologist he should be sure that the anthropologist (f) is adequately instructed as to the role of the man in the specific industrial operation; (2) knows the composition of the group of future operators in terms of age, sex, and any requirements used in personnel selection; (S) is aware of the body position(s) for operation of the equipment; and (4) is present to interpret and assist in the application of his data when the plans are being drawn.2 In some cases it may not be feasible or possible to design new machines "from the man out"; instead, the anthropologist may be forced to evaluate exist ing models. On such occasions the suggested procedure is as follows: he should, first, describe his population; second, ascertain the proportion of that population accommodated and the quality of that accommodation, with respect to comfort, .Bffinifino.y.,_healthr-amLsafetv: and, third, if not all operators are accommodated, establish size limits for selection and training. It seems obvious that a man should not be given intensive instruction only to find that he cannot fit the machine for which he has been trained; but such instances have occurred. In such a case the anthropologist must, fourth, then ascertain the nature and cause of any difficulties encountered and attempt to remedy them. His chief interest will inevitably be in specific installations within the working area, since these are usually responsible for many operational difficulties. After these first four steps have been taken, the experience gained in such evaluations should be used to set up criteria for new designs.11 ,,A^TTmiJA-BBLICATIQN_QF ANTHROPOMETRIC DATA ____ :________ , -'jriei^tEfffdKltional Anthropometric Measurements ....... Anthropometns'measurements were originally devised to facilitate the study of evolution -and-race^an^hence-some of the available .data..ar.emfJittl.e..use_t.Q .the . design engineer. In general, however, many of the traditional anthropometric dimensions are of some utility in problems of space design. For the most part they consist of body lengths, breadths, depths, and circumferences as illustrated "R. A. McFarland, A. Damon, H. W. Stoudt, A. L. Moseley, J. W. Dunlap, and W. A. Hall, Human Body Size and Capabilities in the Design and Operation of Vehicular Equipment. Harvard School of Public Health, Boston, 1953, IPWr riw!** .A HUMAN ENGINEERING AND INDUSTRIAL SAFETY 65 'wj'm figure. 1. These static dimensions, as they may be called, are useful in determin^TinTclearances and allowances in the working area. Examples would be the mini- r-, * 111 a hair as based on seat breadth, or minimum head clearance as g,` ,uAS,ed on sitting height or stature. In some cases new static measurements must he devised to fit special situations that arise only in space-design problems, such :the, distance from the floor to the under side of thigh (popliteal height), when ^,'r1 ated, in order to assure a comfortable seat height. For uniformity and accuracy spl^Sthropometric measurements should be taken either by anthropologists or y^J|%0Se adecluately trained in the techniques of anthropometry. Past experience whaniotinnm that human body dimensions taken during the course of routine mili- .iv physical examinations, for example, can rarely be accepted at face value M1 - i*' 7l J'.JF W ;V k- wAW 22 --jl6 -- Jjljgij-Tfcfire 1- Body measurements applicable to various kinds of equipment design. The dimensions may be identified by number. See Table 1 for the means and standard llffir1?*!8 f the8e measurements for selected groupB. (After Randall et al") ril /Xt1p'uld be remembered that many industrial occupational groups are highly MM^iffering from other groups and from the general public, as ,jvell. There$&[p^!^?P0PulBtion that will use a given machine should be measured directly, if i&^|}:l!=Possjbl-to do-so.-This is good practice, especially whereTimitatibns of space have been imposed upon the designer. An example of using p^lPtraMe groups would be the application of measurements' taken on men equipment to be used by a mixed population. Other diffig^is'i-will arise when an equipment dimension satisfactory for one condition ||^fe7?ith the requirements for a different condition. For example, Hoojjpn series of 3,867 people, using approximately equal numbers of(.both sexes, Ml ' L: m