1. Chapter 3.3 The Body and Performance Human Performance Engineering Robert W. Bailey, Ph.D. Third Edition

2. 2 Reasons to Consider Body Dimensions: 1. Certain body dimensions seem to be related to optimal performance in some activities. 2. User must fit into space provided, be able to make required reaches or movements.

3. Limits: Pygmy people of central Africa- Avg. 4’ 7” Nilotes of the Sudan – Avg. 5’8 ½” Tallest – Robert Wadlow- 8’11” Shortest – Pauline Musters – 1’11” 2’-9’ =Extreme Outer Limits

4. Who should we design for? What % of the people?

5. Anthropometry- Studies of body dimensions Designing for Average Person is a mistake Design for 95% of potential users

6. 2 Kinds of Measurement: Static Functional

7. Original Population

10. Table 5-1 Body Dimension for Office Workers in Inches (CM) (To be used with figure 5-6) Estimated percentiles LegendDimensions 2.5 th 5 th 50 th 95 th 97.5 th A-1Vertical reach 73.5 (187) 75.0 (190) 80.5 (204) 86.0 (219) 87.5 (222) A-2Stature61.5 (156) 62.0 (158) 66.5 (168) 70.5 (179) 71.5 (181) A-3Eye height, standing56.5 (144) 57.5 (146) 62.0 (157) 66.0 (167) 67.0 (169) A-4Head Circumference21.5 (54) 22.0 (55) 22.5 (57) 23.0 (58) 23.5 (60) B-1Thumb tip reach27.5 (69) 28.0 (71) 31.0 (78) 33.5 (86) 34.5 (87) B-2 Shoulder height50.0 (128) 51.0 (130) 55.0 (139) 59.0 (149) 59.5 (151) B-3Elbow to floor 39.5 (100) 40.0 (101) 42.5 (108) 45.0 (115) 45.5 (116) B-4Foot length 9.0 (23) 9.5 (24) 10.0 (25) 10.5 (27) 11.0 (28) B-5Foot width 3.0 (8) 3.0 (8) 3.5 (9) 4.0 (10) 4.0 (10) C-1Head to seat height 32.5 (83) 33.0 (84) 35.5 (90) 37.5 (96) 38.0 (97) C-2Eye Height, sitting 28.0 (71) 28.5 (72) 30.5 (78) 32.5 (83) 33.0 (84) C-3Shoulder breadth 16.0 (40) 16.0 (41) 18.0 (46) 19.5 (50) 20 (51) C-4Hip breadth 13.0 (33) 13.5 (34) 15.0 (38) 17.0 (42) 17.0 (43) D-1Hand length 6.5 (17) 6.5 (17) 7.5 (19) 8.0 (21) 8.0 (21) D-2Hand width 3.0 (7) 3.0 (7) 3.5 (8) 3.5 (9) 4.0 (9) E-1Knee height 19.0 (48) 19.0 (49) 21.0 (53) 23.0 (58) 23.0 (59) E-2Popliteal height 15.0 (38) 15.0 (39) 17.0 (42) 18.0 (46) 18.5 (47) E-3Buttock to popliteal 17.5 (45) 18.0 (45) 19.5 (49) 21.0 (54) 21.5 (55) E-4Buttock to knee 21.5 (55) 22.0 (56) 23.5 (60) 25.0 (64) 25.5 (65) E-5Elbow to wrist 9.0 (23) 9.0 (23) 10.5 (26) 11.5 (29) 12.0 (30) E-6Thigh clearance 5.0 (12) 5.0 (13) 6.0 (15) 6.5 (17) 7.0 (18) E-7Shoulder to elbow 12.5 (31) 12.5 (32) 14.0 (35) 15.0 (38) 15.0 (39) E-8Elbow rest height 8.0 (19) 8.0 (20) 9.5 (24) 11.0 (28) 11.5 (29) E-9Shoulder to seat height 22.0 (56) 22.5 (57) 24.5 (62) 26.5 (67) 27.0 (68)

11. Table 5.2 Useful Body Dimensions for Reach (Accommodating 95% of Users) Dimension 5 th Percentile Example of use Vertical reach (A-1) 75in. Placement of highest book 190cm shelf Eye Height (A-3) 57.5in. Allowing most workers to look 146cm over the side of their cubicles Thumb tip reach (B-1) 28.0in. Maximum distance for placing 71cm CRT controls

12. Three Purposes of Measurement 1.To help in making decisions concerning reach 2.To help in making decisions concerning clearance 3. Where ranges of dimensions are important

13. Range of Movement Movable joints: Hinged joints- fingers Pivot joints-elbow Ball and socket joints –shoulder and hip

14. Healthy people – 20-60=Good mobility Arthritis – Common after 45 Women exceed men in all joints but the knee Slender people exceed heavier people

15. Strength Maximum strength – Late 20’s Age 40 – 90% Age 50 – 85% Age 60 – 80%

16. Resistance levels for controls should not require the application of maximum strength Low enough - Prevent fatigue & discomfort High enough – Prevent inadvertent operation of controls