Anthropometry and Range of Motion

Transcription

1 Anthropometry and Range of Motion

2 Anthropometry Definition Anthropometry Introduction The study of the dimensions and certain other physical characteristics of the human body It is derived from the Greek words anthropos (man) and metron (measure). Critical element in workplace design - Accommodate users Large volumes of data available - Different sexes, ages, and geographical regions Freivalds A., (2009). Niebel s Methods, Standards, and Work Design. McGraw-Hill

3 TYPES OF ANTHROPOMETRIC DATA 1. Structural Anthropometric Data 2. Functional Anthropometric Data

4 1.STRUCTURAL ANTHROPOMETRIC DATA Structural anthropometric data are measurements of the bodily dimensions of subjects in fixed (static) positions. EXAMPLES To specify furniture dimensions. To determine ranges of clothing sizes.

5 2.FUNCTIONAL ANTHROPOMETRIC DATA Functional anthropometric data are taken under conditions in which the body is engaged in some physical activities. EXAMPLES Design of crane cabs Design of vehicle interiors

6 USES OF ANTHROPOMETRIC DATA To fit the task to the person. To avoid physical mismatches between dimensions of equipment and products and the corresponding user. To design for variability in people and not for the average.

7 Variation in body dimensions Anthropometry Introduction Enormous variation in body size among individuals Challenges - Designing workstations and equipment Who do we design for? - Average person - Extreme body sizes, i.e. largest or smallest Careful considerations required for design cut off points Depends on the design purpose Kroemer, K.H.E.., Grandjean, E. (1997) Fitting the Task to the Human. Taylor & Francis

8 Anthropometry Introduction Factors affecting body dimensions Human Variation - Age - Gender - Ethic Origin - Long-term population Shifts Clothing and Personal Equipment Kroemer, K.H.E.., Grandjean, E. (1997) Fitting the Task to the Human. Taylor & Francis

9 Anthropometry Introduction Body dimensions is based on no clothes. Clothing will add to physical dimensions Footwear and gloves can affect anthropometric dimensions - Allowances should be made to compensate Pheasant, S., Haslegrave, C., (2006). Bodyspace: Anthropometry, Ergonomics, and the Design of Work. Taylor and Francis Group.

10 1.BODY DIMENSIONS Minimum dimensions A door handle must not be lower than the highest standing knuckle height in a population so that all users can open the door without stooping.

11 MINIMUM DIMENSIONS CONT.. The width of a chair must be no narrower than the hip breadth of a large woman.

12 MINIMUM DIMENSIONS CONT.. The height of a doorway must be no lower than the stature of a tall man (plus an allowance for clothing and shoes).

13 MAXIMUM DIMENSIONS A door lock must be no higher than the maximum vertical reach of a small person.

14 MAXIMUM DIMENSIONS CONT Seat heights and depths must not exceed the maximum height and buttock knee lengths of small users.

15 Anthropometry Statistical Basis for Anthropometry Statistical procedure for anthropometric data Yield a wealth of information Assist in calculating percentiles and ranges of homogenous or composite groups Anthropometric dimensions are normally distributed - May be described by the mean and standard deviation - Accommodate users Large volumes of data available - Different sexes, ages, and geographical regions Freivalds A., (2009). Niebel s Methods, Standards, and Work Design. McGraw-Hill

16 Anthropometry Statistical Basis for Anthropometry Kth percentile Definition A value such that k percent of the data values are at or below this value and 100 k percent of the data values are at or above this value Percentiles provide a basis for estimating the proportion of a population accommodated by a design Normal transformation Z = X µ σ z = standard normal value corresponding to population cumulative density X = value of measured dimension µ = average, or mean of dimension for population SD = standard deviation of population Freivalds A., (2009). Niebel s Methods, Standards, and Work Design. McGraw-Hill

17 Anthropometry Standard standing posture subject stands erect looking straight ahead, arms to their side Standard standing posture erect on a horizontal flat surface and looking straight ahead Kroemer, K.H.E.., Grandjean, E. (1997) Fitting the Task to the Human. Taylor & Francis

18 Anthropometry Selected Anthropometric Measurements for US Adults (All dimensions in mm, except body weight given in kg) Dimension Male Percentiles Female Percentiles 5th 50th 95th St. Dev. 5th 50th 95th St. Dev. 1. Standing height Sitting height Knuckle height Knee height Popliteal height Elbow-rest height Thigh-clearance height Buttock-knee length Buttock-popliteal length Hip breadth Shoulder breadth (bideltoid) Weight, kg Source: Bodyspace by Stephan Pheasant. by Taylor and Francis

19 Anthropometry 1. Design for the individual Best design BUT very expensive Design dimensions to fit a specific individual Example: Design of a space suit 2. Design for an adjustable range From 5th percentile (small female) to 95th percentile (large male) Adjust to fit a wider range of people Best BUT expensive Example: Design of industrial chairs 3. Design for extremes For the small female (5 th percentile) OR the large male (95 th percentile) Examples: Design of the door post - for the large male Design of a shelf - for the small female 4. Design for the average Not recommended Design for 50 th percentile Only when used for a short duration Example: Design counter at the supermarket or a public place Freivalds A., (2009). Niebel s Methods, Standards, and Work Design. McGraw-Hill

20 Range of Variability of Voluntary and Passive Movements of Body Members (in degrees) Voluntary Passive Body Member and Movement Lower Limit Upper Limit Mean SD Lower Limit Upper Limit Mean SD Head Rotation (right) Arm at Shoulder Flexion (forward) Extension Abduction(side) Forearm at elbow Flexion (bend) Pronation (turn in) Supination (turn out) Hand at wrist Flexion Extension Abduction Adduction

21 Range of Variability of Voluntary and Passive Movements of Body Members (in degrees) Voluntary Passive Body Member and Movement Lower Limit Upper Limit Mean SD Lower Limit Upper Limit Mean SD Thigh at hip joint Flexion (forward) Extension Abduction (side) Internal Rotation External Rotation Leg at knee joint Flexion (bending) Foot at ankle Planter Flexion (bend up) Dorsal Flexion

22 Range of Motion Movement Ulnar Deviation (Transverse plane) Goniometer Wrist Flexion (Sagittal plane)

23 Range of Motion Factors Affecting Range of Motion Age Gender Race Body build Exercise Occupation Fatigue Disease Motivation Right vs. left side of body Zero gravity Clothing and personal equipment

24 Range of Motion Factors Affecting Muscle Strength Biological factors - Age - Gender - Race - Body build - Body position - Handedness - Fatigue - Exercise - Health - Diet - Drugs - Diurnal variations Environmental factors - Altitude - Acceleration Psychological factors - Motivation - Emotional state Occupational factors - Occupation - Clothing and personal equipment - Workplace equipment

25 Guidelines for Conversion of Standard Measuring Postures to Functional Stances and Motions To consider Slumped standing or sitting Relaxed trunk Wearing shoes Wearing light clothing Wearing heavy clothing Extended reaches Use of hand tools Comfortable seat height Do this Deduct 5 10% from appropriate height measurements Add 5 10 % to trunk circumference Add approximately 25 mm to standing and sitting heights; more for high heels Add about 5% to appropriate dimensions Add 15% or more to appropriate dimensions (Note: Mobility may be strongly reduced be heavy clothing) Add 10% or more for strong motions of the trunk Center of handle is at about 40% of hand length, measured Add or subtract up to 10% to or from standard seat height Kroemer, K.H.E.., (2008) Fitting the Task to the Human, 6 th Ed. Taylor & Francis.

26 ADVANTAGES OF ANTHROPOMETRIC DATA Increase accuracy Reduce Fatigue Better comfort Reduce chance of injuries Time management

27 CONCLUSION Anthropometry plays a major role in increasing productivity of the organization. Based on the populationwe have to design the workspace and equipment's. According to the level of comfort ability the quality of the product will get raise.

28 REFERENCE Bridger R.S(2008).Introduction To Ergonomics, 3 rd Edition. ropometry/chapter1/ch1-7.htm