Operating forces on agricultural machinery Analysis and measurement of manual operating forces International Conference “Women’s health and work” Katharina von Rymon Lipinski (KAN) and André Klußmann (ASER) Brussels,

Who is KAN? International Conference "Women's health and work"2 KAN is the Commission for Occupational Health and Safety and Standardization (in Germany) KAN itself is not a standardization body, however!

International Conference "Women's health and work"3 Presenting: KAN Tasks monitor standardization work from the OSH perspective and to ensure OSH interests are reflected in standardization. “pools” the opinions of OSH stakeholders (based on a broad consensus between all parties) and supplies the resulting position as input, in the form of comments, on current and planned standardization projects or existing standards Not enough knowledge? KAN study

How we can support you We formulate consensus-based OSH-positions on key standardization issues We asses standards to determine if they meet OSH requirements (from the German point of view) We exert influence on standardization programmes and mandates We initiate new standards if necessary from the OSH point of view We distribute information on standardization work for OSH experts International Conference "Women's health and work"4

International Conference "Women's health and work"5 Why a KAN study on actuating forces? KAN study on agricultural machinery 2008: standards were checked if they fullfil the essential health and safety requirements of the Machinery Directive National process of revision of standards But: one problem left How to deal with actuating forces on agricultural machinery? And how to verify data given in standards on a certain machine?

Operating forces on agricultural machinery Analysis and measurement of manual operating forces Background In the standards for agricultural machinery, two basic statements often made according to operating forces: During actuation of controls (e.g. levers) or moving of components of machines (e.g. large flaps), an average value of 250 N (200 N) and a maximum value of 400 N (250 N) must not be exceeded! International Conference "Women's health and work"6 Are the values suitable? How to measure the force?

Examples of operation forces International Conference "Women's health and work"7

Location of operating elements … International Conference "Women's health and work"8 DIN 33402, part 2 e.g. females, 5. Percentile upwards: 1840 mm forwards: 625 mm

Operating forces on agricultural machinery Analysis and measurement of manual operating forces Aims To develop a well practicable measuring procedure for the determination of operating forces at machines. To check whether maximum acceptable operating forces (400 N peak and 250 N mean force) often mentioned in ISO standards for mobile agricultural machinery are arguable from an ergonomic point of view International Conference "Women's health and work"9 Gender aspect: Not (only) men‘s work! Today, more than ¼ of trainees in agricultural occupations in Germany are females (

Operating forces on agricultural machinery Analysis and measurement of manual operating forces Methods Development and testing of a manual procedure and an automatic procedure for the determination of operating forces Reference values: Measurement of maximum isometric body strength in typical postures during operating machinery International Conference "Women's health and work"10

Manual measurement procedure Measurement with hand held force gauge Movement by examiners Operating force to be angle of 90°determined is perpendicular to the manually operated part (permanent) Every test was repeated several times Tests at machines in field and at test stand in laboratory International Conference "Women's health and work"11

Example of manual measurement of operating force International Conference "Women's health and work"12

Automatic measurement procedure Measurement with computer-aided measuring system Movement by Winch Continuous angle measurement Every test was repeated 5 times Tests at machines in field and at test stand in laboratory International Conference "Women's health and work"13

Example of automatic measurement of operating force International Conference "Women's health and work"14

Comparison of the two measurement results Several tests have been done in the field at machines and in laboratory to compare the two methods Repeatability- and reproducibility-coefficient of variance (C.O.V.) over all measurements of operational force have been estimated  manual procedure has a higher variance but the variance is not essentially higher compared to the automatic procedure International Conference "Women's health and work"15 procedure Average repeatability C.O.V. Average reproducibility C.O.V. automatic 2,8 %2,9 % manual 4,4 %6,6 %

Discussion of measurement results The automatic procedure predominates in reproducibility The manual procedure is easier to apply, still provides adequate, slightly higher results The manual procedure requires practiced examiners International Conference "Women's health and work"16 Recommendations: 1)The manual procedure is sufficient to estimate the operating force 2)Only the measurement of the maximum force is repeatable, the mean force is strongly dependent on the speed of movement

Exemplarily determined maximum force values Measurements were done in standardized way in laboratory 8 subjects (4 females, 4 males) 3 cases (operating a lever, opening/closing side flaps and locking a ladder) in positions distributed over the human handling area 3,192 measurements with 133 combinations (direction / position) Results: 12 tables were generated in which orientation values of isometric maximum forces for different body positions are shown International Conference "Women's health and work"17

Tables International Conference "Women's health and work"18 Example table for maximum force of males (M) and females (W) in different spatial positions Kind of force exercise here: "Press the lever“

Summary / Discussion / Conclusions Measurement / methods Both procedures tested (manual and automatic) have advantages and disadvantages.  Tendency rather to manual hand-held force gauge Maximum allowable levels for operating force Previous values (250 N average, 400 N peak force) not recommended Significant differences between women and men have to be taken into account Significant differences in dependence of the spatial position have to be taken into account  User population must be specified International Conference "Women's health and work"19

Summary / Discussion / Conclusions Spatial position of controls / access Location of control must be in reach of potential users Recommendation: Consideration of 5th percentile females according to reach area (e.g. DIN ). Use of the report Method and reference values should be tested by machine designers and construction engineers for applicability If useful, a larger database is necessary for reference values International Conference "Women's health and work"20

More details … International Conference "Women's health and work"21

Contact Katharina von Rymon Lipinski Commission for Occupational Health and Safety and Standardization (KAN) - Secretariat Tel.: Dr. André Klußmann Institute of Occupational Health, Safety and Ergonomics (ASER) Tel.:

Picture credits Slide „Contact“: © Trueffelpix - Fotolia.com „Presenting: KAN“: © Vasilius - Fotolia.com „Why a KAN study…?“: © mr.nico – Fotolia.com „Who is KAN?“: © KAN „How we can support you?“: © KAN International Conference "Women's health and work"23