![]()
Section IV
Standards for Manual Material Handling Tasks
![]()
17 | Repetitive Actions and Movements of the Upper Limbs Enrico Occhipinti and Daniela Colombini |
CONTENTS
Introduction
Scope of the Standards
EN 1005-5: Risk Assessment for Repetitive Handling at High Frequency
ISO 11228-3: Handling of Low Loads at High Frequency
Main Definitions
Work Task
Repetitive Task
Work Cycle
Cycle Time
Technical Action (Mechanical)
Repetitiveness
Frequency
Force
Posture and Movements
Recovery Time
Additional Risk Factors
Contents of the Standards
General Recommendations
Risk Assessment
En 1005-5
Hazard Identification
Risk Estimation by Simple Methods (Method 1)
Risk Evaluation by Detailed Method (Method 2)
Annexes
Iso 11228-3
Hazard Identification
Simple Risk Assessment
Risk Evaluation by Detailed Method
Risk Reduction
Annexes
References
Full Name of the Standards
EN 1005-5: Safety of machineryāHuman physical performanceāPart 5: Risk assessment for repetitive handling at high frequency.
ISO 11228-3: Manual handling Part 3: Handling of low loads at high frequency.
Introduction
Working tasks that require manual repetitive actions at high frequency may cause the risk of fatigue, discomfort, and musculoskeletal disorders. A proper risk assessment and management should seek to minimize these health effects by considering a variety of risk factors related to the duration of exposure, the frequency of actions, the use of force, the postures and movements of the body segments, the lack of recovery periods, and other additional factors (Colombini et al., 2001).
To this regard, two parallel standards have been produced in 2007, respectively, by CEN and ISO:
Though the two mentioned drafts are devoted to different targets, they are conceptually similar and can be presented in the same context.
Scope of the Standards
EN 1005-5: Risk Assessment for Repetitive Handling at High Frequency
This European standard presents guidance to the designer of machinery or its component parts in controlling health risks due to machine-related repetitive handling at high frequency.
The standard has been prepared to be a harmonized standard as defined by the U.E. āMachinery Directiveā and associated EFTA regulations but, for procedural reasons, has been published to only be an informative voluntary standard.
It applies mainly to designers and producers of new machinery and assembly lines for professional use operated by the healthy adult working population.
The machinery designer has to specify reference data for the action frequency of the upper limbs during machinery operation. The standard presents a risk assessment method and gives guidance to the designer on how to reduce health risks for the operator.
ISO 11228-3: Handling of Low Loads at High Frequency
This International Standard establishes ergonomic recommendations for repetitive work tasks involving the handling of low loads at high frequency (by upper limbs).
The standard provides information for all those involved in the design (or redesign) and risk assessment of manual repetitive tasks and jobs.
It is designed to provide guidance on several task variables, evaluating the health risks for the working population. It applies to the adult working population; the recommendations will give reasonable protection for nearly all healthy adults.
Main Definitions
Work Task
An activity or activities required to achieve an intended outcome of the work system (e.g., stitching of cloth, the loading or unloading of pallets).
Repetitive Task
Task characterized by repeated cycles.
Work Cycle
A sequence of (technical) actions that are always repeated the same way.
Cycle Time
The time elapsedāfrom the moment one operator begins a work cycle to the moment that the same work cycle is repeated (in seconds).
Technical Action (Mechanical)
Elementary manual actions required to complete the operations within the work cycle, such as holding, turning, pushing, cutting.
Repetitiveness
Quality of task when a person is continuously repeating the same cycle, technical actions, and movements in a significant part of a normal workday.
Frequency
The number of technical actions per minute.
Force
The physical effort required of the operator to execute the task.
Posture and Movements
The positions and movements of the body segment(s) or joint(s) required to execute the task.
Recovery Time
The period of rest following a period of activity that allows restoration...
