Forceful Exertions

Table of Contents

Expand all Collapse all

Information on this page is drawn from "Participative ergonomics in civil construction handbook" published by Queensland Government

Forceful Exertions

Forceful exertions place high loads on muscles, tendons, ligaments, joints and discs. Muscles fatigue with increased exertion and need more time to recover. If soft tissue does not have time to recover, injury is likely to develop over a period of time. If the exertions are forceful enough, body tissues may be damaged immediately.

Forceful exertions include forces exerted by muscles, such as when lifting items, carrying loads, holding one position for a period of time, or using a forceful grip. Exposure to forces also occurs as a result of external forces applied to the body, such as the weight of a load being carried, or when jumping down when getting out of mobile plant.

It should be noted that it is the amount of force relative to the capability of the tissue which is important. For example, the small tissues of the hand may be injured by relatively low forces.

Example of Injury Mechanisms

The following example illustrates how injury occurs when the load applied to the musculoskeletal tissues is greater than the capacity of the tissues to withstand the force.

In this diagram, an acute injury can occur if the load on the tissues rises dramatically during a single extreme exertion.

Factors Effecting Level of Muscular Effort

The level of muscular effort needed to do a job may be increased by factors such as:

awkward or fixed working postures
heavy, bulky, unstable or difficult to grip loads
fast, sudden or jerky movements
working with a grip that does not allow a large area of the hand to contact the load
using vibrating tools that need more effort to grip
wearing gloves
using poorly designed hand tools
the way loads are handled (e.g. physically lifting, pushing, pulling or carrying)
poorly maintained tools and equipment.

Often it is a number of factors that will increase the risk of injury from forceful exertions.