Information on this page is drawn from "Participative ergonomics in civil construction handbook" published by Queensland Government
Repetition
Repetition means making the same type of movements over and over (e.g. laying bricks). The work cycle is the time taken to perform the task once without interruption (e.g. the time to lay one brick). Tasks involving short cycle times (less than 30 seconds) and performed for more than one hour, are considered to be a risk because the same muscles and other soft tissues are being used continuously. This contributes to their fatigue and risk of injury. Tasks involving longer cycle times and shorter task duration will have a lower risk of injury.
Examples of Repetitive Tasks with Short Cycle Times
Laying Paving Blocks
Shovelling Road Base
Duration
Duration is the time taken to perform the task once, or perform the task repeatedly without a break. The longer a task takes, the greater the cumulative load on the musculoskeletal tissues. If the same musculoskeletal tissues are loaded without a break for extended periods, then the mechanical properties of those tissues begin to change, decreasing their functional capacity and increasing the likelihood of injury. Duration may be considered as a significant risk factor when a task is performed continuously for one hour or longer.
Examples of Tasks Involving Long Durations
Screeding concrete
Laying reinforcing steel
