Construction opportunities, particularly in natural resources sectors, offer near limitless opportunities for trades’ people. Much of the work conducted in these fields requires work on a scaffold at various heights. Of course, falls from scaffolds are important issues for this field and represent a key focus of health and safety personnel. In a recent article by Min et al (2012), they review some objective and subjective measures of balance in expert and novice scaffold users. This week on the blog, we present the finding of this group and how these results might be important for the construction industry.
The authors recruited a group of 4 novice and 4 expert construction workers and had them perform simulated work on a scaffold under 4 conditions: low and high height, and with and without handrails at each height. They used foot pressure sensors to calculate shifts in posture/balance (Centre of pressure measurements in the anterior-posterior and medio-lateral direction) while the participants performed their work.
The findings were interesting. There were more shifts among the novice group, at the higher height and in situations where there were no handrails. The fact that novices had more shifts in posture indicates that novice workers have less stability, and therefore would be at a higher risk of falling and developing injury. Additionally, the increase in shifting would increase fatigue and potentially place strain on the lower back. The authors note that higher platforms are more sensitive to perturbations, which forces increased shifting by employees to counteract perturbations under their feet. With hand rails, it is likely that employees feel more at ease and become less concerned with constantly shifting their posture to prevent falls.
The authors noted that this research shows support for reinforcement of platforms to reduce perturbations, and ensuring well-constructed hand rails are in place. These are not new concepts, and are already strongly enforced in the field. However, the finding that newer employees are less stable when using a scaffold is particularly interesting. They recommended using biofeedback tools during training of new employees to show them that they are shifting their balance too much and becoming unstable. Exposure to scaffolds and these feedback mechanisms might ultimately improve stability training of new employees and reduce the risk of accidents and fatigue.
This article has some interesting insights. It demonstrates that biomechanical analysis and tools can be important in training employees for work on scaffolds. These results might also help to explain the increased incidence of falls and injury among new workers, and demonstrate a potential target for intervention. Improving postural control strategies while on scaffolds might also reduce the amount of muscular and cardiovascular effort demanded during work tasks, and thereby reduce effects of fatigue at work.
However, we should note the limitations of the experiment. They used only 4 novices and 4 experts, and this limits the statistical power of the results. Further experiments should be conducted on larger sample sizes to confirm the validity of these results.
Perhaps future work could evaluate the impact of a training program for core and leg strength on improving postural control on scaffolds for both new employees, and for employees returning from a period of layoff.
Min, S-N, Kim, J-Y, Parnianpour, M. (2012). The effects of safety handrails and the heights of scaffolds on the subjective and objective evaluation of postural stability and cardiovascular stress in novice and expert construction workers. Applied Ergonomics, 43, 574-581.