Fatigue-induced balance alterations in a group of Italian career and retained firefighters

摘要

Firefighters (FFs) often work in hazardous and physically-demanding environments, and injuries related to loss of balance are common among them. This study examined the postural balance of FFs with different levels of experience and training, both before and after simulated physically-demanding and fatiguing firefighting and rescue activities. Balance was assessed in two FF groups (career and "retained", n = 13 each), on the basis of center-of-pressure (COP) time series that were acquired using a pressure platform during quiet upright stance. Several traditional COP-based measures (mean COP velocity and sway area) were derived. In addition, and to quantify the dynamical properties of postural control, complexity of the COP time series was determined using the multiscale entropy (MSE) method. Both age and the annual number of working days were higher for career FFs, though both groups had comparable levels of pre-activity balance. Post-activity changes in balance were also generally comparable between the groups, except that retained FFs exhibited a significantly higher post-activity loss of COP complexity in the medial-lateral direction. These results suggest that experience and training may serve to offset age-related decrements in postural balance, and implications for the risk of balance-related injuries during firefighting operations are discussed. Relevance to industry: Objective assessment of physical capacities in firefighters may be of value to design training programs suitable to meet job demands and avoid injury.