Ergonomic Assessment of Lower-Limb Exoskeleton on Physiological Responses in Wildland Firefighters

Abstract

Wildland firefighters are exposed to sustained physical demands that impose substantial physiological and perceptual strain. Lower-limb exoskeletons have been proposed as assistive devices to reduce internal workload. However, their effectiveness in this occupational context remains unclear. This study evaluated the effects of a hip-based lower-limb exoskeleton on physiological responses during a treadmill protocol simulating locomotor demands in wildland firefighting. Six wildland firefighters completed a 60-min walking protocol including level, uphill, and downhill stages while wearing full personal protective equipment and a 20 kg backpack. Two experimental conditions were compared in randomized crossover design: exoskeleton assistance activated (EXO) and exoskeleton worn without assistance (NO EXO). Oxygen uptake (VO2), heart rate (HR), and rating of perceived exertion (RPE) were recorded throughout the protocol. All variables changed significantly over time (p<0.001), confirming the physiological and perceptual demands of the task. However, no significant main effect of condition was found for VO2, HR or RPE, and no condition × time interactions were observed (p>0.05). Descriptive analyses suggested slightly lower VO2 (−5.6%) and HR (−2.5%) with exoskeleton assistance, alongside a marginally higher RPE (+4.7%). These findings indicate that, under the present experimental conditions, hip-based exoskeleton assistance did not produce clear reductions in physiological strain during simulated wildland firefighting locomotion. Further studies with larger samples, longer familiarization periods, and field-based protocols are needed to determine whether specific tasks or device configurations may improve effectiveness.

Keywords: Hip-based Exoskeleton, Oxygen Consumption, Heart Rate, Perceived Exertion, Metabolic Demand, Physically Demanding Occupations

DOI: 10.54941/ahfe1007359