Alternative footwear are those that are most commonly used for casual or recreational purposes, over the course of the day. The purpose of this study was to examine the effects of three forms of alternative footwear (thong style flip-flops, clog style Crocs®, and Vibram Five-Fingers®) on balance with a low-intensity workload. Eighteen healthy male adults (age: 22.9 ± 2.88 years; height: 179 ± 6.0 cm; mass: 81.3 ± 8.8 kg) participated in this study. Balance performance along with electromyographic (EMG) measures was assessed with sensory organization test (SOT) and motor control test on the Neurocom Equitest, while donning alternative footwear, prior to and after a one-mile walk at a self-selected pace. Sway velocities and root-mean-square sway, SOT equilibrium scores, postural response latencies, and EMG measures from lower leg muscles were analysed using a 3 × 2 (footwear × time) repeated-measures ANOVA. Results from balance variables revealed a significant main effect difference for footwear in the eyes closed and eyes open sway-referenced vision conditions and a significant main effect difference for time in the eyes open, eyes open sway-referenced vision, and eyes open sway-referenced platform conditions. Pairwise comparisons revealed MIN demonstrating significantly greater balance performance in the pretest condition and the post-test demonstrating significantly lower balance performance. Greater balance performance from MIN could be attributed to the barefoot design suggesting an increase in somatosensory feedback from the plantar surface, particularly during absent or conflicting visual feedback. The lower balance performance seen in post-test could be attributed to the one-mile walk, suggesting that even a transient physiological workload could be sufficient to cause balance decrements in alternative footwear.

Purpose: The objective of this review was to analyze the physiological impact of fire suppression on the human body. Design: The literature review included studies focused on workload requirements for common firefighting tasks, effect of health status on the firefighting profession, and attempts to establish a minimum physiological workload capacity for successful performance of firefighting. Findings: The existing literature provides evidence of the high degree of physiological stress that firefighters are under during fire suppression tasks and the great degree of maximal physical capacity that firefighting often requires. Firefighters often operate close to maximal aerobic capacity while performing tasks common to the profession. This is especially true due to the added physiological stress placed on the human body while wearing personal protective equipment during firefighting. Conclusions: Future investigations are necessary to further explore markers of physiological stress during firefighting and the impact that it may have on the ability to withstand the development of disease as well as fire suppression safety. Using completion time of fire suppression tasks as a criterion of success may be an important consideration in addition to the physiological requirements of the occupation when assessing the appropriateness of an individual to be a firefighter. An important future consideration is the effect that fire suppression activities may have on reaction time in critical situations in which life-and-death decisions must be made.

Purpose: The purpose of this study was to evaluate the agreement of five commercially available accelerometers in estimating energy expenditure while performing an acute bout of high-intensity functional training (HIFT). Methods: Participants (n = 47; average age: 28.5 ± 11.6 years) consisted of recreationally active, healthy adults. Each participant completed a session of HIFT: a 15-minute workout consisting of 12 repetitions each of air-squats, sit-ups, push-ups, lunges, pull-ups, steps-ups, and high-knees; performed circuit-style by completing as many rounds as possible. During this session, each participant wore the Cosmed K4b2 portable metabolic analyzer (PMA) and five different accelerometers (ActiGraph GT3X, Nike Fuelband, Fitbit One, Fitbit Charge HR, and Jawbone UP Move). Results: Four of the five activity trackers reported lower (p < .05) total EE values compared to the PMA during the acute bout of HIFT. The waist-mounted device (ActiGraph, 182.55 ± 37.93 kcal) was not significantly different from, and most closely estimated caloric expenditure compared to the PMA (144.99 ± 37.13 kcal) (p = .056). A repeated-measures ANOVA showed that all activity trackers were significantly different from the reference measure (PMA) (p < .05). Systematic relative agreement between the activity trackers was calculated, exhibiting a significant ICC = 0.426 (F [46,230] = 5.446 [p < .05]). Conclusion: The wrist- and hip-mounted activity trackers did not accurately assess energy expenditure during HIFT exercise. With the exception of the ActiGraph GT3X, the remaining four activity trackers showed inaccurate estimates of the amount of kilocalories expended during the HIFT exercise bout compared to the PMA.

BACKGROUND: The impact of occupational footwear and workload on postural stability has been studied previously to prevent fall-related workplace injuries. OBJECTIVE: The purpose of this study was to assess the impact of two types of occupational footwear [steel-toed (SB) and tactical (TB) work boots] on human balance, when exposed to physical workload. METHODS: Postural stability was evaluated in eighteen male participants in the following conditions: eyes open (EO), eyes closed (EC), eyes open unstable surface (EOU) and eyes closed unstable surface (ECU). Postural sway parameters were analyzed using a 2×3 repeated measures analysis of variance design [prior to (PRE) and twice post-workload (POST1 & POST2) separated by 10 minutes of rest]. RESULTS: Findings revealed that the use of SB resulted in greater postural stability, which could be attributed to the design characteristics of these footwear and that postural stability was negatively impacted immediately after the workload which could be attributed to the physical exertions during the workload. However, significant differences were limited to ECU with no visual and altered somatosensory feedback. CONCLUSION: Design features on occupational footwear can aid postural stability while physical exertional tasks can be detrimental. Findings can offer design and work-rest scheduling suggestions to improve work safety.

Morris, CE, Arnett, SW, and Winchester, LJ. Comparing physical fitness in career vs. volunteer firefighters. J Strength Cond Res 36(5): 1304–1309, 2022—The purpose of this study was to assess the potential similarities and differences in health and physical fitness profiles between career firefighters (CFF) and volunteer firefighters (VFF). The research protocol consisted of a health and physical fitness assessment, testing the 5 components of health-related fitness using previously published and accepted protocols. The subject population consisted of a total of 138 firefighters, including 119 CFF and 19 VFF. Statistical significance was defined as a p level less than 0.05. An independent t test showed evidence of CFF having a significantly higher value/score for the following variables: height (p = 0.034), V̇o ₂max (p = 0.006), push-ups completed (p = 0.024), and plank time (p < 0.001). Volunteer firefighters had a significantly higher value for the following variables: fat mass (p = 0.002), body fat percentage (p < 0.001), and absolute grip strength (p = 0.029). There were no significant differences between groups for the following variables: age (p = 0.299), body mass (p = 0.166), fat-free mass (p = 0.281), body mass index (p = 0.057), flexibility (p = 0.106), or relative grip strength (p = 0.887). With regard to physical fitness testing, the VFF had a significantly worse fitness profile across a number of variables than the CFF. Practical applications: Despite the financial and commitment status of volunteer firefighting departments, their members perform an equally dangerous and important job as do firefighters of professional/career firefighting departments, and more attention should be directed toward developing the fitness and performance of these firefighters.

Background. This study aimed to evaluate the physiological strain index (PSI) along with specific immune system markers in response to a simulated firefighting occupation workload. Methods. Ten healthy male adults completed a 6-min simulated fire stair climb (SFSC) at 60 steps/min. The protocol consisted of four conditions, some including wearing a 34.04-kg vest to simulate personal protective equipment (PPE) and/or inclusion of a color-word interference test (CWIT) as a distracting mechanism. The PSI was evaluated by continuously monitoring the heart rate and core temperature. Salivary cortisol (CORT) was measured at baseline, mid SFSC and post SFSC. C-reactive protein (CRP) was evaluated at baseline and 1 h post SFSC. Results. Repeated-measures analysis of variance showed a significantly different PSI across conditions (p = 0.001). A significantly elevated PSI was exhibited during all 6 min of SFSC for both PPE and PPE + CWIT conditions. Neither CORT (p = 0.116) nor CRP (p = 0.700) was significantly different across conditions or from baseline. Conclusion. These findings suggest that firefighters are potentially at a substantial degree of physiological stress from exercise and the weight of gear alone. Further work should be conducted to further evaluate the usefulness of the PSI as a means to monitor firefighters during fire suppression.