Does Work-Induced Fatigue Accumulate Across Three Compressed 12 Hour Shifts in Hospital Nurses and Aides?

Fatigue-related impairments in the nursing workforce contribute to a multitude of health, safety, and economic consequences at the individual, organizational and societal levels. Long and compressed work schedules are commonly worked in the healthcare industry, but more research is needed to understand the cumulative effects of multiple work shifts on physiology-based performance outcomes in nurses. The purpose of this study was to compare the effects of a single nursing work shift versus three compressed (one every 24 hours) 12 hour shifts on performance-based fatigue in nurses and aides. Twenty-six fulltime hospital working nurses and aides (age = 36.1 ± 13.3 years) reported to the lab for testing before, immediately after working a single 12 hour shift, and after working three 12 hour shifts in a 72 hour period. Outcome measures included vigilance-based reaction time, lapses of attention, and muscle function assessments (lower and upper body muscle strength, explosive strength and vertical jump performance). All variables except hand grip strength showed a significant decline following the three work shifts. The psychomotor vigilance reaction time and lapses of attention variables also generally showed a significant decline from the end of shift one to the end of shift three, indicting an accumulation of fatigue in these metrics with increasing number of shifts worked. Muscle function variables responded early in the duty cycle, showing a significant decline after a single work shift, but did no further decline by the end of the third shift. These findings use objective measures to substantiate that fatigue impairments occur from working a single 12 hour shift, and in several instances, increase further with more successive work shifts. Caution should be employed by personnel and administrators with work schedules involving multiple compressed 12 hour shifts. Fatigue management strategies may be used to improve risks and consequences from fatigue-related mishaps, and this study reports several variables that appear sensitive to identifying and tracking fatigue in this population

Fatigue and the Female Nurse: A Narrative Review of the Current State of Research and Future Directions

Background: The female nurse exhibits a multitude of personal and environmental characteristics that renders this population especially prone to fatigue. The consequences of fatigue in nurses are widespread and impactful at the personal, organizational, and societal levels. These include high injury rates and burnout in the nurse and poor patient and organizational outcomes. Objective: This article discusses the implications of fatigue in female nurses, including the impacts of fatigue across multiple entities (e.g., worker, patient, organization). It also reviews the current state of the research, including recent work on nurse fatigue and work schedule characteristics, and key areas for future work that would help empirically establish approaches to counter the detrimental and widespread effects of fatigue. Method: A narrative literature review was conducted resulting from an analysis of the literature limited to peer-reviewed studies. Results: A confluence of factors combines to elevate the prevalence and risk of fatigue in the female nurse. Numerous measures have established that performance-based fatigue results from nursing work schedules in nurses. Data also demonstrate that fatigue accumulates across successive shifts. Recent evidence supports the use of objective fatigue measures, including psychomotor reaction time and muscle function-related variables. Current gaps in the literature are delineated in the text. Conclusions: Strategic and well-designed research studies, as well as recent technological advances in fatigue tracking tools have the potential to help workers, administrators, and organizations develop fatigue management programs that could reduce the heavy burdens of fatigue on a multitude of health, safety, and economical outcomes. The influences of fatigue and its symptoms are of epidemic proportions. The consequences associated with fatigue apply indiscriminately to individuals of all ages, and across all social, educational, ethnic, racial, and economic demographics.1,2 Unsurprisingly, reports have revealed that at least some degree of fatigue is to be found in nearly all of the general or working populations.3–5 Since the symptoms of fatigue are presented along a continuum from negligible to severe67 The core factors that appear to contribute to the rampant impact of fatigue are (1) the high total prevalence of fatigue symptoms that are manifested in the population at large (e.g., Bultmann et al.3 reported that only 2% of a population of 12,095 identified as being completely free of fatigue) and (2) the relatively high proportion (∼40%–60%) of adults that exhibit severe fatigue levels.6,8,9 Although fatigue has been the subject of many reports across a multitude of domains—including physiology, psychology, sports science, military, and so on—relatively little has been reviewed with recent updates regarding physical fatigue in the context of the female nursing worker, and updates for future research directions would be warranted and timely. Given that the female nurse exhibits some unique vulnerabilities to fatigue and its consequences—due to interactions among biological, occupational, and environmental factors—further exploration into this area is of interest for researchers and practitioners. Thus, the aims of this review were to provide an overview of the implications of fatigue focusing on issues pertinent to the female nurse, a brief update on the current state of the research with a particular focus within the work schedule domain, and to provide future directions for research that could shed more light on areas less explored that remain poorly understood. This review will be focused on hospital-based nurses and aides, since this group accounts for a majority (∼60%) of working nurses and is characterized by unconventional, demanding work schedules (i.e., where 12-hour and rotating shifts are typical).1

Effect of Surface Stability on Core Muscle Activity During Dynamic Resistance Exercises

The purpose of this study was to compare core muscle activity during resistance exercises performed on stable ground versus an unstable surface and to examine whether lifting at different relative intensities affects core muscle activity levels. Twelve trained men performed four different movements including the deadlift, back squat, military press, and curl. Surface electromyography (EMG) was utilized to assess the activity of the rectus abdominis, external oblique, transversus abdominis, and erector spinae muscles. Participants performed each movement under three separate conditions including standing on stable ground with 50% of their one repetition maximum (1-RM), standing on a BOSU balance trainer with 50% of their 1-RM and, standing on stable ground with 75% of their 1-RM. The following muscles exhibited greater activity during the 75% 1-RM condition than all other conditions: the transversus abdominis (TA) and external oblique (EO) muscles during the deadlift; the rectus abdominis (RA) during the squat; the TA, RA, and EO during the press, and TA and erector spinae (ES) during the curl. The ES muscle during the press movement and EO during the squat movement were more active during the BOSU 50% 1-RM condition than the stable 50% 1-RM condition. Healthy individuals might consider performing the military press, curl, squat and deadlift movements with higher intensity resistances while standing on stable ground to incur higher widespread muscle activity of the core region

State Welfare-to-Work Policies for People with Disabilities

This study represents a first attempt to provide a nationwide overview of welfare-to-work policies for individuals with disabilities and caregivers. The major findings of this report are: (c) The majority of states have changed their work participation policies to require participation among some individuals with disabilities and caregivers who were previously exempt. (c) States are in the early stages of making decisions about who should be required to participate in welfare-to-work services, who should be expected to move off welfare within 60 months, and what services will best help recipients achieve this objective

Beyond and beneath the hierarchical market economy: global production and working-class conflict in Argentina's automobile industry

This paper argues that the hierarchical market economy (HME) category does not provide an adequate starting point for addressing capitalist diversity in Latin America. Building from a critical perspective on the global commodity chain (GCC) and global production network (GPN) approaches, it instead considers the impact of firms’ transnational relations and the often neglected role of working-class struggles. It will argue that capitalist diversity can only be understood at the nexus of these ostensibly global and local phenomena; and by specifying the strategic decisions taken by firms in Argentina’s automobile industry, it will account for the failure of that sector. Finally, it examines the role of working-class struggles in the industry in Córdoba, Argentina, arguing that these were vital in shaping the specific and unstable form of capitalist diversity in Argentina, as well as potential alternatives to it

Interaction Between Age and Fatigue on Antagonist Muscle Coactivation During an Acute Post-Fatigue Recovery Phase

This study investigated the age-related changes in antagonist muscle coactivation of the biceps femoris (BF) during an acute recovery period following a leg extensor fatiguing protocol. Twenty-three young (mean ± SD: age = 25.1 ± 3.0 years) and twenty-three old men (age = 71.5 ± 3.9 years) participated. Surface electromyography (sEMG) was recorded from the BF muscles for antagonist muscle coactivation. Testing invovled participants performing leg extension isometric maximal voluntary contractions (MVCs) and isokinetic MVCs at 240°•s-1 at baseline (Pre) and again after the fatigue protocol at 0 (Post0), 7 (Post7), 15 (Post15), and 30 (Post30) minutes post fatigue. Root mean square (RMS) values were computed from the BF sEMG and were calculated as the first 200 ms from onset for the isometric (IsomCoact200ms) and dynamic isokinetic 240°•s-1 (DynCoact200ms) MVCs, and for the final 10° of the leg extension (DynCoact10°) on the isokinetic 240°•-1 MVCs. Two-way ANOVAs [age group (young vs. old x time (Pre vs. Post0 vs. Post7 vs. Post15 vs. Post30)] showed that DynCoact200ms had an effect for time (p = 0.018), with greater antagonist coactivation in Pre than Post0 (p = 0.009) and recovering by Post7 (p = 0.011) with no group differences. Dyn Coact10° had no age x time interaction (p = 0.070), but had a main effect for time (p = 0.020) with the Post0 being lower than the Pre. However, for this variable the young group showed a more severe Pre to Post0 fatigue decline (-45.9%) than the old group (-6.7%) indicating this may be a more sensitive variable for capturing age-related antagonist coactivation post-fatigue responses. Leg extensor fatigue affects some BF coactivation sEMG variables more than others, and any altered post-fatigue coactivation response recovers rapidly ( \u3c 7 min) from baseline levels

Potential Benefits of a Minimal Dose Eccentric Resistance Training Paradigm to Combat Sarcopenia and Age-Related Muscle and Physical Function Deficits in Older Adults

The ability of older adults to perform activities of daily living is often limited by the ability to generate high mechanical outputs. Therefore, assessing and devloping maximal neuromuscular capacity is essential for determining age-related risk for functional decline as well as the effectiveness of therapeutic interventions. Interventions designed to enhance neuromuscular capacities underpinning maximal mechanical outputs could positively impact functional performace in daily life. Unfortunately, \u3c 10% of older adults meet the current resistance training guidelines. It has recently been proposed that a more minimal dose RT model may help engage a greater proprotion of older adults, so that they may realize the benefits of RT. Eccentric exercise offers some promising qualities for such an approach due to its efficiency in overloading contractions that can induce substantial neuromuscular adaptations. When used in a minimal dose RT paradigm, eccentric-based RT may be a particularly promising approach for older adults that can efficiently improve muscle mass, strength, and function capacities and overall health is through heightened exercise tolerance which would favor greater exercise participation in older adult populations. Therefore, our perspective article will discuss the implications of using a minimal dose, submaximal (i.e., low intensity) multi-join eccentric resistance training paradigm as a potentially effective, and yet currently underutilized, means to efficiently improve neuromuscular capacities and function for older adults

Interaction between age and fatigue on antagonist muscle coactivation during an acute post-fatigue recovery phase

PURPOSE: This study investigated the age-related changes in antagonist muscle coactivation of the biceps femoris (BF) during an acute recovery period following a leg extensor fatiguing protocol. METHODS: Twenty-three young (mean±SD: age=25.1±3.0 years) and twenty-three old men (age=71.5±3.9 years) participated. Surface electromyography (sEMG) was recorded from the BF muscles for antagonist muscle coactivation. Testing involved participants performing leg extension isometric maximal voluntary contractions (MVCs) and isokinetic MVCs at 240°·s-1 at baseline (Pre) and again after the fatigue protocol at 0 (Post0), 7 (Post7), 15 (Post15), and 30 (Post30) minutes post fatigue. Root mean square (RMS) values were computed from the BF sEMG and were calculated as the first 200ms from onset for the isometric (IsomCoact200ms) and dynamic isokinetic 240°·s-1 (DynCoact200ms) MVCs, and for the final 10º of the leg extension (DynCoact10°) on the isokinetic 240°·s-1 MVCs. Two-way ANOVAs (age group [young vs. old] × time [Pre vs. Post0 vs. Post7 vs. Post15 vs. Post30]) suggests that DynCoact200ms had an effect for time (p=0.018), with greater antagonist coactivation in Pre than Post0 (p=0.009) and recovering by Post7 (p=0.011) with no group differences. RESULTS: DynCoact10° exhibited a non-significant interaction (p=0.070), such that the young group exhibited an effect of time (p=0.017), with Post0 being lower than other time points but no effect for time for the old group (p=0.566). CONCLUSION: Following a fatiguing bout, DynCoact10° may be a more sensitive variable for capturing antagonist coactivation fatigue responses, and this finding may indicate older adults could have an impaired feedback mechanism in fatigue-induced dynamic movement tasks

Age-related effects of neuromuscular fatigue and recovery on voluntary maximal and rapid torque characteristics of the leg flexors and extensors in young and old men

The purpose of the present study was to examine the effects of acute neuromuscular fatigue and recovery on maximal and rapid torque characteristics in young and old men for the knee extensors and flexors. Twenty-one young (mean+/-SD:age=24.76 years) and nineteen old (age=72.05+/-3.60 years) men performed maximal voluntary contractions (MVCs) prior to performing a fatigue-inducing bout of sub-maximal, intermittent isometric contractions using a .6 duty cycle at 60% of MVC until volitional fatigue. MVCs were then performed again at immediately after, 7, 15, and 30min following the completion of the fatigue task. Endurance time was the elapsed time from onset until failure during the course of the fatigue protocol. Maximal (peak torque; PT) and rapid (absolute and relative rate of force development; RFD and nRFD, respectively) torque characteristics were calculated from the torque-time curves for each time period. Three-way mixed factorial ANOVAs (muscle [knee extensors vs leg flexors] x age [young vs old men] x time period [Pre vs Post vs Recovery 7 vs Recovery15, vs Recovery30) were used to analyze all maximal and rapid torque variables. The present findings revealed that older men had greater overall endurance times compared to young men. No differences were observed in the fatigue-induced reductions immediately following the fatigue task for the absolute rapid force characteristics among early and late phases of the torque-time curve, muscles, and age groups. However, differential recovery patterns were observed for PT, and early and late RTD phases between the knee extensor and flexor muscle groups such that the early rapid torque variables (RTD30 and RTD50) and the knee flexors demonstrated slower recovery compared to later rapid torque variables (>RFD100) and the knee extensors. The normalized RTD variables declined to a lesser extent following the fatigue task and differential muscle and group effects were observed where the knee flexors were reduced more at the early phase (nRTD1/6) compared to the knee extensors, however, for the later phase (nRTD2/3) the young men exhibited a significantly greater reduction compared to the old men. These findings may have important fatigue related performance, and injury risk implications for a variety of populations and settings

A Mixed-Methods Approach to Evaluating the Internal Validity of the Reactive Strength Index

The reactive capacity of the muscle-tendon complex is commonly assessed using the reactive strength index (RSI). Conventionally, the RSI is a ratio of rebound jump height to ground contact time in depth jumping. Several assumptions regarding the linear mechanics acting through the whole-body center of gravity may threaten the internal validity of computation and interpretation of RSI scores. First, it is common for rebound jump height to be predicted from rebound jump flight time. This assumes that the angular positioning of body segments is equivalent at the time instances of rebound jump take-off and landing. Prior literature supports a mixed-methods approach for computing the RSI that is void of this assumption. The mixed-methods approach gives a more valid estimation of rebound jump height. In this approach, rebound jump height is estimated from rebound jump take-off velocity of the whole-body center of mass. This is accomplished by subtracting an estimate of impact velocity, acquired using videography, from change in whole-body center of mass velocity estimated from integrated vertical ground reaction force data. Second, it is often assumed that vertical displacement of the whole-body center of mass during the drop phase of the depth jump is predicted perfectly from the height of the platform used to perform the drop. This assumption may affect the internal validity of comparing RSI scores across individuals and within individuals performing depth jumps from varied heights. The purpose of the present study was to investigate the internal validity of RSI scores computed using the conventional approach and impact velocity variability, which may affect the interpretation of RSI scores. Seventy physically active young adults performed depth jumps from drop heights of 0.51, 0.66, and 0.81 m. RSI was computed using the conventional approach and a mixed-methods approach featuring the use of 2-dimensional videography, body segment parameters, and force platform dynamometry. The two computational methods were compared using linear regression performed on data from each drop height. In addition, a 2 (computational method) by 3 (drop height) Analysis of Variance (ANOVA) was performed to evaluate for main effects and interactions in RSI data. Multiple one sample t-tests were performed to compare estimated and theoretical impact velocities. The ANOVA revealed no main effect or interactions between computational approaches (p = 0.467–0.938). Linear regression revealed moderately strong associations between RSI scores computed using the conventional and mixed-methods approaches (R2 = 0.685–0.741). Moreover, linear regressions revealed that the conventional approach tends to overestimate the mixed methods approach for RSI scores below 1.0 and underestimate the mixed methods approach for RSI scores above 1.0. Lastly, estimated impact velocities were observed to be as much as 13% lower versus theoretical (p \u3c 0.001). Researchers with access to motion capture and force platform technology may consider using a mixed-methods approach for computing the RSI, which likely maximizes the internal validity of scores. In addition, results suggest for practitioners to practice caution when comparing conventional RSI scores across individuals