Effects of an exoskeleton on muscle activity in tasks requiring arm elevation: Part I - Experiments in a controlled laboratory setting.

Background: Long-term work with elevated arms, or overhead work, is a risk factor for musculoskeletal complaints and disorders. Upper-limb exoskeletons are a promising tool for reducing occupational workload when working with hands above shoulder level.

Objective: The purpose of this study was to assess the effects of upper-limb exoskeleton on muscular and physical strain and perceived exertion during dynamic work at four different shoulder joint angles.

Interventions to promote work ability by increasing physical activity among workers with physically strenuous jobs: A scoping review.

: The potential benefits of workplace physical activity (PA) interventions are in improving both health and important workplace outcomes. Despite the differences in PA level between physically strenuous and inactive work, the literature reporting the effectiveness of the interventions does not usually differentiate physically active and inactive jobs. The aim of the current study was therefore to collect and synthesise research evidence on workplace PA interventions to promote work ability specifically among workers in physically strenuous jobs by means of a scoping review.

The effect of mild whole-body cold stress on isometric force control during hand grip and key pinch tasks.

Prolonged exposure to cold can impair manual performance, which in turn can affect work task performance. We investigated whether mild whole-body cold stress would affect isometric force control during submaximal hand grip and key pinch tasks. Twelve male participants performed isometric hand grip and key pinch tasks at 10% and 30% of maximal voluntary contraction (MVC) for 30 and 10 s respectively, in cold (8 °C) and control (25 °C) conditions.

Thermoregulation and shivering responses in elite alpine skiers.

This study aimed to characterise the thermoregulatory responses of elite alpine skiers. Core (gastro-intestinal) and skin temperatures were recorded continuously from 4 national team skiers representing 18 training-sessions for a total of 83 ski runs (average ambient temperature 1.9°C).

Activity Level and Body Mass Index as Predictors of Physical Workload During Working Career.

The increasing prevalence of inactivity and obesity, along with aging, has implications on work capacity of labor force. This study reports the relationships between activity level and BMI by age with objectively measured physical workload. Data were examined from a sample of 19 481 Finnish employees using an estimate of minute-to-minute oxygen consumption based on R-R interval recordings.

Head Movements and Neck Muscle Activity During Air Combat Maneuvering.

The aim of the study was to determine the characteristics of cervical muscle activity in different head movements when using helmet mounted display in air combat maneuvering. Cervical EMG was measured with eight F/A-18 pilots using the Joint Helmet Mounted Cueing System (JHMCS) during air combat maneuvering. In-flight G acceleration and continuous head position were recorded.

Interventions to promote work ability by increasing sedentary workers' physical activity at workplaces - A scoping review.

Although worksite interventions increase physical activity, little is known about their effects on work ability. The objective of this scoping review was to examine the extent, range and nature of interventions to promote work ability by increasing the physical activity or decreasing the sedentary time of sedentary workers in order to identify implications for health promotion at workplaces. We searched Medline, Cochrane Central, and Scopus and identified 29 intervention studies.

Joint Helmet-Mounted Cueing System and Neck Muscle Activity During Air Combat Maneuvering.

The aim of the study was to determine the characteristics of cervical muscle activity in different head postures when using helmet-mounted display in one fighter vs. two aircraft air combat within visual range (WVR). Cervical EMG was measured with eight F/A-18 pilots using the Joint Helmet Mounted Cueing System (JHMCS) during air combat maneuvering.

Diurnal variation in repeated sprint performance cannot be offset when rectal and muscle temperatures are at optimal levels (38.5°C).

The present study investigated whether increasing morning rectal temperatures (T) to evening levels, or increasing morning and evening T to an "optimal" level (38.5°C), resulting in increased muscle temperatures (T), would offset diurnal variation in repeated sprint (RS) performance in a causal manner. Twelve trained males underwent five sessions [age (mean ± SD) 21.

Controlling rectal and muscle temperatures: Can we offset diurnal variation in repeated sprint performance?

The present study investigated whether increasing morning rectal temperatures (T) to resting.evening levels, or decreasing evening T or muscle (T) temperatures to morning values, would influence repeated sprint (RS) performance in a causal manner. Twelve trained males underwent five sessions [age (mean ± SD) 21.

Social participation and heat-related behavior in older adults during heat waves and on other days.

Background: High indoor temperatures require behavioral adaptation, especially among vulnerable older adults. There are uncertainties as to the degree to which people adapt to these challenging conditions.

Objective: The aim of this study was to describe the degree of adaptation of social participation and other heat-related behavior with respect to higher indoor temperatures.

Effect of Indoor Temperature on Physical Performance in Older Adults during Days with Normal Temperature and Heat Waves.

Indoor temperature is relevant with regard to mortality and heat-related self-perceived health problems. The aim of this study was to describe the association between indoor temperature and physical performance in older adults. Eighty-one older adults (84% women, mean age 80.

Neck and Shoulder Muscle Activation Among Experienced and Inexperienced Pilots in +Gz Exposure.

Background: The aim of the present study was to compare differences in electromyography (EMG) activation of the neck and shoulder muscles between groups of inexperienced and experienced pilots during controlled +Gz exposure in a centrifuge.

Methods: The subjects were volunteer cadets (inexperienced group) and lieutenants (experienced group) undergoing their first centrifuge training. The first group did not have any high performance aircraft (HPA) experience, while the latter one had a 1-yr experience of intense flying of HPA.

Thermal stress, human performance, and physical employment standards.

Many physically demanding occupations in both developed and developing economies involve exposure to extreme thermal environments that can affect work capacity and ultimately health. Thermal extremes may be present in either an outdoor or an indoor work environment, and can be due to a combination of the natural or artificial ambient environment, the rate of metabolic heat generation from physical work, processes specific to the workplace (e.g.

Multivariate statistical assessment of predictors of firefighters' muscular and aerobic work capacity.

Physical capacity has previously been deemed important for firefighters physical work capacity, and aerobic fitness, muscular strength, and muscular endurance are the most frequently investigated parameters of importance. Traditionally, bivariate and multivariate linear regression statistics have been used to study relationships between physical capacities and work capacities among firefighters. An alternative way to handle datasets consisting of numerous correlated variables is to use multivariate projection analyses, such as Orthogonal Projection to Latent Structures.

Effect of a brief heat exposure on blood pressure and physical performance of older women living in the community-a pilot-study.

Global climate change is affecting health and mortality, particularly in vulnerable populations. High ambient temperatures decrease blood pressure (BP) in young and middle aged adults and may lead to orthostatic hypotension, increasing the risk of falls in older adults. The aim of this study was to evaluate the feasibility of a test protocol to investigate BP response and aerobic capacity of older adults in a hot indoor environment.

Self-rated physical loads of work tasks among firefighters.

Objectives: The present study sought to identify firefighters' rated physical demands for the most frequently occurring work tasks and to determine if the ratings differed between full-time and part-time firefighters to help create a basis for the development of physical employment tests for firefighters.

Methods: An extensive questionnaire was completed by 125 and 68 firefighters in 2000 and 2010, respectively. The data were analysed with the Mann-Whitney U test and binominal test and ranked on the basis of the responses in each category.

Effect of cold indoor environment on physical performance of older women living in the community.

Background: the effects of cold on older persons' body and mind are not well documented, but with an increased number of older people with decreasing physical performance, these possible effects need to be understood.

Objective: to investigate the effect of cold indoor environment on physical performance of older women.

Design: cross-sectional experimental study with two test conditions.

Muscular, cardiorespiratory and thermal strain of mast and pole workers.

This field study evaluated the level of muscular, cardiorespiratory and thermal strain of mast and pole workers. We measured the muscular strain using electromyography (EMG), expressed as a percentage in relation to maximal EMG activity (%MEMG). Oxygen consumption (VO2) was indirectly estimated from HR measured during work and expressed as a percentage of maximum VO2 (%VO2max).

Laboratory or field tests for evaluating firefighters' work capacity?

Muscle strength is important for firefighters work capacity. Laboratory tests used for measurements of muscle strength, however, are complicated, expensive and time consuming. The aims of the present study were to investigate correlations between physical capacity within commonly occurring and physically demanding firefighting work tasks and both laboratory and field tests in full time (N = 8) and part-time (N = 10) male firefighters and civilian men (N = 8) and women (N = 12), and also to give recommendations as to which field tests might be useful for evaluating firefighters' physical work capacity.

Fuel selection during short-term submaximal treadmill exercise in the cold is not affected by pre-exercise low-intensity shivering.

Exercise and shivering rely on different metabolic pathways and consequently, fuel selection. The present study examined the effects of a pre-exercise low-intensity shivering protocol on fuel selection during submaximal exercise in a cold environment. Nine male subjects exercised 4 times for 60 min at 50% (LOW) or 70% (MOD) of their peak oxygen consumption on a motorized treadmill in a climatic chamber set at 0 °C with (SHIV) and without (CON) a pre-exercise cooling protocol, inducing low-intensity shivering.

Field tests for evaluating the aerobic work capacity of firefighters.

Working as a firefighter is physically strenuous, and a high level of physical fitness increases a firefighter's ability to cope with the physical stress of their profession. Direct measurements of aerobic capacity, however, are often complicated, time consuming, and expensive. The first aim of the present study was to evaluate the correlations between direct (laboratory) and indirect (field) aerobic capacity tests with common and physically demanding firefighting tasks.

Effect of cold conditions on double poling sprint performance of well-trained male cross-country skiers.

This study compared the effects of cold (-14° C) and moderate environments (6° C) on double poling (DP) sprint performance. Wearing modern cross-country ski racing suits, 14 highly trained male cross-country skiers performed a test protocol on a DP ergometer, consisting of a standardized warm-up followed by a 30-second maximal sprint (DP30s) and a 2-minute maximal sprint (DP2min), and after an 8-minute recovery period, another DP30s and DP2min were performed. Finally, the participants performed an incremental DP test to exhaustion.

Firefighters muscular recovery after a heavy work bout in the heat.

Occasionally firefighters need to perform very heavy bouts of work, such as smoke diving or clearing an accident site, which induce significant muscle fatigue. The time span for muscular recovery from such heavy work is not known. The purpose of this study was to evaluate firefighters' force-, neural-, metabolic-, and structural-related recovery after task-specific heavy work in the heat.