Abstract: The aim of the study was to determine whether indoor lighting and colour would have any systematic impact on the mood of people working indoors. Earlier studies have mostly focused either on light, colour or windows in laboratory settings. The present study was carried out in real work environments at different seasons and in countries with different latitudes. A total of 988 persons completed all parts of the study. In the countries situated far north of the equator there was a significant variation in psychological mood over the year that did not occur in the countries closer to the equator. When all four countries were considered together, it became evident that the light and colour of the workplace itself also had an influence on the mood of persons working there. The workers' mood was at its lowest when the lighting was experienced as much too dark. The mood then improved and reached its highest level when the lighting was experienced as just right, but when it became too bright the mood declined again. On the other hand, the illuminance as measured in objective terms, showed no significant impact on mood at any time of the year. The relationship between mood and the distance to the nearest window was bimodal. The results also indicate that the use of good colour design might contribute to a more positive mood. It is suggested that in future research light and colour should be studied as parts of the more complex system making up a healthy building.

Abstract: Decentralized command and control settings like those found in the military are rife with complexity and change These settings typically involve dozens, if not hundreds to thousands, of heterogeneous players coordinating in a distributed fashion in a dynamically networked battlefield laden with sensor data, intelligence reports, communications, and plans emanating from many different perspectives Consider the concept of team situation awareness in this setting What does it mean for a team to be aware of a situation or, more importantly, of a critical change in a situation? Is it sufficient or necessary for all individuals on the team to be independently aware? Or is there some more holistic awareness that emerges as team members interact? We re-examine the concept of team situation awareness in decentralized systems beyond an individual-oriented knowledge-based construct by considering it as a team interaction-based phenomenon A theoretical framework for a process-based measure called ‘coordinated awa

Abstract: Military personnel are required to carry heavy loads whilst marching; this load carriage represents a substantial component of training and combat. Studies in the literature mainly concentrate on physiological effects, with few biomechanical studies of military load carriage systems (LCS). This study examines changes in gait and posture caused by increasing load carriage in military LCS. The four conditions used during this study were control (including rifle, boots and helmet carriage, totalling 8 kg), webbing (weighing 8 kg), backpack (24 kg) and a light antitank weapon (LAW; 10 kg), resulting in an incremental increase in load carried from 8, 16, 40 to 50 kg. A total of 20 male soldiers were evaluated in the sagittal plane using a 3-D motion analysis system. Measurements of ankle, knee, femur, trunk and craniovertebral angles and spatiotemporal parameters were made during self-paced walking. Results showed spatiotemporal changes were unrelated to angular changes, perhaps a consequence of military training. Knee and femur ranges of motion (control, 21.1 degrees +/- 3.0 and 33.9 degrees +/- 7.1 respectively) increased (p < 0.05) with load (LAW, 25.5 degrees +/- 2.3 and 37.8 degrees +/- 1.5 respectively). The trunk flexed significantly further forward, confirming results from previous studies. In addition, the craniovertebral angle decreased (p < 0.001) indicating a more forward position of the head with load. It is concluded that the head functions in concert with the trunk to counterbalance load. The higher muscular tensions necessary to sustain these changes have been associated with injury, muscle strain and joint problems.

Abstract: This study examined the effects of loudness and tempo of background music on exercise performance A total of 30 volunteers performed five 10-min exercise sessions on a treadmill The music listened to whilst exercising was either fast/loud, fast/quiet, slow/loud, slow/quiet or absent Measures of running speed, heart rate, perceived exertion and affect were taken Significant effects and interactions were found for running speed and heart rate across the different music tempo and loudness levels More positive affect was observed during the music condition in comparison to the 'no music' condition No significant differences for perceived exertion were found across conditions These results confirm that fast, loud music might be played to enhance optimal exercising, and show how loudness and tempo interact

Abstract: There is incomplete information about how physically demanding rescue work may be. The aim therefore of this paper was to examine the physiological responses of firefighters during a simulated rescue of hospital patients and to relate the firefighters' performance to their endurance, strength and working technique. Fourteen part-time male firefighters with a maximal oxygen uptake (VO(2max)) of 4.4 +/- 0.3 l/min (mean +/- SD) served as subjects in this study. First, each firefighter ascended six floors (a 20.5 m vertical ascent) carrying tools, wearing protective clothing and a breathing apparatus, an extra mass of 37 kg. He thereafter 'rescued' six persons by dragging each person on a fire-sheet on a flat floor. The technique used was recorded and the O(2) uptake and the heart rate were measured continuously during the whole operation. The blood lactate concentration and the subjective rating of perceived exertion were measured during and just after the rescue. The VO(2max) and the muscle strength were measured in the laboratory. The whole operation was carried out in the course of 5-9 min. The operation was a virtual all-out effort and the peak blood lactate concentration was 13 +/- 3 mmol/l. The peak oxygen uptake was 3.7 +/- 0.5 l/min (84% of the VO(2max)) during the operation. Large and heavy firefighters carried out the task faster than smaller ones. The VO(2max) in absolute terms and the dragging technique used were both related to the rescue performance. Rescuing patients at a hospital was physically very demanding and the time needed to complete the task depended on the VO(2max) in absolute values and the working technique used. A minimum VO(2max) of 4 l/min for firefighters was recommended.

Abstract: There is increasing interest in the use of social network analysis as a tool to study the performance of teams and organizations. In this paper, processes of command and control in the emergency services are explored from the perspective of social network theory. We report a set of network analyses (comprising visualization, a selection of mathematical metrics, and a discussion of procedures) based on the observation of six emergency service incidents: three fire service operations involving the treatment of hazardous chemicals, and three police operations involving immediate response to emergency calls. The findings are discussed in terms of our attempts to categorize the network structures against a set of extant command and control network archetypes and the relationship between those structures; comments on the qualities the networks display are put into the contexts of the incidents reported. We suggest that social network analysis may have a valuable part to play in the general study of command and control.

Abstract: This study investigated the association between slip severity and pre-slip gait characteristics of younger and older subjects. Sixteen younger and eleven older healthy adults walked onto an unexpectedly slippery surface. Slip severity was categorized as either hazardous or non-hazardous using a 1.0 ms peak slip velocity threshold. The results showed that hazardous slips were associated with greater step lengths (normalized by leg length) (SLR), larger and more rapidly changing foot - floor angles (FFA) at heel strike, and increased cadence across the two subject groups. Older subjects were found to walk with shorter SLR and with smaller and more slowly changing FFA at heel strike compared to younger subjects. However, both younger and older subjects experienced hazardous slips at the same rate. A logistic regression model relating SLR and cadence to slip severity predicted that increased SLR and decreased cadence would result in increased probability of hazardous slip (R2 = 0.45, chi2 = 15.30, p<0.01). A second logistic regression model relating FFA with slip severity predicted that increased FFA would result in increased probability of hazardous slip (R2 = 0.53, chi2 = 16.55, p<0.01). These results suggest that gait characteristics prior to foot contact play an important role in the severity of an ensuing slip. The finding that older adults experienced hazardous slips at the same rate as young adults even though their SLR and FFA are smaller suggests that age is also playing a role in other aspects of postural control that impact slip severity.

Abstract: The aim of this study was to find out what are the effects of three different sound environments on performance of cognitive tasks of varying complexity. These three sound environments were 'speech', 'masked speech' and 'continuous noise'. They corresponded to poor, acceptable and perfect acoustical privacy in an open-plan office, respectively. The speech transmission indices were 0.00, 0.30 and 0.80, respectively. Sounds environments were presented at 48 dBA. The laboratory experiment on 36 subjects lasted for 4 h for each subject. Proofreading performance deteriorated in the 'speech' (p < 0.05) compared to the other two sound environments. Reading comprehension and computer-based tasks (simple and complex reaction time, subtraction, proposition, Stroop and vigilance) remained unaffected. Subjects assessed the 'speech' as the most disturbing, most disadvantageous and least pleasant environment (p < 0.01). 'Continuous noise' annoyed the least. Subjective arousal was highest in 'masked speech' and lowest in 'continuous noise' (p < 0.05). Performance in real open-plan offices could be improved by reducing speech intelligibility, e.g. by attenuating speech level and using an appropriate masking environment.

Abstract: In order to determine differences in biomechanical risk factors across computer tasks, a repeated measures laboratory experiment was completed with 30 touch-typing adults (15 females and 15 males). The participants completed five different computer tasks: typing text, completing an html-based form with text fields, editing text within a document, sorting and resizing objects in a graphics task and browsing and navigating a series of intranet web pages. Electrogoniometers and inclinometers measured wrist and upper arm postures, surface electromyography measured muscle activity of four forearm muscles and three shoulder muscles and a force platform under the keyboard and force-sensing computer mouse measured applied forces. Keyboard-intensive tasks were associated with less neutral wrist postures, larger wrist velocities and accelerations and larger dynamic forearm muscle activity. Mouse-intensive tasks (graphics and intranet web page browsing) were associated with less neutral shoulder postures and less variability in forearm muscle activity. Tasks containing a mixture of mouse and keyboard use (form completion and text editing) were associated with higher shoulder muscle activity, larger range of motion and larger velocities and accelerations of the upper arm. Comparing different types of computer work demonstrates that mouse use is prevalent in most computer tasks and is associated with more constrained and non-neutral postures of the wrist and shoulder compared to keyboarding.

Abstract: C4i is defined as the management infrastructure needed for the execution of a common goal supported by multiple agents in multiple locations and technology. In order to extract data from complex and diverse C4i scenarios a descriptive methodology called Event Analysis for Systemic Teamwork (EAST) has been developed. With over 90 existing ergonomics methodologies already available, the approach taken was to integrate a hierarchical task analysis, a coordination demand analysis, a communications usage diagram, a social network analysis, and the critical decision method. The outputs of these methods provide two summary representations in the form of an enhanced operation sequence diagram and a propositional network. These offer multiple overlapping perspectives on key descriptive constructs including who the agents are in a scenario, when tasks occur, where agents are located, how agents collaborate and communicate, what information is used, and what knowledge is shared. The application of these methods to live data drawn from the UK rail industry demonstrates how alternative scenarios can be compared on key metrics, how multiple perspectives on the same data can be taken, and what further detailed insights can be extracted. The ultimate aim of EAST is, by applying it across a number of scenarios in different civil and military domains, to provide data to develop generic models of C4i activity and to improve the design of systems aimed at enhancing this management infrastructure.

Abstract: Slips, trips and falls present the greatest risk to in-patients in terms of exposure (frequency of occurrence) but only present a low severity risk in terms of mortality. The risk factors have been categorized as intrinsic (individual to the patient, e.g. visual impairment, balance problems and medicine use) or extrinsic (environmental). Many recommendations have been made concerning the management of environmental hazards but, of these, only beds rails have supporting research evidence. Other recommendations include patient assessment, footwear, flooring, lighting, staffing levels and bed alarms. However, three systematic reviews and the current narrative review have all failed to find research evaluating the benefits of these recommendations. The most robust evidence relates to the use of bed rails. This research suggests that bed rails not only fail to reduce the frequency of falls, but may also exacerbate the severity of injury. As Maslow's Hierarchy of Needs model has been used as a framework for nursing models of care, it was chosen as the basis for the development of an environmental hazard assessment model. The environmental hazards are revisited using this model in order to take an ergonomic or patient-centred approach for risk assessment.

Abstract: Medication errors are a leading cause of unintended harm to patients, both in Australia and internationally, and there is now a concerted attempt to identify and correct individual and workplace factors that encourage medication errors. The current study used structural equation modelling to measure organizational climate and to test a model with hypothesized links between climate and unsafe medication administration behaviours. The study also examined the possible mediating role of stress and morale. Data were collected from 176 nurses working in rural areas in Australia. The model provided a reasonable fit to the data with organizational climate accounting for 39% of the variance in individual distress, which in turn explained 7% of the variance in self-reported violations. The only variable that made a direct contribution to errors was violations, which accounted for 24% of the variance in medication errors. These findings highlight the importance of monitoring the state of the whole health system. Deficiencies at the organizational level affect the psychological well-being of hospital employees, and distressed employees are more likely to engage in substandard work practices that ultimately endanger the patients under their care.

Abstract: Previous research has shown that the presentation of spatially predictive auditory and vibrotactile warning signals can facilitate driver responses to driving events seen through the windscreen or rearview mirror. The present study investigated whether this facilitation reflects the priming of the appropriate response (i.e. braking vs. accelerating) or an attentional cuing effect (i.e. a perceptual benefit that facilitates subsequent behavioural responding). In the experiments reported here, participants had to discriminate the colour of a number plate (red vs. blue) following the presentation of either spatially predictive vibrotactile (experiment 1) or auditory (experiment 2) warning signals that indicated the likely location (front or back) of the visual target, while simultaneously performing a highly attention-demanding rapid serial visual presentation task. Numberplate discrimination performance was facilitated following the presentation of valid auditory cues, but not following the presentation of equally informative vibrotactile cues. The use of an orthogonal spatial cuing design enabled with us to rule out of a potential response priming account of these data. The results suggest that whilst directional congruency between a warning signal and a target event may be sufficient to facilitate performance due to the priming of the appropriate response, attentional facilitation effects may also require the co-location of the cue and target within the same functional region of space.

Abstract: To examine the effects of firefighting personal protective ensemble (PPE) and self-contained breathing apparatus (SCBA) on exercise performance, 12 males completed two randomly ordered, graded exercise treadmill tests (GXTPPE and GXTPT). Maximal oxygen consumption (VO2max) during GXTPPE was 17.3% lower than the GXTPT in regular exercise clothing (43.0 ± 5.7 vs. 52.4 ± 8.5 ml/kg per min, respectively). The lower VO2max during the PPE condition was significantly related (r = 0.81, p < 0.05) to attenuated peak ventilation (142.8 ± 18.0 vs. 167.1 ± 15.6 l/min), which was attributed to a significant reduction in tidal volume (2.6 ± 10.4 vs. 3.2 ± 0.4 l). Breathing frequency at peak exercise was unchanged (55 ± 7 vs. 53 ± 7 breaths/min). The results of this investigation demonstrate that PPE and the SCBA have a negative impact on VO2max. These factors must be considered when evaluating aerobic demands of fire suppression work and the fitness levels of firefighters.

Abstract: Localized muscle fatigue has received growing attention as a potential design variable and exposure metric in research towards prevention of musculoskeletal disorders in the workplace. While fatigue during sustained static work has been investigated extensively, effects during tasks comprising work-rest cycles are less clear. Work-rest models for static intermittent work have been presented in several reports, but the applicability is often limited to specific conditions. A study was conducted that facilitated a description of the relationships between static intermittent efforts and muscle endurance and fatigue. Exercises consisted of 1 h (maximum) of repetitive static arm abductions, involving a range of muscle contraction levels (10-30% maximum voluntary exertion), duty cycles (0.2-0.8) and cycle times (20-180 s). A between-subject central composite experimental design was used and 15 different exercise conditions were examined with six participants (three females and three males) for each. Along with endurance times, temporal changes related to fatigue were monitored using muscle strength, ratings of discomfort and electromyography (EMG) obtained from the middle-deltoid muscle during the contraction phase of the work cycles. The results of this study showed the influence of contraction level and duty cycle on the majority of fatigue measures used, while cycle time tended to affect EMG spectral measures. Using a response surface methodology, several fatigue prediction models and contour plots were developed that can be employed as an aid for design and evaluation of light repetitive static tasks. Good correspondence was generally found between discomfort rating and other measures of fatigue, suggesting the usefulness of this measure for rapid assessments of local fatigue in the workplace.

Abstract: Car drivers show an acute sensitivity towards vehicle feedback, with most normal drivers able to detect 'the difference in vehicle feel of a medium-size saloon car with and without a fairly heavy passenger in the rear seat' (Joy and Hartley 1953-54). The irony is that this level of sensitivity stands in contrast to the significant changes in vehicle 'feel' accompanying modern trends in automotive design, such as drive-by-wire and increased automation. The aim of this paper is to move the debate from the anecdotal to the scientific level. This is achieved by using the Brunel University driving simulator to replicate some of these trends and changes by presenting (or removing) different forms of non-visual vehicle feedback, and measuring resultant driver situational awareness (SA) using a probe-recall method. The findings confirm that vehicle feedback plays a key role in coupling the driver to the dynamics of their environment (Moray 2004), with the role of auditory feedback particularly prominent. As a contrast, drivers in the study also rated their self-perceived levels of SA and a concerning dissociation occurred between the two sets of results. Despite the large changes in vehicle feedback presented in the simulator, and the measured changes in SA, drivers appeared to have little self-awareness of these changes. Most worryingly, drivers demonstrated little awareness of diminished SA. The issues surrounding vehicle feedback are therefore similar to the classic problems and ironies studied in aviation and automation, and highlight the role that ergonomics can also play within the domain of contemporary vehicle design.

Abstract: The effectiveness of intermittent, microclimate cooling for men who worked in US Army chemical protective clothing (modified mission-oriented protective posture level 3; MOPP 3) was examined. The hypothesis was that intermittent cooling on a 2 min on-off schedule using a liquid cooling garment (LCG) covering 72% of the body surface area would reduce heat strain comparably to constant cooling. Four male subjects completed three experiments at 30 degrees C, 30% relative humidity wearing the LCG under the MOPP 3 during 80 min of treadmill walking at 224 +/- 5 W . m(-2). Water temperature to the LCG was held constant at 21 degrees C. The experiments were; 1) constant cooling (CC); 2) intermittent cooling at 2-min intervals (IC); 3) no cooling (NC). Core temperature increased (1.6 +/- 0.2 degrees C) in NC, which was greater than IC (0.5 +/- 0.2 degrees C) and CC (0.5 +/- 0.3 degrees C) ( p < 0.05). Mean skin temperature was higher during NC (36.1 +/- 0.4 degrees C) than IC (33.7 +/- 0.6 degrees C) and CC (32.6 +/- 0.6 degrees C) and mean skin temperature was higher during IC than CC ( p < 0.05). Mean heart rate during NC (139 +/- 9 b . min(-1)) was greater than IC (110 +/- 10 b . min(-1)) and CC (107 +/- 9 b . min(-1)) ( p < 0.05). Cooling by conduction (K) during NC (94 +/- 4 W . m(-2)) was lower than IC (142 +/- 7 W . m(-2)) and CC (146 +/- 4 W . m(-2)) ( p < 0.05). These findings suggest that IC provided a favourable skin to LCG gradient for heat dissipation by conduction and reduced heat strain comparable to CC during exercise-heat stress in chemical protective clothing.

Abstract: Theoretical analyses of air traffic complexity were carried out using the Method for the Analysis of Relational Complexity. Twenty-two air traffic controllers examined static air traffic displays and were required to detect and resolve conflicts. Objective measures of performance included conflict detection time and accuracy. Subjective perceptions of mental workload were assessed by a complexity-sorting task and subjective ratings of the difficulty of different aspects of the task. A metric quantifying the complexity of pair-wise relations among aircraft was able to account for a substantial portion of the variance in the perceived complexity and difficulty of conflict detection problems, as well as reaction time. Other variables that influenced performance included the mean minimum separation between aircraft pairs and the amount of time that aircraft spent in conflict.

Abstract: Operators with identical, demanding computer work (90 female and 97 male air traffic controllers) were found to have high prevalences of disorders (assessed by questionnaire and physical examination) in neck, shoulders and upper back. In spite of the identical work, the women displayed higher prevalences than the men (e.g. neck diagnoses 21% vs. 4%). Disorders in elbows, wrists and hands were less common, with similar rates in both genders. Generally, the psychosocial work environment (assessed by questionnaire) was found to be good, but with large inter-individual variation. Women experienced lower decision latitude than men, particularly regarding influence and freedom at work, but perceived higher social support. Physically, the work was characterized by relatively low angular velocities of upper arms (measured by inclinometry) and wrists (right: < 1 degrees/s during 19% of time, measuring by goniometry), dynamic muscular activities and high time fractions of rest in the trapezius and forearm extensor muscles (measuring by electromyography). There were only minor differences between the genders.

Abstract: Background noise is often discussed in terms of mental costs. In this study the effect of background noise on brain activity as reflected by the direct coupled (DC) potential was investigated by a within design in ten participants. During two successive blocks of 7 min each, participants performed 156 trials of a visual display terminal (VDT)-based visual-spatial attention task without noise and two blocks with a mixture of the environmental noises of barking dogs, traffic noise and irrelevant speech of 60 dBA. Brain DC potentials were recorded along the midline and analysed for change by time on task. For noise conditions, reaction time was prolonged and the DC-potential shifted towards positivity, contrary to control condition, independent of block and location. Results suggest reduced cortical resources by widespread inhibitory activation through background noise. It can be concluded that even low intensity background noise is associated with energy consumption and with impaired performance in spatial attention.

Abstract: In order to determine differences in biomechanical risk factors across different mouse positions within computer workstations a repeated measures laboratory study was completed with 30 adults (15 females 15 males). The subjects performed mouse-intensive tasks during two experiments. One experiment examined three mouse positions: a standard mouse (SM) position with the mouse directly to the right of the keyboard; a central mouse (CM) position with the mouse between the keyboard and the body, positioned in the body's mid-sagittal plane; a high mouse (HM) position, which simulated using a keyboard drawer with the mouse on the primary work surface. The second experiment compared two mouse positions: the SM position and a more central position using a keyboard without a number keypad (NM). Electrogoniometers and inclinometers measured wrist and upper arm postures and surface electromyography measured muscle activity of four forearm muscles and three shoulder muscles. The CM mouse position was found to produce the most neutral upper extremity posture across all measures. The HM position produced the least neutral posture and resulted in the highest level of muscle activity. Compared to the SM position, the NM position reduced wrist extension slightly and promoted a more neutral shoulder posture. Little difference in muscle activity was observed between the SM and NM positions. In conclusion, of these alternative mouse positions, the HM position was the least desirable, whereas the CM position reduced overall awkward postures associated with mouse-intensive computer tasks.

Abstract: We conducted a theoretical investigation of a complex command and control (C2) operation--the manoeuvres planning processes in Army land-battle situations, to improve understanding of how technology can best be designed to support planning and course of action development We drew upon results from cognitive task analyses and interviews with subject matter experts and insights gleaned from observations of Army training exercises and experiments to make inferences on the C2 activities carried out in preparation for tactical manoeuvres In this paper, we summarize several critical human factors issues associated with planning in a rapidly evolving environment, as identified in our investigation, and describe system design concepts aimed at addressing these challenges to distributed collaborative planning of C2 activities We conclude with implications for the application of these findings to other C2 domains

Abstract: The objective of this study was to define the quantitative relationship between external dynamic shoulder torques and calibrated perceived muscular effort levels for load delivery tasks, for application in job analyses. Subjects performed a series of loaded reaches and, following each exertion, rated their perceived shoulder muscular effort. Motion and task physical requirements data were processed with a biomechanical upper extremity model to calculate external dynamic shoulder torques. Calculated torque values were then statistically compared to reported calibrated perceived muscular effort scores. Individual subject torque profiles were significantly positively correlated with perceived effort scores (r2 = 0.45-0.77), with good population agreement (r2 = 0.50). The accuracy of the general regression model improved (r2 = 0.72) with inclusion of factors specific to task geometry and individual subjects. This suggests two major conclusions: 1) that the perception of muscular shoulder effort integrates several factors and this interplay should be considered when evaluating tasks for their impact on the shoulder region; 2) the torque/perception relationship may be usefully leveraged in job design and analysis.

Abstract: The two goals were to investigate, first, the practicability and reliability of observational assessment of team situation awareness (SA) and, second, the nature of any team differences, their consistency and training implications. Five shift teams tackled three scenarios, each with three probe events concerning SA, and three observers viewed and rated concurrently each shift. This methodology was found to be practicable and achieved satisfactory rater reliability as indicated by intraclass and inter-rater correlations. Team differences in SA emerged although there was no consistent pattern. A retrospective analysis of individual and team behaviours relating to SA was performed using the Critical Incident Technique. A total of 75 incidents and 20 behavioural dimensions relevant to SA were identified and these were subsumed under planning, problem solving, team coordination, attention, communication and knowledge. These findings are discussed with regard to the nature and measurement of SA, and the content of training to improve SA for control room teams.

Abstract: A field study was performed in a hospital pharmacy aimed at identifying positive and negative influences on the process of detection of and further recovery from initial errors or other failures, thus avoiding negative consequences. Confidential reports and follow-up interviews provided data on 31 near-miss incidents involving such recovery processes. Analysis revealed that organizational culture with regard to following procedures needed reinforcement, that some procedures could be improved, that building in extra checks was worthwhile and that supporting unplanned recovery was essential for problems not covered by procedures. Guidance is given on how performance in recovery could be measured. A case is made for supporting recovery as an addition to prevention-based safety methods.

Abstract: This study investigated failures of prospective memory (PM) as a relevant but neglected error type in medicine. A patient simulator was used to investigate PM failures. The influence of subjective ...

Abstract: The objective of this study was to determine if posture during gait can be affected by position of the load. It was hypothesized that the front pack would result in postural changes in the gait cycle, compared to a similarly loaded backpack. Thirteen healthy adults, free of any injury, volunteered to participate in this study. Two dimensional video data were collected at 50 Hz using a MacReflex video system. A backpack and a front pack were compared using loads of 10 and 15% of body weight. Markers were placed on the ear, acromion, greater trochanter and lateral joint line of the knee, lateral malleolus and fifth metatarsophalangeal joint. Data were collected while the participants walked at 0.75 stride/s. The data were used to calculate joint angles and displacements during each gait cycle. There was a significant difference noted in angles of the hip flexion, with the backpack condition demonstrating a greater flexion in each stride than either the control or front pack. Both backpack and front pack conditions demonstrated a significant change in neck motion compared to the control condition. The results of the position analysis over time also revealed an increase in the forward head position when participants were wearing the backpack compared to either the control or the front pack condition. It was concluded that the use of a front pack results in a more upright posture in gait, when compared to a backpack carrying the same load.

Abstract: There is an increasing prevalence for work to be analysed through naturalistic study, especially using ethnographically derived methods of enquiry and qualitative field research. The relatively unexplored domain of railway control (in comparison to signalling) in the UK is described in terms of features derived from observations and semi-structured interviews. In addition, task diagrams (a technique taken from the Applied Cognitive Task Analysis toolkit) are used to represent controllers' core elements of work, i.e. to manage events or incidents, and to identify the challenging steps in the process. The work features identified, the task diagrams, and the steps identified as challenging form a basis from which future ergonomics studies on railway controllers in the UK will be carried out.

Abstract: This study assessed several mechanical issues related to low back loading during pushing and/or pulling tasks. Nine male participants performed two-handed pushing and pulling tasks at two handle heights with three loads, using a cable pulley system. Four of these men were professional firefighters trained in performing pushing and pulling tasks while the other five were graduate students who lacked manual work experience. The more experienced firefighters produced less spinal compression and shearing forces when compared to the less experienced students under the same conditions. The firefighters were able to create less muscle activation as compared to the students, which indicated a more efficient technique. The main contributing factors to the forces produced on the low back were the quantity of the load being pushed or pulled, handle height, experience level and the technique of the participant. Thus, attempts to set load limits for pushing and pulling tasks are difficult, since technique has such a l...