Changes in human cervical and lumbar spine curves while bicycling with different handlebar heights

Cycling is a daily activity that needs a high demand of human-bicycle fitness. However, studies into the fitness or ergonomic aspects are very little. In this study, the simulated 20 min bicycling test were performed by 26 male participants under 5 handle height conditions. Body joint angles and external cervical/lumbar spine lordosis were measured at the initial and cycling after 20 min. Results show that different handle heights did cause various trunk inclinations. Trunk inclination was negatively and positively correlated with lumbosacral angle (r = -0.620, p < 0.001) and cervical angle (r = 0.510, p < 0.001), respectively. In this study, regression models were also developed to predict the internal cervical and lumbar spine movements by external trunk inclination and head extension, respectively. The explanatory abilities for the variance of the models were 67.2% for LSA and 82.8% for CE prediction. This can be used to understand the cyclist's spine movements while field study of bicycling.     

A collaborative effort to apply ergonomics to electric utility workers at generating stations

As part of a collaborative approach involving electric utility companies, university researchers, individual contractors and a not-for-profit research institute, two ergonomics teams consisting of skilled utility workers and trained ergonomists, were assembled. These teams were to identify tasks with risk factors for musculoskeletal disorders (MSDs) among workers in fossil-fueled generating stations and and to propose ergonomic interventions for these tasks. One team focused on tasks of electricians and the other focused on tasks of plant operators and mechanics. Several of the tasks were tested in an ergonomics laboratory and at one of the utility's generating stations. We present a sample of the recommended interventions in this paper. An anthropometric analysis of electrical box height recommended the appropriate height for electrical boxes. The results of a field experiment showed that low rolling resistance wheels decreased the forces to initiate and sustain pushing a cart. The same experiment also demonstrated that the forces required to turn a cart with six wheels were lower than the forces equired to turn a cart with four wheels. A collaborative approach to ergonomics proved to be an effective method to identify and assess tasks that are problematic for workers and to develop best practices for these tasks in the electric power industry. This method could be used by other industries in their attempt to decrease the incidence, cost and severity of workplace MSDs.     

Child Abuse and Sudden Infant Death

In times past, parents were usually blamed when an infant died suddenly and unexpectedly. A more caring attitude evolved with the adoption of the term ‘cot death’ or ‘sudden infant death syndrome’ (SIDS). Recent research looking at the factors responsible for SIDS has focused on aspects of child care and parental behaviour. Epidemiological studies confirm that several risk factors associated with child maltreatment are also to be found in many families who experience a sudden infant death. Social deprivation and other well-known associated features linked to maltreatment are correlated with sudden death in infancy. It is suggested that both physical abuse (suffocation is the most usual mechanism proposed) and neglect (failure to thrive, failure to recognize and treat illness) are important mechanisms. Infanticide (filicide) has existed widely over past centuries and its continuation in modern times is reflected in the highest murder rates of all age groups in infancy. However, much fatal abuse and neglect remains hidden, as demonstrated from the results of detailed fatality reviews. The evidence linking child abuse and neglect with sudden unexpected death in infancy is reviewed.     

Analysis of the compensatory postures adopted by day caregivers through OWAS-Ovako Working Posture Analysing System

The Ergonomic Work Analysis reports that there are many activities performed by the professional caregivers and that they are exposed to physical and psychological overload. This situation favors the emergence of pain which influences the quality of life in the work place. In this way, the objective of this study was to verify the main postural constraints adopted by caregivers in public day cares. Visits were conducted in 28 day cares aiming at performing an interview to 126 caregivers who have been working for more than 4 years. From the questionnaire it was found that 80% of the participants refer some sort of pain, being 42% in the trunk, 33% in the shoulder and 25% in the lower limbs. The data from OWAS method showed that from the total of 30 postures performed during the work One could see that the main postures adopted by the caregivers were: flexion, lateral inclination and rotation of the trunk and most of the time they are standing. These movements, when bad performed, can lead to injuries in the lower limbs, upper limbs and trunk. It's necessary more attention to these workers.Thought preventive ergonomic actions to reduce pain symptoms and promote a work in health and safety.     

Kinematic analysis of post office employees' workstations

This study analyzed a post office clerk's tasks, comparing two workstation models. The clerk was facing the client in one, and seated at 45 degrees to the counter in the other. We analyzed the most frequent tasks and those presenting the most critical points: 1) payment of a postal order; 2) accepting a registered letter, breaking them down into subtasks. We used an optoelectronic system for kinematic analysis, and calculated the range of motion of the trunk and arms in the three spatial planes. The 45( position required less torsion of the trunk and head when using the printer, placed to the left of the employee. A larger worktop improved the workstation, leaving more room for equipment and allowing the worker to sit frontally to the monitor. However, this solution involved a shorter distance between the worker and the client with longer extension of the shoulder and elbow and less trunk flexion. These findings suggested a modification in the layout that shortens the distance between the worker and client.     

Biomechanical analysis of loading/unloading a ladder on a truck

Loading/unloading a ladder on vehicles are frequent tasks and involve overhead handling that may expose workers to risk factors of shoulder musculoskeletal disorders. The objective of the present study was to evaluate posture, forces required and perceived exertion when loading and unloading the ladder on a utility truck. Thirteen male overhead line workers from an electric utility in Brazil participated in this study. Shoulder elevation angle was measured using inclinometers. The required force to load/unload the ladder was measured by dynamometer. Subjective assessment of the perceived exertion was recorded to compare the exertion reported during the test conditions to the field conditions. The task of loading/unloading the ladder presented risks of shoulder musculoskeletal disorders (MSDs) to workers because it requires high levels of force (approximately 60% of the maximal force) combined with overhead posture of the shoulders (more than 100° from the neutral posture). Age and height presented to interfere in biomechanical risks presented in load/unload task. There was no significant difference between the subjective exertion during the test conditions and handling the ladder in the field. Ergonomic intervention is recommended to reduce these risks for shoulder MSDs.     

A systematic review of gait perturbation paradigms for improving reactive stepping responses and falls risk among healthy older adults

Background

Falls are a leading cause of injury among older adults and most often occur during walking. While strength and balance training moderately improve falls risk, training reactive recovery responses following sudden perturbations during walking may be more task-specific for falls prevention. The aim of this review was to determine the variety, characteristics and effectiveness of gait perturbation paradigms that have been used for improving reactive recovery responses during walking and reducing falls among healthy older adults.

Methods

A systematic search was conducted in PubMed, Web of Science, MEDLINE and CINAHL databases in December 2015, repeated in May 2016, using sets of terms relating to gait, perturbations, adaptation and training, and ageing. Inclusion criteria: studies were conducted with healthy participants of 60 years or older; repeated, unpredictable, mechanical perturbations were applied during walking; and reactive recovery responses to gait perturbations or the incidence of laboratory or daily life falls were recorded. Results were narratively synthesised. The risk of bias for each study (PEDro Scale) and the levels of evidence for each perturbation type were determined.

Results

In the nine studies that met the inclusion criteria, moveable floor platforms, ground surface compliance changes, or treadmill belt accelerations or decelerations were used to perturb the gait of older adults. Eight studies used a single session of perturbations, with two studies using multiple sessions. Eight of the studies reported improvement in the reactive recovery response to the perturbations. Four studies reported a reduction in the percentage of laboratory falls from the pre- to post-perturbation experience measurement and two studies reported a reduction in daily life falls. As well as the range of perturbation types, the magnitude and frequency of the perturbations varied between the studies.

Conclusions

To date, a range of perturbation paradigms have been used successfully to perturb older adults’ gait and stimulate reactive response adaptations. Variation also exists in the number and magnitudes of applied perturbations. Future research should examine the effects of perturbation type, magnitude and number on the extent and retention of the reactive recovery response adaptations, as well as on falls, over longer time periods among older adults.

     

Stationarity test of electromyographic signals during isokinetic trunk exertions

The aim of this study is to investigate the stationarity of the electromyographic (EMG) signals during isokinetic exertions of the trunk muscle. Six healthy subjects participated in this study. The erector spinae muscles were used to collect the signals. In order to simulate the isokinetic exercises of the trunk, a Cybex system with a trunk modular component was used. All subjects performed sustained exertions with a combination of load (25%, 50% MVC) and angular velocity (0, 15, 30 degree/s). The stationarity of the signals was tested by the reverse arrangements test and modified reverse arrangements test. In the results, the signal stationarity was high in all conditions in the reverse arrangements test. However, in the modified reverse arrangements test it was relatively low at about the 30 degree/s angular velocity. In the analysis of variance, the effect of angular velocity was statistically significant at the 0.05 significance level in the modified reverse arrangements test and Tukey's HSD grouping showed that the stationarity of 30 degree/s angular velocity was significantly different from 0, 15 degree/s condition. These results indicate that the stationarity of the EMG signals showed no difference between isometric and isokinetic conditions when the angular velocity was equal to 15 degree/s.     

A field experiment comparing mechanical demands of two pruners for flower cutting

Manual flower cutting requires repetitive forceful movements that may explain the high incidence of upper-extremity MSDs among workers of the Colombian flower industry. Force demands may be caused by the use of pruners that have not been designed for Colombian workers. We conducted a repeated measures field experimental study (n=16, 69% women, 20 to 60 years old) to compare the mechanical demands during rose cutting of two different pruners (Traditional vs. alternative pruner) at two different cutting heights (elbow vs. over-shoulder). Demands included the perceived comfort, perceived effort and upper limb's muscular activity and posture. Workers perceived their traditional pruner as more comfortable but requiring more effort than the prototype tool. No benefits were observed regarding ulnar deviation with the alternative pruner. The wrist extension and related muscular activity of the wrist extensors were higher with the prototype pruner. The prototype pruner resulted in reduced muscular load of the wrist flexors; the biceps when working at the elbow height; and the deltoids when working at the shoulder height. However, Moderate results may be explained by the lack of time for workers' adaptation to the alternative tool. New design developments must focus on reducing extension and ulnar deviation of the wrist.     

Biomechanics of the heel-raise exercise

The purpose of this investigation was to determine whether increases in internal (muscular) demand would be proportional to increases in the external demand during heel-raise exercise. Seven male (mean age 74.9 +/- 4.8 years) and 9 female (mean age 74.4 +/- 5.1 years) older adults performed both double-leg heel raises and single-leg heel raises under 3 loading conditions (no external resistance and +5% and +10% of each participant's body weight). Kinematic and kinetic dependent variables were calculated using standard inverse-dynamics techniques. The results suggest that although the single-heel raise led to increases in peak net joint moments, power, and mechanical-energy expenditure (MEE), it did so at the expense of range of motion and angular velocity. In addition, increasing the external resistance by 5% of participants' body weight did not elicit significant changes in either the power or the MEE of the ankle joint. These effects should be considered when prescribing these exercises to older adults.     

Modernity’s dirt: carbon emissions and the technique of life

ABSTRACT

Under colonialism, the concept of dirt was frequently employed ideologically to make judgements about relative worth. In Africa, a particular European cultural idiom or “technique of life” was presented as superior because of its “cleanliness.” This paper is concerned with modernity’s “technique of life” at a particular historical moment when, as a result of environmental crisis, it is suddenly called upon to give an account of itself. I undercut modernity’s claim to cleanliness by suggesting that what it introduces alongside regimes of order and sanitation is a much more globally destructive form of dirt in the form of increasing carbon dioxide levels. The CAIT Climate Data Explorer is a website that compares carbon dioxide emissions across a range of categories. This paper reads three graphs generated by this website as incomplete figures for making visible modernity’s “technique of life.” Realist fiction, read as a supplement to the climate graph records, is able to reinvest some of the abstract categories employed by the climate data tool – transport, fugitive emissions and electricity use – with the details that characterise particular techniques of life and to reveal the way they continue to be defined, at this historical moment, by narratives of development and consumption.     

Human motion behavior while interacting with an industrial robot

Human workers and industrial robots both have specific strengths within industrial production. Advantageously they complement each other perfectly, which leads to the development of human-robot interaction (HRI) applications. Bringing humans and robots together in the same workspace may lead to potential collisions. The avoidance of such is a central safety requirement. It can be realized with sundry sensor systems, all of them decelerating the robot when the distance to the human decreases alarmingly and applying the emergency stop, when the distance becomes too small. As a consequence, the efficiency of the overall systems suffers, because the robot has high idle times. Optimized path planning algorithms have to be developed to avoid that. The following study investigates human motion behavior in the proximity of an industrial robot. Three different kinds of encounters between the two entities under three robot speed levels are prompted. A motion tracking system is used to capture the motions. Results show, that humans keep an average distance of about 0,5m to the robot, when the encounter occurs. Approximation of the workbenches is influenced by the robot in ten of 15 cases. Furthermore, an increase of participants' walking velocity with higher robot velocities is observed.     

Validity of the microsoft kinect system in assessment of compensatory stepping behavior during standing and treadmill walking

Background

Rapid compensatory stepping plays an important role in preventing falls when balance is lost; however, these responses cannot be accurately quantified in the clinic. The Microsoft Kinect? system provides real-time anatomical landmark position data in three dimensions (3D), which may bridge this gap.

Methods

Compensatory stepping reactions were evoked in 8 young adults by a sudden platform horizontal motion on which the subject stood or walked on a treadmill. The movements were recorded with both a 3D-APAS motion capture and Microsoft Kinect? systems. The outcome measures consisted of compensatory step times (milliseconds) and length (centimeters). The average values of two standing and walking trials for Microsoft Kinect? and the 3D-APAS systems were compared using t-test, Pearson’s correlation, Altman-bland plots, and the average difference of root mean square error (RMSE) of joint position.

Results

The Microsoft Kinect? had high correlations for the compensatory step times (r?=?0.75–0.78, p?=?0.04) during standing and moderate correlations for walking (r?=?0.53–0.63, p?=?0.05). The step length, however had a very high correlations for both standing and walking (r?>?0.97, p?=?0.01). The RMSE showed acceptable differences during the perturbation trials with smallest relative error in anterior-posterior direction (2-3%) and the highest in the vertical direction (11–13%). No systematic bias were evident in the Bland and Altman graphs.

Conclusions

The Microsoft Kinect? system provides comparable data to a video-based 3D motion analysis system when assessing step length and less accurate but still clinically acceptable for step times during balance recovery when balance is lost and fall is initiated.

     

The effects of back belts and load on selected lifting kinematics during a simulated patient transfer

This study used two dimensional biomechanical analysis to examine the effects of back belts and lifting load on selected lifting kinematics during a simulated patient transfer. A human manikin placed in a sitting position was attached to a customized lifting apparatus which controlled the lifting load and direction of the manikin. Eighteen female participants, between the age of 21 and 27, completed six lifts (sit to stand transfers) of the manikin. Three lifts were completed at the 30 lb load condition (no belt, belt 1 and belt 2) and three lifts were completed at the 50 lb load condition (no belt, belt 1 and belt 2). A doubly two way ANOVA found a significant main effect for the belt condition, F(12,6)=10.06, P=0.002. There was no significant effect for load and no interaction existed between belt and load. The results revealed a significant decrease in trunk flexion when participants wore the wider (nine inch) belt during the 30~lb lifts when compared to the no belt trials. No significant differences were found in trunk flexion means with the narrower width (six inch) belt. No significant differences were found in trunk spinal flexion with either belt condition during the 50 lb lifts. There were no significant differences found in either of the belts in the means of lifting time, knee flexion, elbow flexion, forward displacement of the lifter's center of mass, and the lifter's maximum center of mass velocity. The results suggest that wider back belts may be more effective at reducing spinal flexion during patient lifting under moderate load conditions when compared to narrower back belts and to no-belted controls.     

Nursing home administrators' views of volunteers' work in an ombudsman program

This research investigated nursing home administrators' (NHAs) perceptions of visits of volunteers in an ombudsman program in relation to effectiveness and satisfaction. Unlike placements of other volunteers made at the behest of organizations, visits of volunteer advocates, which may be mandated and include evaluative assessments of care, usually do not occur at the invitation of NHAs. Yet, outcomes for administrators are not often studied. Despite research showing stress attributed to interaction with state agencies, questionnaire data from 196 NHAs indicated that more contact between volunteers and NHAs was associated with perceptions of greater effectiveness and satisfaction. Those who found visits infrequent and with little impact rated the work of volunteers as less effective and were less satisfied. Qualitative data describe unexpected benefits of visits that were internal and external to the facilities.     

Capturing temporal dynamics of fear behaviors on a moment‐to‐moment basis

Identifying patterns of fearful behaviors early and accurately is essential to identify children who may be at increased risk for psychopathology. Previous work focused on the total amount of fear by using composites across time. However, considering the temporal dynamics of fear expression might offer novel insights into the identification of children at risk. One hundred and twenty‐five toddlers participated in high‐ and low‐fear tasks. Data were modeled using a novel two‐step approach. First, a hidden Markov model estimated latent fear states and transitions across states over time. Results revealed children's behavior was best represented by six behavioral states. Next, these states were analyzed using sequence clustering to identify groups of children with similar dynamic trajectories through the states. A four‐cluster solution found groups of children varied in fear response and regulation process: “external regulators” (using the caregiver as a regulation tool), “low reactive” (low reaction to stimulus), “fearful explorers” (managing their own internal state with minimal assistance from the caregiver), and “high fear” (fearful/at‐caregiver state regardless of task). The combination of analytic tools enabled fine‐grained examination of the processes of fearful temperament. These insights may help prevention programs target behaviors that perpetuate anxious behavior in the moment.     

And,the Winner Is…A Visual Preference for Endpoints over Starting Points in Infants’ Motion Event Representations

Infants represent objects that are endpoints in motion events and show a preference for encoding the endpoint (the duck waddles into a bowl) over the starting point (the duck waddles out of a box). This asymmetry continues to appear in nonlinguistic cognition and language throughout development. This study tests whether this asymmetry also shows up in 16‐month‐old infants’ visual preferences for motion events, and if so, for which types of events. Infants looked longer at events depicting an “agentive” figure (e.g., duck) moving into an object (endpoint) than out of an object (starting point), and this asymmetry persisted even when the starting point object was larger and more colorful than the endpoint object and when it caused the motion of the figure. However, an asymmetry was not found when motion into/out of the endpoint/starting point involved was performed by a “nonagentive” (e.g., leaf) figure. These findings suggest that an endpoint/starting point asymmetry in infant cognition (1) extends to infants’ visual preferences of motion events, (2) shows up most strongly for events that involve an “agentive” figure, and (3) is largely unaffected by the physical saliency of the starting point object. How a visual endpoint preference may support the acquisition of spatial language is considered.     

Arranged Marriages as Support for Intra‐ethnic Matchmaking? A Case Study on Muslim Migrants in Germany

This article discusses the behavioural and institutional mechanisms that guide the matchmaking process of arranged marriages 1 amongst Muslim migrants in Germany and clarifies how this practice may influence ethnic homogamy. The focus is on general characteristics of arranged marriages rather than differences between diverse ethnic groups. The methodology is qualitative due to the sensitive and complex topic and the current state of research. Typically, the whole family is deeply involved in the process of arrangement, which consists of three stages (pre‐engagement, engagement, marriage). Thereby, the extension of parental scope of action by means of institutionalized admission procedures turns out to be vitally important. In consideration of the fact that mate selection takes place at the pre‐engagement stage, it is the most crucial. Furthermore, differences to other partner‐choosing processes are at their most distinct at this point, being responsible for the identification and labelling of this model as an arranged marriage. Selection criteria are mainly determined by the reputation of the marriage candidate and her/his family along with cultural features (such as belonging to a particular religious group, ethnicity or nationality). In our study, preferences for a cultural homogenous match were the most dominant ones. This inclination may cause the tendency towards transnational marriages when there are no suitable marriage candidates to be found in Germany.     

On Parallel Process in Social Work Supervision

The recognition and study of parallel process in social work supervision offers both the social work supervisor and supervisee a rich learning opportunity at the moment when an impasse seems unworkable. The parallel process is an unconscious replication in the supervisory session of therapeutic difficulties which a supervisee has with a client. This replication may originate with the supervisor unwittingly modeling behavior that is then taken by the social worker into the therapeutic interaction with the client. This paper reviews the need for social workers to grasp the dynamics of the parallel process, discusses the literature for the historical development of the phenomenon, addresses supervisory methods that will uncover the process, and illustrates the supervisor's stages of exploration and modeling in addressing the parallel process.     

Trajectory Discrimination and Peripersonal Space Perception in Newborns

The ability to discriminate the trajectories of moving objects is highly adaptive and fundamental for physical and social interactions. Therefore, we could reasonably expect sensitivity to different trajectories already at birth, as a precursor of later communicative and defensive abilities. To investigate this possibility, we measured newborns' looking behavior to evaluate their ability to discriminate between visual stimuli depicting motion along different trajectories happening within the space surrounding their body. Differently from previous studies, we did not take into account defensive reactions, which may not be elicited by impending collision as newborns might not categorize approaching stimuli as possible dangers. In two experiments, we showed that newborns display a spontaneous visual preference for trajectories directed toward their body. We found this visual preference when visual stimuli depicted motion in opposite directions (approaching vs. receding) as well as when they both moved toward the peripersonal space and differed only in their specific target (i.e., the body vs. the space around it). These findings suggest that at birth human infants seem to be already equipped with visual mechanisms predisposing them to perceive their presence in the environment and to adaptively focus their attention on the peripersonal space and their bodily self.