Is whole-body vibration beneficial for seniors?

Normal aging processes result in losses of functional flexibility and muscular strength, which increase seniors’ fall risk and dependence on others. A relatively new intervention to reduce and/or reverse the adverse effects of aging is whole-body vibration (WBV) exercise. The purpose of this article is to review the established effects of WBV exercise exclusively with the aging population. A systematic search utilizing PubMed and Sport Discus databases uncovered journal articles specific to seniors and whole-body vibration. An extensive hand search supplemented the database results to find other relevant articles. Twenty-seven articles were obtained; all articles have been published in the past 8 years, reflecting the recent and growing interest in this area. Researchers have determined that WBV training can reduce fall risk and improve postural control in seniors. It has also been determined that WBV training can be as effective as conventional resistance training to improve seniors’ lower body strength. However, little is known about the effect of WBV exercise on flexibility and upper body strength in the aging population. More research is required to establish how effective WBV training is on these specific components and how it may affect seniors’ quality of life.     

Whole-body vibration training improves balance control and sit-to-stand performance among middle-aged and older adults: a pilot randomized controlled trial

Background

Aging is associated with decreased balance, which increases falling risk. The objective of the current study was to determine the feasibility and effects of whole-body vibration (WBV) training on knee extensor muscle power, limits of stability, and sit-to-stand performance among community-dwelling middle-aged and older adults in the United States.

Methods

A randomized pilot study with participant blinding was conducted. Feasibility outcomes included recruitment and compliance rate. Twenty-nine community-dwelling older adults were randomly assigned to perform body-weight exercises with either an individualized vibration frequency and amplitude, a fixed vibration frequency and amplitude, or no vibration. Isokinetic knee extensor power, limits of stability, and sit-to-stand tests were conducted before beginning the exercises (baseline) and after 8 weeks of training.

Results

With a favorable recruitment rate (58%) and compliance rates (attrition 9%; adherence 85%), the intervention was deemed feasible. The limits of stability endpoint excursion score for the individualized frequency–amplitude group was increased by 8.8 (12.9%; P = 0.025) after training, and that group’s maximum excursion score was increased by 9.2 (11.5%; P = 0.006) after training. The average weight transfer time score was significantly decreased by 0.2 s in the fixed group. The participants in the individualized group demonstrated a significant increase (3.2%) in weight rising index score after 8 weeks of WBV training.

Conclusions

WBV training is feasible for use with elderly people, and this study achieved good recruitment and compliance. The present paper suggests that 8 weeks of WBV training improves limits of stability and sit-to-stand performance. Future studies must determine whether WBV training improves other factors that affect posture control.

Trial registration

This study was registered at the Texas Woman’s University Institutional Review Board [TWU IRB 17632] on the 3rd of November 2014.

     

Reducing whole body vibration in forklift drivers

Forklift drivers in warehouses are often exposed to whole body vibration (WBV) during the total day. There is however an association between working as a forklift operator and the development of low back pain. In this study the exposure to WBV was measured in five forklift drivers who performed a standardised order picking task during 10 minutes. The effect of driving surface (uneven concrete vs. new flat concrete), driving speed (15 km/h vs. 8 km/h) and seat suspension (mechanical suspension vs. air suspension) was investigated. Improving the driving surface was the most effective preventive measure by reducing the whole body vibration with 39%, from 1.14 to 0.69 m/s2. Lowering the speed limit resulted in a reduction of WBV with 26% (1.05 vs. 0.78 m/s2). An air suspension seat was 22% more effective compared to mechanical suspension (1.02 vs. 0.80 m/s2). On uneven concrete an air suspension seat performed even better by reducing the WBV by 29% (1.33 vs. 0.95 m/s2). A combination of a new driving surface, limiting the maximum speed and the introduction of an air suspension seat reduced the whole body vibrations below the action limit of 0.5 m/s2 as mentioned in the European directive. None of the interventions were effective enough on their own.     

Impact of lightweight and conventional jackhammers on the operator

Jackhammer manufacturers have recently developed lightweight (45-60 lbs) jackhammers intended to reduce the required lifting and pushing forces during operation. However, the vibration characteristics of the lightweight jackhammers and their effect on muscle activity are currently unknown. The objective of this study was to compare the measured vibration and muscle activity between: (i) conventional (90 lb) and light weight (60 lb) jackhammers, (ii) different pavement type/thickness combinations, and (iii) pneumatic and hydraulic jackhammers. Five jackhammers were tested on 4 and 6 inch thick asphalt and concrete pavements by four experienced operators. Analysis of the results revealed that both weight classes averaged 9.7 m/s(2) at the 20 Hz weighted 1/3 octave band frequency, and the TLV of daily exposure for either weight class of jackhammer was less than 1.5 hours/per day. There was an approximately 33% difference in vibration measured on the hand of the operators due to pavement thickness, 30% due pavement type, and no difference due to power source. Conventional jackhammers overall produced higher muscle activity than lightweight jackhammers. Although selection of the correct jackhammer for the job involves many factors including pavement type and thickness, the results of this research can be used to assist in selecting the appropriate jackhammer.     

Exploring the Interaction Between Volunteering Status,Paid Job Characteristics and Quality of Volunteers’ Motivation on Mental Health

The literature on the health-promoting effects of community work has primarily dealt with the population in retirement age, yet the vast majority of volunteers are people still in the workforce. The aim of this study is to observe the relationship between volunteering and health within the context of working life, considering paid work conditions and motives to volunteer as moderating variables. We conducted an online survey with a sample of Swiss workers employed in different industries. Results show that volunteers with self-determined motives (but not with controlled motives) report lower levels of stress and burnout than non-volunteers. Moreover, volunteers in general (regardless of the quality of motivation) report higher levels of work engagement and well-being. Analyses further reveal an interaction effect for burnout and stress, where the difference between self-determined volunteers and non-volunteers becomes larger with unfavorable working conditions at their paid job, hinting at potential compensatory effects. Implications for future research and the voluntary sector are discussed.     

Arsenic exposure associated with decreased bone mineralization in male

Abstract

Objective: Arsenic (As) exposure may cause several medical problems. There were a few studies investigated whether it has affected bone tissue in women. However, there was no study in men. The aim of this study was to evaluate associations between bone mineral density (BMD) and As exposure in men subjects.

Material and methods: We enrolled in this study 254 subjects who due to chronic As exposure suspected and 82 subjects as a control group. Hair As levels were detected by a hair analysis (Varian AA240Z Zeeman Atomic Absorption Spectrometer, USA). BMD measurements were obtained using dual-energy X-ray absorptiometry instrumentation. We investigated associations between the hair As levels and BMD measurements.

Results: The frequency of osteoporosis and osteopenia was found to be 0.8% and 54.5%, respectively, in the As exposure group. The frequency of osteoporosis was found to be 1% and osteopenia was 32.4% in control subjects. There was significant difference between two groups (p?<?0.001). Hair As level has a median 1.01 (min: 0.06 and max: 25.71). There were no significant correlation between hair As levels and BMD measurements.

Conclusion: According to our observations, As exposure was associated with bone metabolism. Possible cause of osteopenia may be exposure to As. Further investigations are needed to estimate the relationship between As and bone metabolism.     

Social signals as design interventions for enhancing citizen science contributions*

Despite the scientific potential and increasing popularity of web-based citizen science, low contribution from volunteers is often a major hurdle. Studies have shown that individual behavior could be altered through targeted design interventions, but little is known about the specific factors that modulate volunteers’ contributions. A particularly elusive question entails the role of social feedback, in the form of targeted notifications about the contribution of other volunteers. Based on social comparison theory, we hypothesized that (1) volunteers increase contribution when presented with information about a high-performing peer or group, and (2) volunteers conform more strongly to a group rather than to a single peer. To test whether volunteers’ contributions change due to the exposure to the contribution of a peer or group norm, we systematically varied the information presented to participants in an environmental monitoring citizen science project. Volunteers increased their contributions when they were presented with the contribution of a high-performing peer and norm, but they were not influenced by a low-performing peer or norm. Further, we found that volunteers were more likely to match the contributions of a group than that of a peer. However, when volunteers were simultaneously exposed to information about a peer and a group, the effect depended on the respective performance of the peer and group. A theoretical model was developed to explain volunteers’ response and dissect the specific role of social comparison. Our findings offer the possibility of increasing volunteers’ contributions through design interventions.     

The effects of statistical fluctuations and perceived status of a competitor on the illusion of control in experienced gamblers

An experiment in gambling behavior was conducted under the most realistic conditions possible in our laboratory. Not only was there a significant monetary prize offered but subjects believed that they could be eliminated by a competitor. Subjects were 45 adults (25 females & 20 males; age range=23 to 73, mean age=51). Subjects were pitted in a gambling game against either a formidable or a vulnerable competitor. The competitor was a confederate playing one of the roles. The subjects either enjoyed a statistically favorable sequence of outcomes or suffered through a statistically negative sequence. In other words, they were made to lose badly, or made to win significantly. The object was to determine the effects of statistical fluctuations and the perceived status of a competitor on the illusion of control as measured by magnitude of risk taking. We hypothesized that we would see greater risks taken against a vulnerable competitor and during the favorable sequence, while lesser risks would be taken against a formidable competitor and an unfavorable sequence. However, neither variable was found to significantly effect the subjects on these measures. Unexpectedly, we identified a significant effect with respect to the number of wagers. It was found that subjects took significantly higher risks as a function of exposure to the gambling situation, without respect to conditions.     

Social Constructs and Human Service: Managerial Sensemaking of Volunteer Motivation

Managers of volunteers in human service interpret their job and experiences through a cognitive construct grounded in past interactions and experiences. This construct—sensemaking—then guides the managers' perceptions of subsequent interactions with peers, volunteers, and supervisors. Volunteers similarly make sense of their surroundings through cognitive constructions grounded in their own experiences. Unfortunately, managers and volunteers do not always make sense of their surroundings in the same way. Research has demonstrated that supervisors and paid employees may not necessarily agree in their perceptions of such issues as, for example, employee motivation. Such differences can lead to disagreements about the meaning of behaviors and the design of reward systems, eventually compromising organizational performance. In this study, sensemaking of volunteer motivation was assessed from the manager's perspective and compared with a previous study of volunteers themselves. Differences in understanding such a primary question as why volunteers are present can reasonably be expected to have an impact on organizational effectiveness. Interestingly, the predicted outcome of a different sensemaking schema was not supported in either the understanding of motivation or in the relative importance assigned to altruism. Additional attributes of volunteer managers were also considered to determine if sensemaking is driven by environmental factors such as exposure to volunteers, tenure as a volunteer manager, or social roles associated with gender constructs. These additional attributes were not found to significantly affect the process of attribution of altruistic motives.     

Heterogeneity of Loss Aversion in Pathological Gambling

Pathological gambling (PG) is characterized by continual repeated gambling behavior despite negative consequences. PG is considered to be a disorder of altered decision-making under risk, and behavioral economics tools were utilized by studies on decision-making under risk. At the same time, PG was suggested to be a heterogeneous disorder in terms of personality traits as well as risk attitude. We aimed to examine the heterogeneity of PG in terms of loss aversion, which means that a loss is subjectively felt to be larger than the same amount of gain. Thirty-one male PG subjects and 26 male healthy control (HC) subjects underwent a behavioral economics task for estimation of loss aversion and personality traits assessment. Although loss aversion in PG subjects was not significantly different from that in HC subjects, distributions of loss aversion differed between PG and HC subjects. HC subjects were uniformly classified into three levels (low, middle, high) of loss aversion, whereas PG subjects were mostly classified into the two extremes, and few PG subjects were classified into the middle range. PG subjects with low and high loss aversion showed a significant difference in anxiety, excitement-seeking and craving intensity. Our study suggested that PG was a heterogeneous disorder in terms of loss aversion. This result might be useful for understanding cognitive and neurobiological mechanisms and the establishment of treatment strategies for PG.     

青年志愿者的需要特征与激励对策

青年志愿者作为志愿服务队伍的主体部分,其需要能否得到有效满足直接关系到志愿组织队伍的整体稳定和志愿服务活动的持续性发展。目前,青年志愿者的需要状况整体呈现较低层次的生存性需要与较高层次的发展性需要的两极分化特征。追求理解尊重是全体志愿者的首位需要;青年志愿者较中老年志愿者、高学历志愿者较低学历志愿者、高经济收入志愿者较低经济收入志愿者有着更强烈的发展性需要。应针对青年志愿者不同的需要,采取差别性的激励措施。     

Could mild hypoxia impair pilot decision making in emergencies?

The decreased pressure in the cabin of a pressurised aircraft (typically equivalent to ~8000 ft) reduces the oxygen level so that the blood oxygen saturation of all occupants falls from >97% (normoxia) at sea-level to below 92% (mild hypoxia). Although exposure to mild hypoxia does not affect well-learned cognitive and motor performance of aircrew, it has been proposed that it can affect the performance of some complex cognitive performance tasks involving multiple demands typical of emergency tasks that may have to be performed by pilots. In order to simulate some of these complex cognitive demands, 25 student volunteers participated in an experiment which assessed performance of complex logical reasoning and and multiple memory tasks before and after 2 hours of exposure to normoxia and mild hypoxia. Performance for the more difficult components of the complex reasoning task, especially involving conflict decisions, were marginally significantly degraded by mild hypoxia. Since the effects were only marginally significant future studies should investigate the effects of mild hypoxia on more subtle complex decision-making tasks.     

Lead exposure is a risk for worsening bone mineral density in middle-aged male workers

Abstract

Objective: Lead exposure linked to osteoporosis in women. However, there is no direct evidence whether lead exposure has effects on bone metabolism in middle-aged male subjects. Therefore, the present study investigated the relationship between bone mineral densitometry measurements, bone markers, endocrine hormones and blood lead levels.

Material and methods: The present study included lead exposure patients (n: 30) and control subjects (n: 32). We recorded information on patient demographics and risk factors of osteoporosis. Blood lead levels were evaluated using Varian AA 240Z atomic absorption spectrophotometry. Bone mineral density measurements were measured using dual-energy X-ray absorptiometry.

Results: Each lumbar T and Z scores in the lead exposure group were lower than the control group. There were no significant differences in femur neck and femur total T and Z scores between two groups. Blood lead levels were also negatively correlated with lumbar 2-4 T score, total lumbar T score, lumbar 2-4 Z score and total lumbar Z score. Urinary hydroxyproline and urinary deoxypyridinoline levels in the lead exposure group were significantly higher compared to controls. Blood lead levels were strong, positively correlated with urinary deoxypyridinoline. Endocrine hormone levels and 1,25-dihydroxy-vitamin D3 levels were comparable between lead exposure and control group.

Conclusion: Lead exposure in male workers is an important factor for deterioration in bone mineral density. We should be screening blood lead levels and history of lead exposure in male osteoporosis.     

Emotional Empathy as Related to Mimicry Reactions at Different Levels of Information Processing

The hypotheses of this investigation were based on conceiving of facial mimicry reactions in face-to-face interactions as an early automatic component in the process of emotional empathy. Differences between individuals high and low in emotional empathy were investigated. The parameters compared were facial mimicry reactions, as represented by electromyographic (EMG) activity, when individuals were exposed to pictures of angry or happy faces. The present study distinguished between spontaneous facial reactions and facial expressions associated with more controlled or modulated emotions at different information processing levels, first at a preattentive level and then consecutively at more consciously controlled levels: 61 participants were exposed to pictures at three different exposure times (17, 56, and 2350 ms). A significant difference in facial mimicry reactions between high- and low-empathy participants emerged at short exposure times (56 ms), representing automatic, spontaneous reactions, with high-empathy participants showing a significant mimicking reaction. The low-empathy participants did not display mimicking at any exposure time. On the contrary, the low-empathy participants showed, in response to angry faces, a tendency to an elevated activation in the cheek region, which often is associated with smiling.     

PAYOFF DOMINANCE VS. COGNITIVE TRANSPARENCY IN DECISION MAKING

This paper reports on three laboratory experiments designed to investigate the roles of decision costs and rewards on the accuracy of economic decisions. The experimental vehicle is a purchase decision employing the Becker-DeGroot-Marshak (BDM) mechanism. The first experiment verifies the incentive-compatibility of the BDM in a pure induced-value setting; the second tests its performance under different information regimes and payoff schedules; the third addresses the role of feedback information. Steep payoff schedules are found to be necessary to optimizing behavior only in cases where subjects must search out an optimal strategy rather than being able to deduce it from information provided. (JEL C91, D83)     

Physical aggression after being crowded

Subjects were given an opportunity to aggress using a Buss machine either immediately or 30 minutes after competing or cooperating on a task in a crowded or uncrowded situation. It was found that for subjects who were allowed to aggress immediately, crowding reduced aggression under the competitive set but had no effect under the cooperative set. This effect of crowding was not found with the delay subjects. The results of this study are consistent with the findings of other studies that social withdrawal rather than aggression may occur in response to aversively dense conditions. The lack of crowding effect after a 30-minute delay suggests that the effect of the laboratory crowding experience is transient in nature and best generalized to short-term crowding experiences such as those encountered on elevators and buses.     

Gender differences in mental health consequences of exposure to political violence among Israeli adolescents

This study examined the role played by gender differences in the relation between political violence exposure and mental health during adolescence. Understanding these differences is particularly pertinent during the period of adolescence characterized as it is by processes of identity formation and gender role consolidation. Participants were 154 high school students recruited from two high schools in central Israel (78 males, 76 females; average age 16.54), who completed the Political Life Events Scale for measurement of political violence exposure, the Brief Symptom Inventory-18 for assessment of psychological symptoms and disorders, a risk-taking behavior scale, and the Posttraumatic Stress Symptom Scale — Interview (PSS-I) for assessment of posttraumatic stress symptoms. Results reflected high levels on many psychological indicators. The dose–response hypothesis was partially confirmed with adolescents' higher reported political violence exposure related only to higher levels of somatization and greater severity of posttraumatic stress symptoms. Contrary to the literature, only a few gender differences emerged and these showed mixed patterns. Females showed higher levels of anxiety than males, and males showed higher levels of risk-taking behavior. Females exposed to low political violence exposure showed significantly less substance abuse than males but those with high exposure reported significantly higher levels of substance abuse, equivalent to those of males. Findings show a complex constellation of gender effects on relations between political violence exposure and different psychopathological outcomes. Findings of this study indicate the necessity for more refined examination of gender differences in psychological processes in reaction to living in conditions of protracted conflict and war.     

The effects of specific versus nonspecific reinforcement on verbal behavior

The current study is a systematic replication and extension of previous research on the differences between specific (mand) and nonspecific (tact) reinforcement. The focus was on the role that these different consequences played in the acquisition of verbal behavior. Using both a within-subject and a between-subjects design, the current researchers trained eight essentially nonverbal individuals to tact a variety of foods under two different reinforcement conditions. The results showed no significant differences between the four matched-pairs in rates of acquisition, or in the resistance to extinction. However, subjects in the specific reinforcement condition emitted more untrained mand-compliance responses, while subjects in the nonspecific group demonstrated increased generalization to multiply controlled mand conditions. The results supported previous findings which indicated that the two types of consequences were equally effective in the acquisition of tacting, but each had unique features and implications for language training with nonverbal populations.

     

The aging male in African ethnic cultures

Objective.?To test the relationship between gonadal status and objective measures and determinants of physical performance in older men and their determinants.

Methods.?The study included 455?≥?65 year older men of InCHIANTI study, Italy, with complete data on testosterone levels, hand grip strength, cross-sectional muscle area (CSMA), short physical performance battery (SPPB). Linear models were used to test the relationship between gonadal status and determinants of physical performance.

Results.?Three different groups of older men were created: (1) severely hypogonadal (N?=?23), total testosterone levels ≤230?ng /dl; (2) moderately hypogonadal (N?=?88), total testosterone >230 and?N?=?344), testosterone levels ≥350?ng/dl. With increased severity of hypogonadal status, participants were significantly older while their BMI was substantially similar. In the age and BMI adjusted analysis, there was a significant difference in haemoglobin levels, hand grip strength and SPPB score (p for trend?p for trend?=?0.004) and haemoglobin (p for trend?Conclusions.?In older men, gonadal status is independently associated with some determinants (haemoglobin and muscle strength) of physical performance.