Practical Aspects of Synovial Fluid Aspiration: The Approaches to Major Extremity Joints and Examination of the Aspirate

Use of a few simple office laboratory procedures can provide accurate diagnosis of several forms of common diseases of joints. The average physician can discover unsuspected joint disease in this way, thereby avoiding expensive laboratory tests and delay in making the diagnosis. An adequate history and physical examination are needed in conjunction with analysis of fluid aspirated from the joint.     

Aerobic capacity of forestry workers and physical demands of forestry operations.

The present study aimed at evaluating the aerobic capacities of forestry workers and the physical demands of their occupation. A submaximal cycle ergometer test was conducted on 22 male forestry workers and 15 male sedentary office workers aged 40-59 years. The slope of the regression line of heart rates on given exercise intensities was significantly smaller in the forestry workers than in the office workers. The mean heart rate of the forestry workers was 9 beats.min-1 less than that of the office workers at the initial exercise intensity of 50 W. This difference increased to 25 beats.min-1 at 175 W. For 6 of the 22 forestry workers, heart rates were recorded continuously during a usual workday. The metabolic rates, as multiples of basal metabolic rate (in met) of various forestry activities were estimated from the average heart rate during the activity of interest and a predicted maximal oxygen consumption of the subject obtained from a submaximal cycle ergometer test. The mean energy expenditure was 4.5 met with a range of 3.3-6.3 met for an average of 509 min at a worksite. These results indicated that the forestry workers had high aerobic capacities and this was ascribed to the high physical demands of their occupation.     

Evaluation of the kinematic parameters of normal-paced gait in subjects with gonarthrosis and the influence of gonarthrosis on the function of the ankle joint and hip joint

The aim of the study was to assess the variability of parameters characterising the gait of persons suffering from degenerative changes of the knee joint and their influence on the ankle and hip joints. The values of the angular changes in the knee, ankle and hip joints in the three planes of motion were assessed. Locomotion tests were performed on 27 persons, aged between 60 and 74, using Vicon 250, the three-dimensional analysis system. The sharpest deviations from the results of the control group were revealed in the transverse and frontal planes. Degenerative knee joint disease has changed the gait stereotype causing a reduction in the economy of gonarthrosis patients' locomotion, the influence of the disease on the function of the neighbouring joints is also distinctly marked.     

The sociality of the wage: money rhythms,wealth circulation,and the problem with cash on the Zimbabwean‐South African border

While wage labour and money have received much anthropological attention, the same cannot be said of wages themselves – actual banknotes and coins distributed in workforces. This article traces wages' social productivity among farm workers on the Zimbabwean‐South African border. In this migrant‐labour setting, money's form matters. Because currency objects are physically the same, it is difficult for workers to store them in an insecure environment, leading them to turn to one another. As they manage their earnings, workers attempt to establish themselves as social persons while maintaining future options in uncertain circumstances. Workforce ties both shape and are constituted by flows of cash and the rhythms and circuits of the wage. Seen in terms of form, wages are highly personal – the very stuff of sociality.     

Indoor Tracking to Understand Physical Activity and Sedentary Behaviour: Exploratory Study in UK Office Buildings

Little is known of the patterns of physical activity, standing and sitting by office workers. However, insight into these behaviours is of growing interest, notably in regard to public health priorities to reduce non-communicable disease risk factors associated with high levels of sitting time and low levels of physical activity. With the advent and increasing availability of indoor tracking systems it is now becoming possible to build detailed pictures of the usage of indoor spaces. This paper reports initial results of indoor tracking used in conjunction with the ActivPAL activity monitoring device. In this paper we give an overview of the usage of the tracking system and its installation and illustrate some of the resultant data. We also provide preliminary results that investigate the relationship between location, light physical activity and sitting in a small sample of office workers (n=33) from two separate office environments in order to demonstrate the relevance and explanatory power of the technique.     

EMG median frequency changes in the neck–shoulder stabilizers of symptomatic office workers when challenged by different physical stressors

The problem of work-related neck and upper limb disorders among computer users has been reported extensively in the literature, and commonly cited risk factors include static posture, speed and force of keyboard operation. The present study examined changes in median frequency (MF) of the neck–shoulder muscles in symptomatic and asymptomatic office workers when they were exposed to these three physical stressors.

A quasi-experimental Case–Control design was used to examine MF changes in two groups of female office workers when they were subjected to controlled doses of computer work involving prolonged static posture, increased typing speed and increased typing force. The MF of four major neck–shoulder muscles were examined bilaterally and compared between groups.

The MF changes over time-at-task did not clearly illustrate any muscle fatigue mechanism. However, Case Group consistently showed trends for higher MF than the Control Group, and this pattern was observed in response to all three physical stressors. The consistent group differences in MF suggest different muscle recruitment strategies between symptomatic and asymptomatic office workers. These results implied that symptomatic individuals had altered motor control, which may have important implications in understanding the etiology of work-related musculoskeletal disorders.     

Ultrasonography,magnetic resonance imaging,radiography, and clinical assessment of inflammatory and destructive changes in fingers and toes of patients with psoriatic arthritis

The aim of the present study was to assess ultrasonography (US) for the detection of inflammatory and destructive changes in finger and toe joints, tendons, and entheses in patients with psoriasis-associated arthritis (PsA) by comparison with magnetic resonance imaging (MRI), projection radiography (x-ray), and clinical findings. Fifteen patients with PsA, 5 with rheumatoid arthritis (RA), and 5 healthy control persons were examined by means of US, contrast-enhanced MRI, x-ray, and clinical assessment. Each joint of the 2nd–5th finger (metacarpophalangeal joints, proximal interphalangeal [PIP] joints, and distal interphalangeal [DIP] joints) and 1st–5th metatarsophalangeal joints of both hands and feet were assessed with US for the presence of synovitis, bone erosions, bone proliferations, and capsular/extracapsular power Doppler signal (only in the PIP joints). The 2nd–5th flexor and extensor tendons of the fingers were assessed for the presence of insertional changes and tenosynovitis. One hand was assessed by means of MRI for the aforementioned changes. X-rays of both hands and feet were assessed for bone erosions and proliferations. US was repeated in 8 persons by another ultrasonographer. US and MRI were more sensitive to inflammatory and destructive changes than x-ray and clinical examination, and US showed a good interobserver agreement for bone changes (median 96% absolute agreement) and lower interobserver agreement for inflammatory changes (median 92% absolute agreement). A high absolute agreement (85% to 100%) for all destructive changes and a more moderate absolute agreement (73% to 100%) for the inflammatory pathologies were found between US and MRI. US detected a higher frequency of DIP joint changes in the PsA patients compared with RA patients. In particular, bone changes were found exclusively in PsA DIP joints. Furthermore, bone proliferations were more common and tenosynovitis was less frequent in PsA than RA. For other pathologies, no disease-specific pattern was observed. US and MRI have major potential for improved examination of joints, tendons, and entheses in fingers and toes of patients with PsA.     

Negotiating precarious labour relations: dynamics of vulnerability and reciprocity between Chinese employers and their migrant workers in Santiago,Chile

Precarious labour research has highlighted the multidimensional factors shaping migrants’ vulnerability to labour exploitation. This article takes a different approach by attending to the possible reciprocity in labour relations– despite unequal power dynamics– particularly when workplaces are small and involve daily interactions between migrant workers and migrant employers. Methodology is based on observations in Chinese-run retail shops and restaurants in Santiago, and interviews with Chinese employers and their Latin American migrant employees of diverse backgrounds. Proposing the concept of “precarious labour relations”, we examine the independent and shared uncertainties between migrant employers and workers who are differently marginalized through race/migrant status axes in Chile. Analyzing dynamics of hierarchy, (mis)trust, and reciprocity in how these actors negotiate precarity and security as workers and/or migrants, we complicate dichotomies of exploitation and resistance in migrant labour research, by foregrounding the multidimensional relationship between employers and workers when both are racialized migrants and minorities.     

Factors that may mediate the relationship between physical activity and the risk for developing knee osteoarthritis

Studies investigating the effect of physical activity on risk for developing osteoarthritis at weight-bearing joints have reported conflicting results. We examine evidence to suggest that this may be due to the existence of subgroups of individuals who differ in their response to physical activity, as well as methodological issues associated with the assessment of knee joint structure and physical activity. Recommendations for future studies of physical activity and the development of knee osteoarthritis are discussed.     

The foraging ecology of the army ant Eciton rapax: an ergonomic enigma?

Abstract. 1. The army ant Eciton rapax (F. Smith) produces longer raid systems than any other member of its genus and it is a specialist predator of forest floor and understory ants such as species of Camponotus, Odontomachus and Pachycondyla.
2. Allometrical analysis confirms that E. rapax is the only member of its genus without distinct physical castes among its workers: its foraging population is entirely monomorphic and there are no majors.
3. The workers of E. rapax are distributed over a considerable size range, and there are distinct divisions of labour within these colonies: small workers tend to stay in the nests and among the larger foraging workers those retrieving prey items are significantly bigger than the rest.
4. An analysis of foraging efficiency and worker performance in E. rapax suggests that transport costs, resulting from the great distances that workers travel during raids and emigrations, are one of the selection pressures that have favoured the evolution of large monomorphic workers in this species.     

Division of labour influences the rate of ageing in weaver ant workers

The evolutionary theory of ageing predicts that the timing of senescence has been primarily shaped by the extrinsic mortality rate, which causes selection intensity to decline over time. One difficulty in testing the evolutionary theory of ageing is that extrinsic mortality risk is often confounded with body size and fecundity, which may also directly affect lifespan. Social insects with a pronounced division of labour between worker castes provide a unique opportunity to study the direct effect of extrinsic mortality on the evolution of ageing rates independently of body size, reproductive effort and genetic configuration. In the weaver ant, Oecophylla smaragdina, the major (large) workers perform the risky tasks outside the nest, while the minor (small) workers stay within the highly protected arboreal nest. Hence, this pronounced division of labour is associated with high differences in extrinsic mortality risks. The evolutionary theory of ageing predicts that the minor workers should have a longer intrinsic lifespan than the major workers. In line with this prediction, we found that in a protected environment the minor workers lived significantly longer than the major workers did. Hence, the ageing rate appears to have been moulded by variation in the extrinsic mortality rate independently of size, reproductive effort and genetic configuration.     

Unstable Stifles without Clinical or Radiographic Osteoarthritis in Young Goats: An Experimental Study

Thirteen young, castrated male goats had instability of one stifle (knee joint) created by surgical transection of the cranial cruciate ligament, but did not develop any signs of osteoarthritis (OA) in treated joints when confined in limited space for 8 months. At the end of the experiment, the instability in the stifles had not improved, the joints were normal at radiographic examination, there were no signs of inflammation in the synovial membrane or joint capsule, and fibrosis in these tissues was not evident. The articular cartilage was normal both visually and histologically. This may indicate that the young age of the goats and the restricted physical activity on soft floor had prevented the expected development of OA in the experimantally operated joints. Synovial fluid volumes and proteoglycan concentration were measured in the treated and control joints in 6 of the goats. There seemed to be increased quantity of the proteoglycan aggrecan in the synovial fluid from the treated joints compared to the contralateral joints throughout the course of this study. It was concluded that the turnover of aggrecan in the articular cartilage of the treated joints may have been increased.     

Joint forces in the human pelvis-leg skeleton during walking

For the calculation of the forces in the hip, knee and ankle joints during walking the knowledge of the three-dimensional movements of the human body and of the forces between foot and ground is a prerequisite. It is shown how this information may be obtained and what accuracy is obtainable. For the calculation of the statically indeterminate system of the lower limbs, consisting of muscles, bones and joints an optimization method is applied. The optimization criterion is the minimization of the muscle forces. Measurements were taken with seventeen male and five female persons. The maximum joint forces are plotted against gait speed, body weight and body size. In addition some statistical distributions are presented.     

Research on office environment evaluation and worker fatigue

1. 1. The purpose of this research was to study the relationship between indoor environment and fatigue by analyzing office workers' fatigue and evaluation of indoor environment according to occupation.

2. 2. This study concerned office workers' fatigue (before and after work), questionnaires on indoor environment, and measurement of the physical environment. The subject (562 people) were businessmen, interior designers, and salesmen.

3. 3. The result of this study showed that there was a high correlation between the office workers' feeling of fatigue and the office environment.

4. 4. This research demonstrated that the workers of each type of occupation responde differently to similar office environments.

Imaging of blocks in the spine with bone scintigraphy (SPECT)]

INTRODUCTION: One of the most important tasks of manual therapists is the treatment of hypomobile intervertebral joints. Such conditions of the spine are treated with various manipulations or mobilisation. The pathophysiological basis of hypomobility is still under discussion. Objective criteria for the diagnosis of impaired spinal mobility are not available. Nor is any substrate detectable by X-ray, computed tomography or NMR. AIM: To find evidence of a biomechanical alteration of hypomobile intervertebral joints with the aid of SPECT (Single Photon Emission Computed Tomography). STUDY DESIGN: 13 outpatients with back pain but otherwise healthy attending the Orthopaedic University Hospital in Marburg were examined by manual medical means, and were found to have hypomobility of an intervertebral joint. In addition, the spines of these patients were examined with SPECT (bone scanning). RESULTS: Comparison of the results of physical examination and bone scanning revealed that in 75% of all the cases the location (spinal segment) of the hypomobility identified by each of the two methods was identical. In 83%, they were in agreement on which of the sides (facet joint) was affected.     

Application of a predictive approach to estimate exposure to non‐smoking urban sub‐populations to background levels of Benzene in Ontario

An indirect approach was used to estimate exposure to background levels of atmospheric benzene for a selection of Ontario non‐smoking urban sub‐populations. Activity codes obtained from nationally representative time‐budget surveys were allocated to five general microenvironments (home, work (or school), outdoors, commuting, and other indoors) and further combined with inhalation rates corresponding to specific levels of physical activity in order to develop average activity patterns for six sub‐populations believed to be differently exposed to atmospheric benzene in urban areas (children, teenagers, office workers, outdoor workers, transit workers, and seniors). These activity patterns were then combined with representative concentrations of benzene measured in the selected microenvironments in Ontario in order to evaluate exposure. Two metrics were used for this purpose, integrated exposure and potential average daily dose (intake). Potential lifetime average daily doses were also estimated for three composite sub‐groups representing average office, outdoor, and transit workers. A probabilistic approach using a Monte‐Carlo sampling procedure was used in order to estimate possible ranges of exposures experienced by the various sub‐populations. Results obtained suggested that the highest daily integrated exposure (mean: 131 μg‐hrs/m³) was associated with the average transit worker while comparable levels were estimated for the other sub‐populations investigated (mean: 77–86 μg‐hrs/m³). These levels corresponded to 24‐hours time‐weighted average (TWA)‐equivalent concentrations of 5.5 μg/m³ and 3.5 μg/m³, respectively. Statistical distributions of integrated exposures obtained with the probabilistic approach indicated levels as high as 343 μg‐hrs/m³ (97.5th percentile) in the case of the average transit worker, corresponding to TWA‐equivalents in excess of 15 μg/m³. When levels of physical activities and inhalation rates were integrated in the calculation of exposure, the highest potential average daily dose was found to be associated with the average child (mean: 3.1 μg/kg‐day; 97.5th percentile: 6.0 μg/kg‐day) whereas comparable amounts were estimated for teenager and transit workers (mean: 2.1 μg/kg‐day; 97.5th: 4.1 and 6.9 μg/kg‐day, respectively). Indoor microenvironments (home, office/school, other indoors) were identified as the major contributors to total exposure and intake of benzene (≥50%) although their relative importance varied depending on the exposure metric utilized. Potential lifetime average daily doses estimated for transit workers varied from 2.1 (mean) to 5.4 (97.5th) μg/kg‐day. This was slightly higher than those estimated for the average office and outdoor workers (mean: 1.5–1.7 μg/kg‐day). These projections suggest that average non‐smoking children and teenagers are the most exposed sub‐populations among those investigated to background levels of atmospheric benzene as a result of their daily activities. However, these projections must be interpreted with caution in view of uncertainties associated with some of the assumptions adopted, the limited database used to document benzene levels, and as a result of unaccounted sources of emissions which, under certain circumstances, can significantly modify these conclusions.     

Division of Labour among Workers in the Termite,Reticulitermes fukienensis (Isoptera: Rhinotermitidae)

To investigate division of labour in Reticulitermes fukienensis, worker and larval subgroups were established in laboratory cultures and task performance patterns of different-sized workers and larvae were recorded. Five categories of subgroups were established based on head width differences: small larvae (SL); large larvae (LL); small workers (SW); medium workers (MW); and large workers (LW). Subgroups were compared for their ability to carry out the following tasks: tunnel construction; covered gallery construction; gallery repair; and feeding. Larval subgroups were found to carry out none of the tasks investigated. They did not feed or build covered galleries or underground tunnels. Temporal polyethism occurred among workers of different size groups. Covered foraging galleries were exclusively built and tunnels were predominantly built by older workers (i.e. MW and especially LW). Remarkably, most SW were apparently unable to burrow into the soil, something that all LW did within 3 d and 95% of MW did within 5 d. Surprisingly, LW ate 8.5 and 65.5 times as much food (i.e. filter paper) as MW and SW, respectively, although their average body weights were, respectively, only approximately two and four times that of MW and SW. MW carried out all four tasks that LW performed, although MW were typically less efficient. This contrasts with the hypothesis that different instars of termites should carry out different non-overlapping tasks. Large workers carried out most of all tasks compared with other worker sizes. The only exception was for gallery repair where repair rate by LW did not differ significantly from MW. The predominance of tasks carried out by larger (i.e. older) workers indicates a possible new pattern for division of labour in these lower termites. This contrasts with the pattern of organization of division of labour in the social Hymenoptera.     

Three Groups in the 28 Joints for Rheumatoid Arthritis Synovitis – Analysis Using More than 17,000 Assessments in the KURAMA Database

Rheumatoid arthritis (RA) is a joint-destructive autoimmune disease. Three composite indices evaluating the same 28 joints are commonly used for the evaluation of RA activity. However, the relationship between, and the frequency of, the joint involvements are still not fully understood. Here, we obtained and analyzed 17,311 assessments for 28 joints in 1,314 patients with RA from 2005 to 2011 from electronic clinical chart templates stored in the KURAMA (Kyoto University Rheumatoid Arthritis Management Alliance) database. Affected rates for swelling and tenderness were assessed for each of the 28 joints and compared between two different sets of RA patients. Correlations of joint symptoms were analyzed for swellings and tenderness using kappa coefficient and eigen vectors by principal component analysis. As a result, we found that joint affected rates greatly varied from joint to joint both for tenderness and swelling for the two sets. Right wrist joint is the most affected joint of the 28 joints. Tenderness and swellings are well correlated in the same joints except for the shoulder joints. Patients with RA tended to demonstrate right-dominant joint involvement and joint destruction. We also found that RA synovitis could be classified into three categories of joints in the correlation analyses: large joints with wrist joints, PIP joints, and MCP joints. Clustering analysis based on distribution of synovitis revealed that patients with RA could be classified into six subgroups. We confirmed the symmetric joint involvement in RA. Our results suggested that RA synovitis can be classified into subgroups and that several different mechanisms may underlie the pathophysiology in RA synovitis.     

Regulation of biomechanical signals by NF-kappaB transcription factors in chondrocytes

Physical therapies and exercise are beneficial not only for physiological recovery in inflamed or injured joints, but also for promoting a homeostatic equilibrium in healthy joints. Human joints provide the pivot points and physiological hinges essential for ambulation and movement to the body, and it is this mobility that in return promotes the health of the joints. But how mobilization regulates the joint microenvironment at the molecular level has remained enigmatic for many years. Recent advances in joint biomechanics and molecular approaches have facilitated an enriched understanding of how joints operate. Consequently, the mechanisms active during joint inflammation that lead to arthritic conditions, both in vivo in animal models, and in vitro at cell and tissue levels, have become increasingly detailed and defined. These efforts have produced mounting evidences supporting the premise that biomechanical signals play a fundamental role in both the etiopathogenesis of arthritic diseases and in the physiological restoration of joints. This report aims to summarize current peer-reviewed literature and available experimental data to explain how the signals generated by mechanical forces/joint mobilization generate beneficial effects on inflamed articular cartilage, and to propose the basis for using appropriate physical therapies for the optimal benefit to the patient suffering from joint associated injuries.     

The contribution of the wrist, elbow and shoulder joints to single-finger tapping

We aimed to determine the role of the wrist, elbow and shoulder joints to single-finger tapping. Six human subjects tapped with their index finger at a rate of 3 taps/s on a keyswitch across five conditions, one freestyle (FS) and four instructed tapping strategies. The four instructed conditions were to tap on a keyswitch using the finger joint only (FO), the wrist joint only (WO), the elbow joint only (EO), and the shoulder joint only (SO). A single-axis force plate measured the fingertip force. An infra-red active-marker three-dimensional motion analysis system measured the movement of the fingertip, hand, forearm, upper arm and trunk. Inverse dynamics estimated joint torques for the metacarpal-phalangeal (MCP), wrist, elbow, and shoulder joints. For FS tapping 27%, 56%, and 18% of the vertical fingertip movement were a result of flexion of the MCP joint and wrist joint and extension of the elbow joint, respectively. During the FS movements the net joint powers between the MCP, wrist and elbow were positively correlated (correlation coefficients between 0.46 and 0.76) suggesting synergistic efforts. For the instructed tapping strategies (FO, WO, EO, and SO), correlations decreased to values below 0.35 suggesting relatively independent control of the different joints. For FS tapping, the kinematic and kinetic data indicate that the wrist and elbow contribute significantly, working in synergy with the finger joints to create the fingertip tapping task.