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Biomedical subjects

A J van der Beek

Publications and source records attributed to A J van der Beek.

At least 19 recordsLinked to original sources
PubMed2007

Fatigue effects on tracking performance and muscle activity.

It has been suggested that fatigue affects proprioception and consequently movement accuracy, the effects of which may be counteracted by increased muscle activity. To determine the effects of fatigue on tracking performance and muscle activity in the M. extensor carpi radialis (ECR), 11 female participants performed a 2-min tracking task with a computer mouse, before and immediately after a fatiguing wrist extension protocol. Tracking performance was significantly affected by fatigue. Percentage time on target was significantly lower in the first half of the task after the fatigue protocol, but was unaffected in the latter half of the task. Mean distance to target and the standard deviation of the distance to target were both increased after the fatigue protocol. The changed performance was accompanied by higher peak EMG amplitudes in the ECR, whereas the static and the median EMG levels were not affected. The results of this study showed that subjects changed tracking performance when fatigued in order to meet the task instruction to stay on target. Contrary to our expectations, this did not lead to an overall higher muscle activity, but to a selective increase in peak muscle activity levels of the ECR.

Adult↗
PubMed2006

Should office workers spend fewer hours at their computer? A systematic review of the literature.

Worldwide, millions of office workers use a computer. Reports of adverse health effects due to computer use have received considerable media attention. This systematic review summarises the evidence for a relationship between the duration of work time spent using the computer and the incidence of hand-arm and neck-shoulder symptoms and disorders. Several databases were systematically searched up to 6 November 2005. Two reviewers independently selected articles that presented a risk estimate for the duration of computer use, included an outcome measure related to hand-arm or neck-shoulder symptoms or disorders, and had a longitudinal study design. The strength of the evidence was based on methodological quality and consistency of the results. Nine relevant articles were identified, of which six were rated as high quality. Moderate evidence was concluded for a positive association between the duration of mouse use and hand-arm symptoms. For this association, indications for a dose-response relationship were found. Risk estimates were in general stronger for the hand-arm region than for the neck-shoulder region, and stronger for mouse use than for total computer use and keyboard use. A pathophysiological model focusing on the overuse of muscles during computer use supports these differences. Future studies are needed to improve our understanding of safe levels of computer use by measuring the duration of computer use in a more objective way, differentiating between total computer use, mouse use and keyboard use, attaining sufficient exposure contrast, and collecting data on disability caused by symptoms.

Arm↗
PubMed2006

Do work-related physical factors predict neck and upper limb symptoms in office workers?

OBJECTIVES: The objective of this study was to examine the influence of physical exposure at work on neck and upper limb symptoms in office workers. METHODS: Data were used from a prospective cohort study with a follow-up period of 3 years. Independent variables were physical exposure at work, observed and self-reported. Outcome measures were neck-shoulder symptoms and elbow-wrist-hand symptoms. Data were analyzed with the generalized estimating equation (GEE) method, with adjustment for age, gender, psychosocial work characteristics and the outcome at baseline. RESULTS: Neck rotation was associated with neck-shoulder symptoms in the analyses with observed data (OR: 1.57; CI: 0.99-2.50) as well as those with self-reported data (OR: 1.43; CI: 1.02-2.01). Neck extension was also statistically significantly associated with neck-shoulder symptoms (OR: 2.42; CI: 1.22-4.80), but only self-reported data were available. Neck flexion, self-reported wrist pronation, self-reported arm elevation and self-reported duration of computer work, were not associated with symptoms. An indication was found of an adverse effect on neck-shoulder symptoms of long working days and on elbow-wrist-hand symptoms of self-reported wrist flexion and full-time work or longer compared to part-time work. CONCLUSIONS: Only a limited number of work-related physical factors were related to neck and upper limb symptoms in office workers. Only neck rotation and self-reported neck extension were identified as risk factors for neck-shoulder symptoms.

Administrative Personnel↗
PubMed2006

Counselling increases physical activity behaviour nine weeks after rehabilitation.

BACKGROUND: For people with disabilities, a physically active lifestyle can reduce the risk of secondary health problems and improve overall functioning. OBJECTIVES: To determine the effects of the sport stimulation programme "rehabilitation and sports" (R&S) and R&S combined with the daily physical activity promotion programme "active after rehabilitation" (AaR) on sport participation and daily physical activity behaviour nine weeks after inpatient or outpatient rehabilitation. METHODS: Subjects in four intervention rehabilitation centres were randomised to a group receiving R&S only (n = 315) or a group receiving R&S and AaR (n = 284). Subjects in six control rehabilitation centres (n = 603) received the usual care. Most common diagnoses were stroke, neurological disorders, and back disorders. Two sport and two daily physical activity outcomes were assessed with questionnaires seven weeks before and nine weeks after the end of rehabilitation. Data were analysed by intention to treat and on treatment multilevel analyses, comparing both intervention groups with the control group. RESULTS: The R&S group showed no significant change. Intention to treat analyses of the R&S+AaR group showed significant improvements in one sport (p = 0.02) and one physical activity outcome (p = 0.03). On treatment analyses in the R&S+AaR group showed significant improvements in both sport outcomes (p<0.01 and p = 0.02) and one physical activity outcome (p<0.01). CONCLUSIONS: Only the combination of R&S and AaR had increased sports participation and daily physical activity behaviour nine weeks after the end of inpatient or outpatient rehabilitation.

Activities of Daily Living↗
PubMed2005

How to prevent low back pain.

This chapter summarizes the European Guidelines for Prevention in Low Back Pain, which consider the evidence in respect of the general population, workers and children. There is limited scope for preventing the incidence (first-time onset) of back pain and, overall, there is limited robust evidence for numerous aspects of prevention in back pain. Nevertheless, there is evidence suggesting that prevention of various consequences of back pain is feasible. However, for those interventions where there is acceptable evidence, the effect sizes are rather modest. The most promising approaches seem to involve physical activity/exercise and appropriate (biopsychosocial) education, at least for adults. Owing to its multidimensional nature, no single intervention is likely to be effective at preventing the overall problem of back pain, although there is likely to be benefit from getting all the players onside. However, innovative studies are required to better understand the mechanisms and delivery of prevention in low back pain.

Exercise Therapy↗
PubMed2005

An economic evaluation of a proprioceptive balance board training programme for the prevention of ankle sprains in volleyball.

OBJECTIVES: To evaluate the cost effectiveness of a proprioceptive balance board training programme for the prevention of ankle sprains in volleyball. METHODS: A total of 116 volleyball teams participated in this study which was carried out during the 2001-2002 volleyball season. Teams were randomly allotted to an intervention group (66 teams, 628 players) or a control group (52 teams, 494 players). Intervention teams followed a prescribed balance board training programme as part of their warm up. Control teams followed their normal training routine. An ankle sprain was recorded if it occurred as a result of volleyball and caused the subject to stop volleyball activity. The injured player completed a cost diary for the duration of the ankle sprain. Analyses were performed according to the intention to treat principle. Mean direct, indirect, and total costs were calculated and were compared between the two groups. RESULTS: The total costs per player (including the intervention material) were significantly higher in the intervention group (36.99 (93.87)) than in the control group (18.94 (147.09)). The cost of preventing one ankle sprain was approximately 444.03. Sensitivity analysis showed that a proprioceptive balance board training programme aimed only at players with previous ankle sprains could be cost effective over a longer period of time. CONCLUSIONS: Positive effects of the balance board programme could only be achieved at certain costs. However, if broadly implemented, costs associated with the balance board programme would probably be lower.

Adult↗
PubMed2004

The effect of physical activity in leisure time on neck and upper limb symptoms.

BACKGROUND: : Little is known of the preventive effects of physical activity in leisure time on neck and upper limb symptoms. METHODS: : A cohort of 1742 employees was selected from a prospective cohort study with a follow-up period of 3 years. Independent variables were sporting activities and physically active commuting. Outcome measures were neck/shoulder symptoms and elbow/wrist/hand symptoms as well as sickness absence due to these symptoms. To analyze the data, the generalized estimating equation (GEE) method was used, with adjustment for individual characteristics, such as age, gender, lifestyle, and the outcome at baseline. RESULTS: : Practicing sports for at least 10 months a year decreased the risk of neck/shoulder symptoms (OR: 0.82; CI: 0.67-0.99), sickness absence (OR: 0.48; CI: 0.28-0.84), and long-term sickness absence (OR: 0.37; CI: 0.17-0.84) due to neck or upper limb symptoms. A high mean intensity (> or = 3 h per week) of sporting activities had less effect than the continuation of these activities throughout the year. CONCLUSION: : Sustained sporting activities have a favorable effect on neck/shoulder symptoms and on sickness absence due to neck or upper limb symptoms. An effect of physically active commuting could not be demonstrated, although there was a tendency towards a favorable effect on sickness absence.

Age Distribution↗
PubMed2004

Worksite health promotion using individual counselling and the effectiveness on sick leave; results of a randomised controlled trial.

AIMS: To investigate the effectiveness of a worksite health promotion programme by individual counselling on sick leave. METHODS: Three municipal services of Enschede, the Netherlands, participated in this trial. A total of 299 civil servants were measured at baseline and were randomised by cluster into the intervention (n = 131) or the control group (n = 168). During nine months, subjects in the intervention group received a total of seven consultations, particularly aimed at increasing their physical activity level and improving their dietary habits. Both the intervention and the control subjects received written information as to several lifestyle factors. Sick leave data regarding the nine month intervention period (from May until January) were collected from each municipal service's personnel department. In addition, sick leave data concerning the nine month period pre- and post-intervention were collected. Sick leave data were analysed using multilevel analysis. RESULTS: For both groups, the mean sick leave rate during the intervention increased compared to before the intervention. After the intervention period, the control group increased even more (from 22.9 to 27.6 days), whereas the intervention group slightly decreased (from 21.5 to 20.5 days). Median values of sick leave rate decreased for both groups. No statistically significant intervention effect was found. In both groups, the mean sick leave frequency slightly decreased over time (intervention effects were not significant). CONCLUSIONS: Results showed no significant effect of individual counselling on sick leave. Continued research investigating the effectiveness of this individual counselling programme on several health related outcomes is useful to clarify the trend observed in sick leave.

Adult↗
PubMed2004

The effectiveness of ergonomic interventions on return-to-work after low back pain; a prospective two year cohort study in six countries on low back pain patients sicklisted for 3-4 months.

AIMS: To study occurrence and effectiveness of ergonomic interventions on return-to-work applied for workers with low back pain (LBP). METHODS: A multinational cohort of 1631 workers fully sicklisted 3-4 months due to LBP (ICD-9 codes 721, 722, 724) was recruited from sickness benefit claimants databases in Denmark, Germany, Israel, Sweden, the Netherlands, and the United States. Medical, ergonomic, and other interventions, working status, and return-to-work were measured using questionnaires and interviews at three months, one and two years after the start of sickleave. Main outcome measure was time to return-to-work. Cox's proportional hazards model was used to calculate hazard ratios regarding the time to return-to-work, adjusted for prognostic factors. RESULTS: Ergonomic interventions varied considerably in occurrence between the national cohorts: 23.4% (mean) of the participants reported adaptation of the workplace, ranging from 15.0% to 30.5%. Adaptation of job tasks and adaptation of working hours was applied for 44.8% (range 41.0-59.2%) and 46.0% (range 19.9-62.9%) of the participants, respectively. Adaptation of the workplace was effective on return-to-work rate with an adjusted hazard ratio (HR) of 1.47 (95% CI 1.25 to 1.72; p < 0.0001). Adaptation of job tasks and adaptation of working hours were effective on return-to-work after a period of more than 200 days of sickleave with an adjusted HR of 1.78 (95% CI 1.42 to 2.23; p < 0.0001) and 1.41 (95% CI 1.13 to 1.76; p = 0.002), respectively. CONCLUSIONS: Results suggest that ergonomic interventions are effective on return-to-work of workers long term sicklisted due to LBP.

Absenteeism↗
PubMed2003

Short term effect of feedback on fitness and health measurements on self reported appraisal of the stage of change.

BACKGROUND: An individual's current status of physical activity and nutrition and readiness to change can be determined using PACE assessment forms. Practitioners have suggested that feedback on the fitness and health components can produce a change in a subject's awareness of their behaviour and thereby lead to a beneficial change in stage of behaviour change. OBJECTIVE: To evaluate the short term effect of personalised feedback on fitness and health status on self reported appraisal of the stage of change. METHODS: A total of 299 civil servants were randomised to an intervention or a reference group. After having been tested for fitness and health, the intervention group received immediate feedback on their test results, whereas the reference group did not. PACE assessment forms were completed twice: before testing and after testing (reference group), or after testing and feedback (intervention group). The time interval between was one hour. The influence of feedback was determined using a x(2) test and analysis of variance. RESULTS: On the basis of the x(2) test, no significant effect of feedback was found on the stage of change of physical activity, nor on the stage of change with regard to nutrition. Analysis of variance results showed no significant effect on the raw PACE score as to physical activity, intake of fruit and vegetables and dietary fat. However, a significant effect was observed on the PACE score of "calorie intake and weight management". Subjects in the intervention group significantly more often regressed on their PACE score on this topic than the reference subjects. CONCLUSIONS: Feedback at baseline on measurements of an intervention study can influence PACE scores and can be considered as a small but relevant start of the intervention itself.

Adaptation, Psychological↗
PubMed2003

Medical staff in emergency situations: severity of patient status predicts stress hormone reactivity and recovery.

BACKGROUND: Although repetitive exposure to stressful situations is thought to habituate the physical stress responses, work stress is experienced by medical personnel in emergency and intensive care units; performance should, however, remain stable over time. AIMS: To investigate the neuroendocrine reactions (reactivity during and recovery after work) in experienced emergency caregivers during emergency situations. METHODS: A within subjects pre-post design was studied in the natural work environment of 20 municipal Dutch emergency caregivers. A stress protocol was developed in which the biomarker cortisol was measured in saliva at baseline, during the emergency period, and during recovery. Four scenarios were tested between subjects in which the severity of the emergency situation and the time of day were taken into account. RESULTS: Greater endocrine reactions were shown during and after the handling of patients in direct life threatening situations during morning hours compared to the handling of patients who were not in direct life threatening situations.

Adult↗
PubMed2002

Pushing and pulling in association with low back and shoulder complaints.

AIMS: To examine the association between exposure to pushing/pulling at work and low back and shoulder complaints. METHODS: A cross sectional questionnaire survey was carried out among 434 workers from several companies with mainly pushing/pulling tasks. From the same companies 188 workers without physically demanding tasks served as reference. The questionnaire was used to assess the exposure to pushing/pulling and other physical risk factors for low back and shoulder complaints. Mean scores at company level were used to classify groups into medium and high exposed to pushing/pulling and a reference group. Psychosocial factors at work were also assessed. Several pain related questionnaires were used to assess the 12 month prevalence of low back and shoulder complaints in three dimensions: trouble (ache, pain, discomfort), pain intensity, and disability. Prevalence rate ratios (PRs) were calculated using Cox's proportional hazards regression analysis. RESULTS: The 12 month prevalence of low back complaints was almost equal for all three groups. The prevalence of shoulder complaints increased with an increase in exposure level. Adjusted PRs showed that the high exposed group had an increased risk for low back complaints compared to the reference group. For all dimensions of shoulder complaints a clear tendency towards a dose-response relation was observed. The high exposed group had significant PRs for shoulder complaints, ranging from 2.09 to 6.37. Generally, psychosocial factors had a confounding effect for pain intensity and disability, but not for trouble. CONCLUSIONS: For shoulder complaints a dose-response relation was observed for exposure to pushing/pulling. Low back complaints were less consistently associated with pushing/pulling. Stronger associations were observed for more severe cases of low back and shoulder complaints. It is hypothesised that work related psychosocial factors affect these associations.

Adult↗
PubMed2001

Evaluation of methods to assess push/pull forces in a construction task.

The objective of the present study was to determine the validity of methods to assess push/pull forces exerted in a construction task. Forces assessed using a hand-held digital force gauge were compared to those obtained using a highly accurate measuring frame. No significant differences were found between the methods, except for peak push forces, for which the forces assessed with the force gauge were significantly lower than those assessed with the measuring frame. When the construction task was reproduced close to the actual workplace by simulation against a fixed object using the force gauge, all exerted forces on the force gauge were significantly lower than those on the measuring frame, except for mean pull forces. When self-reports were compared to the exerted forces on the measuring frame, the construction workers overestimated the exerted push/pull forces by 50%. In conclusion, when applied for direct measurements, the force gauge can be used to validly assess push/pull forces at the workplace.

Adult↗
PubMed2001

The relation between work-induced neuroendocrine reactivity and recovery, subjective need for recovery, and health status.

OBJECTIVES: The purpose of this cross-sectional study with repeated measurements was to find out to what extent neuroendocrine reactivity during work and neuroendocrine recovery from work, and work characteristics, are related to subjective need for recovery and perceived health status. METHODS: Neuroendocrine reactivity and recovery were studied in 59 subjects by measuring urinary adrenaline and cortisol repeatedly during five consecutive days. Measures of work characteristics, subjective need for recovery, and health status were obtained by self-reports. Two hierarchical multiple linear regression analyses were performed. RESULTS: The work characteristics alone explained 39% and 28% of the variation in subjective need for recovery and health status, respectively, while these figures rose to 49% and 53% in the full models. Significant neuroendocrine contributors were found for cortisol in reactivity during work and recovery immediately after work and recovery during the day off-work, and for adrenaline in baseline level and recovery during the day off-work. Job characteristics contributed significantly as well. CONCLUSION: Both neuroendocrine measures and work characteristics were predictors for the amount of perceived need for recovery after work as well as for health status. The results are consistent with the cognitive activation theory of stress.

Adult↗
PubMed2001

The effect of tape, braces and shoes on ankle range of motion.

Sport injuries are unwanted adverse effects accompanying participation in sports. In a wide variety of sports the most common location of injury is the ankle, frequently resulting from a forced plantar flexed inversion of the foot exceeding the physiological range of motion (ROM). Historically the purpose of external support systems is to prevent acute ankle injuries by restricting abnormal ankle ROM. It is believed that a superior restrictive effect also implies a superior preventive effect. The purpose of this review was to examine the literature regarding the restricting effect of adhesive taping, prophylactic ankle stabilisers (PAS) and high-top shoes on ankle ROM. It has been found that tape restricts ankle eversion and inversion ROM significantly following application. However, tape loosens significantly following standardised exercise and sports activities. Studies regarding PAS reported that both semi-rigid and nonrigid stabilisers give a significant post-application restriction of ankle inversion motion. The nonrigid stabilisers show loosening over time during exercise, while the semi-rigid stabilisers maintain their restrictive effect over the same time span. High-top shoes in comparison to low-top shoes are more effective in restricting mechanically imposed ankle inversion ROM. Low-top shoes, however, also limit mechanically imposed ankle inversion stress with the ankle in the position in which ankle injury occurs most frequently. One must keep in mind, however, that a superior mechanical restriction of ankle ROM does not necessarily imply a superior preventive effect. Only well-controlled randomised studies can show such an effect, and these studies have shown a reduction of ankle injury incidence for all 3 prophylactic measures reviewed.

Ankle Injuries↗
PubMed2001

Group-based measurement strategies in exposure assessment explored by bootstrapping.

OBJECTIVES: The precision of mean exposure to pushing was examined in 2 occupational groups using various combinations of the number of workers and measurements per worker. METHODS: The frequency and duration of pushing of the 2 occupational groups was assessed using onsite observation. All data were divided into successive periods of 30 minutes of observation. The precision of the group mean exposure to pushing was expressed by 90% confidence intervals obtained by bootstrapping. The effect on the confidence interval of varying numbers of workers and numbers of periods per worker was examined. RESULTS: For both occupational groups there was little precision to be gained when >10 workers were observed. Within the maximum number of workers used in the bootstrap simulations, it appeared that, beyond 10 workers, the confidence intervals decreased by <5% for every worker that was added, when each worker was observed at least 8 periods of 30 minutes. If workers were observed exactly 4 periods of 30 minutes per worker, an additional 4 workers were required to compensate for the loss of precision. An unbalanced strategy with approximately 8 periods of 30 minutes per worker hardly decreased the precision of the group mean, however. CONCLUSIONS: The precision of the group-based mean exposure to pushing is influenced by the number of workers observed and by the number of repeated measurements per worker. In the planning of measurement strategies, it is advisable to account for possible sources of variance in advance and to assess the exposure variability.

Adult↗
PubMed2000

A comparison of approaches to modeling the relationship between ergonomic exposures and upper extremity disorders.

BACKGROUND: For a study of upper extremity musculoskeletal disorders among automobile manufacturing workers, an ergonomic exposure index was constructed by summing ten psychophysical (interview) items. Here we explore the sensitivity of the exposure-response relationship to the formulation of that index. METHODS: Five alternative exposure indices were constructed: three a priori weighting schemes and two sets of weights derived from multivariate regression coefficients. In addition, structural equation modeling was performed with LISREL. RESULTS: The original index and a priori weighting schemes had similar associations with upper extremity disorders, adjusted for nonoccupational covariates. A reasonable model fit was achieved in LISREL after two modifications; the standardized solution showed that nonneutral postures were significantly related to upper extremity signs and symptoms. CONCLUSIONS: In this large population, with adequate range of exposures, the exposure-response relationship appeared generally robust to the mathematical formulation of the exposure index. Among the available exposure variables, postural strain had the strongest association.

Adult↗