The impact of the COVID-19 pandemic on childhood obesity rates, by Health Board area, in Wales, UK

BACKGROUND

The aim of this study was to examine the possible impact of the coronavirus pandemic on rates of children living with obesity and severe obesity, by Health Board area in Wales.

METHODS

The pre-pandemic data consisted of all children included in the Wales Childhood Measurement Programme (2014/15-2018/19). The 2021/22 Child Measurement Programme data were used as the post-pandemic data set. Body mass index for obesity and severe obesity were calculated as 95th and 99.6th centiles, respectively.

RESULTS

Of the 163 277 children measured pre-pandemic (2014/15 to 2018/19), the overall prevalence of children with obesity and severe obesity were 12.1 and 3.2%, respectively. In the post-pandemic year (2021/22), obesity increased to 15.5% and severe obesity increased to 4.8%, with clear deprivation differentials (noting one of the seven Health Boards was unable to submit data post-pandemic). Two Health Boards had significantly higher rates of obesity post-pandemic compared to pre-pandemic. Increased levels of severe obesity were observed in all Health Boards with available data.

CONCLUSION

The post-pandemic rise in obesity and severe obesity in young children living in Wales demonstrates a need for more work on the prevention of obesity and severe obesity, targeting the early years and areas of socio-economic disadvantage.

Association between children living with obesity and Mental Health problems: a data analysis of the Welsh Health Survey, UK

BACKGROUND

Obesity and mental health problems in children are both significant and growing public health issues. There is mixed evidence on the relationship between obesity and mental health in children. This study examines the association between obesity and mental health problems in a nationally representative sample of children using the Welsh Health Survey for Children (n = 11,279 aged 4-15 years).

METHODS

The Chi-square test assessed the difference in the proportion of children reporting abnormal mental health scores (strengths and difficulties score ≥ 20) in children living with obesity (≥ 95 centile for age and sex). Then, a multivarible logistic regression was used to assess any association after accounting for confounding variables.

RESULTS

There were 1,582 children living with obesity in the study (19.6%). The Chi-square test indicated a significant difference in the proportion of children with abnormal mental health scores in children living with obesity (p = 0.001). This study found a very small but significant positive association between mental health and childhood obesity after accounting for confounding variables, Odds Ratio 1.02 (95%CI: 1.01 to 1.02, p = 0.001). However, socio-economic status was more of a driver.

CONCLUSION

The findings of this study show a very small but significant association between childhood obesity and mental health problems. The multivariable logistic regression indicates that the focus must remain on reducing health inequalities as this is a more important driver of child health and well-being. However, as a precautionary measure it may be worth considering if children living with obesity who present for weight-management services may benefit from a review of their mental health status to identify if further support is needed, if capacity allows, and this can be done in a supportive way.

Living with obesity is related to peer problems in children: A national cross-sectional study

AIM

To assess the association between obesity and problems in peer relations in children (4-15 years) in a large (n = 11 279), nationally representative data set.

METHODS

The chi-square test was used to compare differences in numbers of children with and without obesity and with and without abnormal peer problem scores. Then multivariable logistic regression was used to determine any association between obesity and peer problems after accounting for deprivation and life-style factors.

RESULTS

The results of the chi-square test were statistically significant (P < 0.05) for all groups except older girls. The multivariable logistic regression identified a small but significant association between children living with obesity and abnormal peer problems, odds ratio (OR) 1.06 (95% confidence interval, CI: 1.04-1.08, P = 0.001). When explored by subsets of children using sex and age, this association was strongest for girls aged 4-10 years, OR 1.12 (95% CI: 1.07-1.16, P = 0.001).

CONCLUSION

This is the first nationally representative study of children to identify this association in younger children. Whilst further research is needed to corroborate this finding, as a precautionary measure solutions to improve peer relationships and reduce stigma for school-aged children living with obesity are indicated.

Exploring the association between obesity and problems with peer relationships in children: a nationally representative cross-sectional study

BACKGROUND

The number of children living with obesity in the UK is increasing, and the rise has been exacerbated by the lockdowns during the COVID-19 pandemic, when school attendance was suspended and leisure activities were curtailed. Whether an association exists between obesity and problems with peer relationships in children has not been definitively answered because few datasets collect these data simultaneously. This study was aimed at exploring the relationship between obesity and peer problems in children after adjustment for multiple confounding factors.

METHODS

Children aged 4-15 years participating in the Welsh Health Survey for Children were included. The association between obesity (defined as body-mass index ≥95th centile) and peer relationship problems (as per the standard definitions in the internationally recognised Strengths and Difficulties Questionnaire) was assessed using multivariate logistic regression. Confounding factors included in the analysis were deprivation, meeting the UK Government's physical activity guidelines, and consumption of healthy foods (ie, daily fruit and vegetable consumption).

FINDINGS

11 279 children were included (5470 [48·5%] girls and 5801 [51·5%] boys). A small but significant association between children living with obesity and peer problems was identified (odds ratio [OR] 1·06 [95% CI 1·04-1·08]; p=0·0001) after accounting for confounding factors. The association was strongest for girls aged 4-10 years (OR 1·12 [95% CI 1·07-1·16]; p=0·0001).

INTERPRETATION

This study contributes to the small evidence base on this topic by investigating the association between obesity and peer problems in a large nationally representative sample from Wales, UK, and identifies a small but significant association between obesity and peer problems in children, particularly in younger girls. Existing evidence has established this association in adolescents, but this study is the first nationally representative analysis to identify this association in children. Additional research, ideally using large community datasets, is needed to complement these findings. In the meantime, as a precautionary measure, solutions to reduce bodyweight-based stigma and enhance peer relationships in school-aged children should be developed.

FUNDING

None.

International Horizon Scanning the impact of Covid-19 on increasing the health gap and vulnerability

 

The COVID-19 pandemic has caused unprecedented challenges for populations, health systems and governments worldwide, which have resulted in lasting economic, social and health impacts. The results of such have been felt disproportionately throughout society and existing vulnerabilities have been highlighted and heightened. A clear understanding of the extent of these vulnerabilities is needed in order to fully address the problem. The World Health Organization Collaborating Centre on Investment for Health and Well-being (WHOCC), Public Health Wales has developed a summary report focusing on the existing and emerging inequalities resulting from the pandemic, as identified through international evidence and learning from the International Horizon Scanning Reports. These reports, undertaken between May 2020 - August 2021, are based upon rapid evidence synthesis reviews of international literature. The summary report focuses on global learning and best practices in order to better understand and address the unequal impacts of the pandemic. The information has been categorised according to the five essential conditions required to enable a healthy life as presented within the WHO health equity conditions framework. The report provides evidence on groups most vulnerable to both direct and indirect impacts of the pandemic as well as promising practice to address the resulting inequity. Inequalities and related factors explored within the report include but are not limited to, level of deprivation and education. Taking a global perspective, this report summarises international evidence to support inclusive, sustainable, and equitable solutions, such as protecting economic well-being and taking an intergenerational lens in both response and recovery. To address and mitigate the impact of the pandemic upon vulnerable groups, collating and sharing international evidence and best practice has proven to support equitable long-term socio-economic and environmental recovery.

Key messages

• International learning provides vital insights to support recovery in Wales and beyond.

• Responses to the pandemic should address the needs of the vulnerable to reduce existing health gaps.

Prevalence of severe childhood obesity in Wales UK

BACKGROUND

In Wales, approximately one in eight children is obese (aged 4-5 years). The aim of this prevalence study was to examine the trends in severe childhood obesity and investigate any relationship with socioeconomic deprivation.

METHODS

Data for all children included as part of the Wales Childhood Measurement Programme (2013/14-2017/18) were utilized. Data on the number who had a body mass index above the 99.6th centile indicating severe obesity were calculated over time by sex and in relation to deprivation.

RESULTS

Of the 162 208 children measured between 2013/14 and 2017/18 (mean age 5.06 years, standard deviation 0.35 years), the overall prevalence of severe obesity was 3.1% (95% confidence interval [CI] 3.0-3.2%). This varies from 1.9% (95% CI 1.7-2.1%) in the least deprived areas to 3.9% (95% CI 3.7-4.0%) in the most deprived areas. Boys have higher prevalence of severe obesity than girls: 3.6% (95% CI 3.4-3.9%) of boys (n = 598) and 3.0% (95% CI 2.7-3.2%) of girls (n = 467) were categorized as severely obese in reception year in Wales in 2017/18. Prevalence has increased over time but this is not statistically significant.

CONCLUSION

This study found significantly higher levels of severe obesity in areas of socioeconomic deprivation. Levels of severe obesity were significantly higher in boys than in girls.

Bespoke regional blocks for axillary sentinel node biopsy

INTRODUCTION

Axillary sentinel node biopsy for melanoma is routinely performed under general anaesthesia. Emerging evidence has shown general anaesthetics are associated with increased mortality in the context of the COVID-19 pandemic. In the interest of patient safety, we have designed a series of bespoke axillary regional blocks enabling surgeons to remove nodes up to and including level III without the need for a general anaesthetic. The aim of this study was to assess the feasibility of performing axillary sentinel node biopsy under such blocks.

METHODS

Approval was granted by the Joint Study Review Committee on behalf of the Research and Ethics Department. Ten consecutive patients having axillary sentinel node biopsy for melanoma were included in this prospective study. Patients completed a Quality of Recovery-15 (QoR15) questionnaire preoperatively and 24 h postoperatively.

DISCUSSION

One patient had a positive sentinel node, the remining were negative. A significant reduction in time spent in hospital post-operatively (p = 0.0008) was observed. QoR15 patient reported outcome measures demonstrated high levels of satisfaction evidenced by lack of statistical difference between pre and post-operative scores (p = 0.0118). 80% of patients were happy to have a regional block and 90% were happy to attend hospital during the pandemic.

CONCLUSION

ASNB under regional block is safe, negates risks associated with performing GAs during the COVID-19 pandemic and facilitates quicker theatre turnover and discharge from hospital. Collaboration between anaesthetic and surgical teams has enabled this change in practice. There is a learning curve with both patient selection, education and development of technique.

Learning across the UK: a review of public health systems and policy approaches to early child development since political devolution

BACKGROUND

Giving children the best start in life is critical for their future health and wellbeing. Political devolution in the UK provides a natural experiment to explore how public health systems contribute to children's early developmental outcomes across four countries.

METHOD

A systematic literature review and input from a stakeholder group was used to develop a public health systems framework. This framework then informed analysis of public health policy approaches to early child development.

RESULTS

A total of 118 studies met the inclusion criteria. All national policies championed a 'prevention approach' to early child development. Political factors shaped divergence, with variation in national conceptualizations of child development ('preparing for life' versus 'preparing for school') and pre-school provision ('universal entitlement' or 'earned benefit'). Poverty and resourcing were identified as key system factors that influenced outcomes. Scotland and Wales have enacted distinctive legislation focusing on wider determinants. However, this is limited by the extent of devolved powers.

CONCLUSION

The systems framework clarifies policy complexity relating to early child development. The divergence of child development policies in the four countries and, particularly, the explicit recognition in Scottish and Welsh policy of wider determinants, creates scope for this topic to be a tracer area to compare UK public health systems longer term.

Is gambling an emerging public health issue for Wales, UK?

BACKGROUND

Not all gambling exposes people to the same level of harm. Harm from gambling is found at the individual, social (family and friends) and community levels. This includes financial hardship, psychological distress and interpersonal conflict or relationship breakdown. The harm from gambling to wider society includes fraud, theft, loss of productivity in the workforce and the cost of treating this addiction. The annual estimated excess cost of gambling for Wales is between £40 and £70 million.

METHODS

This study reviews the existing data sources and literature to ascertain if gambling is an emerging public health issue in Wales.

RESULTS

In Wales 61% of adults had gambled in the last year (1.5 million people). And 1.1% of the population (30 000 people) self-report as having a problem with gambling using either the Problem Gambling Severity Index or the Diagnostic and Statistical Manual of American Psychiatric Association tools. The 'ripple effect' of gambling harm can mean friends and family are highly impacted.

CONCLUSION

The existing data and literature together with the rapidly evolving developments in infrastructure demonstrate that gambling is an emerging public health issue in Wales. The impact on families and society warrants population level interventions to tackle this public health issue.

Risk factors for childhood obesity: a data analysis of the Welsh Health Survey

Background The prevalence of childhood obesity in Wales is 12%. It has been estimated that obesity will cost the NHS £10 billion a year by 2050 ( Government Office for Science 2007 ). Aim To determine important risk factors associated with childhood obesity from the data in the Welsh Health Survey 2008 to 2012. Method The analysis used survey data from 11,279 children aged 4-15 years. The lifestyle variables considered as potential risk factors for obesity included: intake of sugar-sweetened drinks; unhealthy food consumption; physical activity; and currently-treated illnesses. The sociodemographic and socioeconomic factors included: sex; age; Welsh Index of Multiple Deprivation quintile; National Statistics Socio-economic Classification; and housing tenure. Results A total of 1,582 (20%) children were obese. A significant association was found between obesity and having one illness - odds ratio (OR) 1.20 (95% confidence interval (CI): 1.05 to 1.38, P=0.008) and having two or more illnesses - OR 1.50 (95% CI: 1.22 to 1.85, P<0.001), and not meeting the physical activity recommendation - OR 1.33 (95% CI: 1.17 to 1.52, P<0.001). Conclusion Every child should meet the physical activity recommendation and those with an illness should receive a care plan to prevent or manage obesity, although this is difficult in the time available for children in clinics and consultations.

[Oral anticoagulant-associated intracerebral haemorrhage]

Intracerebral haemorrhage during treatment with oral anticoagulants is associated with high rates of morbidity and mortality. Impaired haemostasis can lead to progressive haematomas and, therefore, it should be identified early in order to initiate measures to reverse anticoagulation. Substitution of coagulation factors is essential in the treatment of these patients, but other intensive care measures such as blood pressure control are mandatory as well.

Using clinical practice variations as a method for commissioners and clinicians to identify and prioritise opportunities for disinvestment in health care: a cross-sectional study, systematic reviews and qualitative study

Background

NHS expenditure has stagnated since the economic crisis of 2007, resulting in financial pressures. One response is for policy-makers to regulate use of existing health-care technologies and disinvest from inefficiently used health technologies. A key challenge to disinvestment is to identify existing health technologies with uncertain cost-effectiveness.

Objectives

We aimed to explore if geographical variation in procedure rates is a marker of clinical uncertainty and might be used by local commissioners to identify procedures that are potential candidates for disinvestment. We also explore obstacles and solutions to local commissioners achieving disinvestment, and patient and clinician perspectives on regulating access to procedures.

Methods

We used Hospital Episode Statistics to measure geographical variation in procedure rates from 2007/8 to 2011/12. Expected procedure numbers for each primary care trust (PCT) were calculated adjusting for proxies of need. Random effects Poisson regression quantified the residual inter-PCT procedure rate variability. We benchmarked local procedure rates in two PCTs against national rates. We conducted rapid systematic reviews of two high-use procedures selected by the PCTs [carpal tunnel release (CTR) and laser capsulotomy], searching bibliographical databases to identify systematic reviews and randomised controlled trials (RCTs). We conducted non-participant overt observations of commissioning meetings and semistructured interviews with stakeholders about disinvestment in general and with clinicians and patients about one disinvestment case study. Transcripts were analysed thematically using constant comparison methods derived from grounded theory.

Results

There was large inter-PCT variability in procedure rates for many common NHS procedures. Variation in procedure rates was highest where the diffusion or discontinuance was rapidly evolving and where substitute procedures were available, suggesting that variation is a proxy for clinical uncertainty about appropriate use. In both PCTs we identified procedures where high local use might represent an opportunity for disinvestment. However, there were barriers to achieving disinvestment in both procedure case studies. RCTs comparing CTR with conservative care indicated that surgery was clinically effective and cost-effective on average but provided limited evidence on patient subgroups to inform commissioning criteria and achieve savings. We found no RCTs of laser capsulotomy. The apparently high rate of capsulotomy was probably due to the coding inaccuracy; some savings might be achieved by greater use of outpatient procedures. Commissioning meetings were dominated by new funding requests. Benchmarking did not appear to be routinely carried out because of capacity issues and concerns about data reliability. Perceived barriers to disinvestment included lack of collaboration, central support and tools for disinvestment. Clinicians felt threshold criteria had little impact on their practice and that prior approval systems would not be cost-effective. Most patients were unaware of rationing.

Conclusions

Policy-makers could use geographical variation as a starting point to identify procedures where health technology reassessment or RCTs might be needed to inform policy. Commissioners can use benchmarking to identify procedures with high local use, possibly indicating overtreatment. However, coding inconsistency and limited evidence are major barriers to achieving disinvestment through benchmarking. Increased central support for commissioners to tackle disinvestment is needed, including tools, accurate data and relevant evidence. Early engagement with patients and clinicians is essential for successful local disinvestment.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Views and experiences of hepatitis C testing and diagnosis among people who inject drugs: systematic review of qualitative research

BACKGROUND

Many developed countries are facing a major challenge to improve identification of individuals acutely and chronically infected with hepatitis C virus (HCV) infection. We explored the views and experiences of people who inject drugs (PWID) in relation to HCV testing, and diagnosis through a review and synthesis of qualitative research.

METHODS

Based on the thematic synthesis of qualitative research. Searches were conducted in 14 databases and supplemented by reference checking, hand searching of selected journals, and searches of relevant websites. Studies of any qualitative design that examined the views and experiences of, and attitudes towards, HCV testing and diagnosis among PWID or practitioners involved in their care were included. Key themes and sub-themes were systematically coded according to the meaning and content of the findings of each study which proceeded to the preparation of a narrative account of the synthesis.

RESULTS

28 qualitative studies were identified. We identified a number of overarching descriptive themes in the literature, finding overall that PWID hold complex and differing views and experiences of testing and diagnosis. Three major themes emerged: missed opportunities for the provision of information and knowledge; shifting priorities between HCV testing and other needs; and testing as unexpected and routine. Evidence of missed opportunities for the provision of knowledge and information about HCV were clear, contributing to delays in seeking testing and providing a context to poor experiences of diagnosis. Influenced by the nature of their personal circumstances, perceptions of the risk associated with HCV and the prioritisation of other needs acted both to encourage and discourage the uptake of HCV testing. Undergoing HCV testing as part of routine health assessment, and an unawareness of being testing was common. An unexpected positive diagnosis exacerbated anxiety and confusion.

CONCLUSION

This review has identified that there are modifiable factors that affect the uptake of HCV testing and experiences of HCV diagnosis among PWID. Intervention development should focus on addressing these factors. There is a need for further research that engages PWID from a diverse range of populations to identify interventions, strategies and approaches that they consider valuable.

Alcohol use, drunkenness and tobacco smoking in rural western Kenya

OBJECTIVES

To describe the prevalence of smoking and alcohol use and abuse in an impoverished rural region of western Kenya.

METHODS

Picked from a population-based longitudinal database of demographic and health census data, 72 292 adults (≥18 years) were asked to self-report their recent (within the past 30 days) and lifetime use of tobacco and alcohol and frequency of recent 'drunkenness'.

RESULTS

Overall prevalence of ever smoking was 11.2% (11.0-11.5) and of ever drinking, 20.7% (20.4-21.0). The prevalence of current smoking was 6.3% (6.1-6.5); 5.7% (5.5-5.9) smoked daily. 7.3% (7.1-7.5) reported drinking alcohol within the past 30 days. Of these, 60.3% (58.9-61.6) reported being drunk on half or more of all drinking occasions. The percentage of current smokers rose with the number of drinking days in a month (P < 0.0001). Tobacco and alcohol use increased with decreasing socio-economic status and amongst women in the oldest age group (P < 0.0001).

CONCLUSIONS

Tobacco and alcohol use are prevalent in this rural region of Kenya. Abuse of alcohol is common and likely influenced by the availability of cheap, home-manufactured alcohol. Appropriate evidence-based policies to reduce alcohol and tobacco use should be widely implemented and complemented by public health efforts to increase awareness of their harmful effects.

[Severe traumatic brain injury]

Traumatic brain injury is a leading cause of morbidity and mortality, especially under 45 years of age. The primary brain injury occurs at the moment of trauma and is defined by the direct damage to tissue. In contrast, secondary brain injury develops over time and is accessible to therapeutic interventions. Patients with severe traumatic brain injury have to be transferred to a specialized trauma centre in order to perform appropriate diagnostic and therapeutic procedures. These include surgical management of lesions (e.g. haematoma evacuation) as well as specific neurointensive care. Neurointensive care medicine principles such as treatment of increased intracranial pressure and advanced invasive neuromonitoring of brain tissue have to be followed.

Treatment of frozen shoulder by manipulation under anaesthetic and injection: does the timing of treatment affect the outcome?

The effect of timing of a manipulation under anaesthetic (MUA) and injection of corticosteroid and local anaesthetic for the treatment of frozen shoulder has attracted little attention to date. All studies describe a period of conservative treatment before proceeding to an MUA. Delay has been associated with a poorer outcome. We present a retrospective review of a prospectively collected, single-surgeon, consecutive series of 246 patients with a primary frozen shoulder treated by MUA within four weeks of presentation. The mean duration of presenting symptoms was 28 weeks (6 to 156), and time to initial post-operative assessment was 26 days (5 to 126). The Oxford shoulder score (OSS) improved by a mean of 16 points (Wilcoxon signed-ranks test, p < 0.001) with a mean OSS at this time of 43 (7 to 48). Linear regression analysis showed no correlation between the duration of presenting symptoms and OSS at initial follow-up (R2 < 0.001) or peri-operative change in OSS (R2 < 0.001) or OSS at long-term follow-up (R2 < 0.03). Further analysis at a mean of 42 months (8 to 127) revealed a sustained improvement with a mean OSS of 44 (16 to 48). A good outcome follows an MUA and injection of corticosteroid and local anaesthetic in patients with primary frozen shoulder, independent of the duration of the presenting symptoms, and this improvement is maintained in the long term.

Hidden need for drug treatment services: measuring levels of problematic drug use in the North West of England

BACKGROUND

In the North West of England, data on drug users are routinely collected from a variety of agencies including specialist treatment centres, police and probation services. However, the covert nature of drug use means that alone, these conventional monitoring systems cannot provide the epidemiology required to target and develop drug treatment and prevention initiatives.

METHODS

Utilizing surveillance data and capture-recapture techniques we estimate the rates of problematic drug users by age and sex in five North West health authorities and one local authority.

RESULTS

Analyses show concentrations of problematic drug use in large metropolitan areas (Liverpool and Manchester) with levels as high as 34.5 and 36.5 per 1000 population (ages 15-44), respectively, and, for males, levels exceed 50 per 1000 in three authorities. Patterns of prevalence for those aged 25 and over differed from those in the younger age groups, with disproportionate levels of young users outside metropolitan areas. The proportion of young users already in treatment (21.3 per cent) was lower (older users, 35.3 per cent), with overall proportions in treatment varying between health authorities (range 26.2-46.5 per cent).

CONCLUSION

With a multi-agency approach, established monitoring systems can be used to measure hidden populations of drug users. Estimates of the current populations of such users in the North West of England suggest that planned increases of people in treatment by 100 per cent would fail to accommodate even current level of problematic users. A holistic approach to new initiatives must ensure that the high level of relapse once drug users are discharged are reduced and that the needs of young users are addressed before prolonged treatment is required.

Spinal shrinkage during a seated break and standing break during simulated nursing tasks

Prevalence rates for back pain in nurses are comparable to rates of workers in heavy industry. Spinal loading is one factor thought to be associated with the onset of back problems. Loading can be measured indirectly using precision stadiometry, with changes in stature indicating the magnitude of the loading over time. Ten female subjects completed 4 h of simulated nursing activities on two separate occasions. The two trials were identical except that subjects were asked to sit for a 20-min break in one and stand for a 20-min break in the other trial. Heart rate, discomfort, rating of perceived exertion and spinal shrinkage were recorded at various intervals throughout testing. Spinal shrinkage was significantly less during the seated trial than the standing trial (p<0.05). It is suggested that a seated break during a nursing shift may reduce the potential of suffering back problems resulting from spinal loading.

Effects of activity-rest schedules on physiological strain and spinal load in hospital-based porters

Workers in physically demanding occupations require rest breaks to recover from physiological stress and biomechanical loading. Physiological stress can increase the risk of developing musculoskeletal disorders and repeated loading of the spine may increase the potential for incurring back pain. The aim of the study was to assess the impact of an altered activity-rest schedule on physiological and spinal loading in hospital-based porters. An existing 4-h activity-rest schedule was obtained from observations on eight male porters. This schedule formed the normal trial, which included two 5- and one 15-min breaks. An alternative 4-h schedule was proposed (experimental condition) that had two breaks each of 12.5 min. It was hypothesized that the experimental trial is more effective in promoting recovery from physiological strain and spinal shrinkage than the normal trial, due to the 5-min breaks being insufficient to allow physiological variables to return to resting levels or the intervertebral discs to reabsorb fluid. Ten males performed both test conditions and oxygen uptake VO2, heart rate, minute ventilation VE, perceived exertion and spinal shrinkage were recorded. There were no significant differences in any of the measured variables between the two trials (p > 0.05). Median heart rates were 78 (range 71-93) and 82 (71-90) beats.min(-1) for the normal trial and the experimental trial respectively, indicating that the activity was of low intensity. The light intensity was corroborated by the oxygen uptakes (0.75, range 0.65-0.94 1.min(-1)). Spinal shrinkage occurred to the same extent in the two trials (2.12 +/- 3.16 mm and 2.88 +/- 2.92 mm in the normal trial and the experimental trial respectively). Varying the length and positioning of the rest breaks did not significantly affect the physiological responses or magnitude of spinal shrinkage between the two trials. More physically demanding work than the porters' schedule should induce greater physiological fatigue and spinal shrinkage. The ratio between activity and rest breaks would then become more important.