Subjective perceptions of load carriage on the head and back in Xhosa women

The purpose of this study was to compare the subjective perceptual responses to both head-loading and back-loading in a group of Xhosa women. Thirty two women were divided into three groups based on their experience of head-loading and walked on a treadmill on two occasions, head-loading and back-loading, at a self selected walking speed for four minutes with a variety of loads until pain or discomfort caused the test to be terminated or a load of 70% body mass was successfully carried. After each workload there was a one minute rest period during which the women indicated feelings of pain or discomfort in particular areas of the body via visual analogue scales. At the end of each test the women were asked to complete further questionnaires relating to pain and discomfort and on completion of the second test were also asked to compare the two loading conditions. Finally the women were interviewed to establish their history of load carriage and associated pain and discomfort. The data indicate that whilst back-loading was generally associated with more areas of discomfort than head-loading, the pain and discomfort in the neck associated with head-loading was the predominant factor in the termination of tests and that this was independent of head-loading experience. This early termination meant that, on average, the women could carry greater loads on their backs than on their heads. The study suggests that further work needs to be carried out to establish viable alternatives to head-loading for rural dwellers in Africa

No 'free ride' for African women:a comparison of head-loading versus back-loading among Xhosa women

Although contrasting evidence exists in the literature as to the economy of head-loading, there is a notion that head-loading is an extremely economical method of load carriage. This has become known as the ‘free ride’ hypothesis and, although untested, it is widely accepted. The purpose of this study was to test the ‘free ride’ hypothesis for head-load carriage among African women by comparing the relative economy of head-loading and back-loading. Twenty-four Xhosa women walked on a level treadmill, attempting to carry loads of between 10% and 70% of their body mass (BM) using both a backpack and a head basket. All 24 women carried at least 25% of their BM in both conditions. The relative economy of load carriage was calculated for loads of 10% to 25% of BM. Results indicated that the ‘free ride’ was not a generalisable phenomenon, with both methods realising economy scores close to unity (1.04 ± 0.19 and 0.97 ± 0.15 for head-loading and back-loading, respectively). The results did, however, reveal significant individual differences in economy scores and it is suggested that analysis of such individual differences in future may well be instructive in understanding mechanisms associated with greater economy in load carriage

A kinetic comparison of back-loading and head-loading in Xhosa women

The purpose of this study was to compare the kinetic responses associated with ground reaction force measurements to both head-loading and back-loading in a group of Xhosa women. Altogether, 16 women were divided into two groups based on their experience of head-loading. They walked over a force plate in three conditions: unloaded or carrying 20 kg in either a backpack or on their head. The most striking finding was that there was no difference in kinetic response to head-loading as a consequence of previous experience. Considering the differences between the load carriage methods, most changes were consistent with increasing load. Head-loading was, however, associated with a shorter contact time, smaller thrust maximum and greater vertical force minimum than back-loading. Both loading conditions differed from unloaded walking for a number of temporal variables associated with the ground contact phase, e.g. vertical impact peak was delayed whilst vertical thrust maximum occurred earlier. Statement of Relevance: Consideration of the kinetics of head and back load carriage in African women is important from a health and safety perspective, providing an understanding of the mechanical adaptations associated with both forms of load carriage for a group of people for whom such load carriage is a daily necessity

The Extra Load Index as a method for comparing the relative economy of load carriage systems

The Extra Load Index (ELI) has been proposed as a suitable method of assessing the relative economy of load carriage systems. The purpose of this study was to determine, based on empirical evidence, that the ELI can accommodate variations in both body composition and added load. In total, 30 women walked carrying loads of up to 70% body mass at self-selected walking speeds whilst expired air was collected. In addition, each of the women had body composition assessed via dual energy X-ray absorptiometry. Results show that the ELI is independent of body composition variables, the magnitude of additional loads and the speed of progression. Consequently, it is suggested that it represents an appropriate method of comparing load carriage systems in both scientific and commercial arenas. Statement of Relevance:This paper demonstrates that ELI is independent of body composition, added load and speed and is therefore an appropriate method to generalise comparisons of load carriage systems. It has the advantage of being easily understood by manufacturers and consumers whilst retaining appropriate scientific precision

A comparison of the physiological consequences of head-loading and back-loading for African and European women

The aim is to quantify the physiological cost of head-load carriage and to examine the ‘free ride’ hypothesis for head-load carriage in groups of women differing in their experience of head-loading. Twenty-four Xhosa women [13 experienced head-loaders (EXP), 11 with no experience of head-loading (NON)] attempted to carry loads of up to 70% of body mass on both their heads and backs whilst walking on a treadmill at a self-selected walking speed. Expired air was collected throughout. In a second study nine women, members of the British Territorial Army, carried similar loads, again at a self-selected speed. Maximum load carried was greater for the back than the head (54.7 ± 15.1 vs. 40.8 ± 13.2% BM, P <0.0005). Considering study one, head-loading required a greater oxygen rate than back-loading (10.1 ± 2.6 vs. 8.8 ± 2.3 ml kg bodymass−1 min−1, P = 0.043, for loads 10–25% BM) regardless of previous head-loading experience (P = 0.333). Percentage changes in oxygen consumption associated with head-loading were greater than the proportional load added in both studies but were smaller than the added load for the lighter loads carried on the back in study 1. All other physiological variables were consistent with changes in oxygen consumption. The data provides no support for the ‘free ride’ hypothesis for head-loading although there is some evidence of energy saving mechanisms for back-loading at low speed/load combinations. Investigating the large individual variation in response may help in identifying combinations of factors that contribute to improved economy

A pilot investigation of load-carrying on the head and bone mineral density in premenopausal, black African women

Although the influence of weight bearing activity on bone mass has been widely investigated in white women, few studies have been conducted in black, African populations. We investigated bone mineral density (BMD) in black South African women, with and without a history of load-carrying on the head. We also investigated whether load carrying may offer protection against low BMD in users of injectable progestin contraception (IPC). Participants were 32 black, South African women (22.4±3.2 yrs). Load carrying history was determined by questionnaire and interview and participants were grouped as load carriers (LC; n=18) or non load carriers (NLC; n=14). Ten women were using IPC and 6 were load-carriers. Total body (TB), lumbar spine (LS) and total hip (H) BMD were measured by dual energy X-ray absorptiometry. There were no differences in BMD between LC and NLC, and after controlling for age and BMI using two-tailed partial correlations. IPC users had lower BMD at all sites compared to non IPC users (p<0.05) and there were no associations between load carrying and BMD in this group. When IPC users were excluded from analysis, LC had higher LS BMD than NLC (p<0.005). Correlations were found between the weight of load carried and LS BMD (r=0.743, p<0.005), and between years of load carrying and LS and TB BMD (r=0.563, r=0.538 respectively; both p<0.05). Load carrying on the head may offer osteogenic benefits to the spine but these benefits did not appear in women using IPC

COVID-19 Knowledge, attitude and prevention practice in southwest Nigeria

To assess COVID-19 knowledge, attitude and prevention practice as well as the associated factors among people living in Southwest, Nigeria. This was an online cross-sectional study among dwellers of southwest Nigeria. Data were collected online with kobo toolbox and analyzed using descriptive statistics, test of independence and binary logistic regression. Of the 286 study participants, 96.1% had good knowledge, 99.3% had positive attitude towards control of COVID-19, while 77.3% had good practices for prevention of the virus. Majority of the participants (86.9%) had tertiary education, 11.3% were 40years or older. Age and education were independently associated with COVID-19 prevention practice. After adjustment for some selected socio-demographic factors, only age of 10 – 19 years (OR: 3.83, CI: 1.05, 14), age 20-29 years (OR: 2.99, CI: 1.18 -7.55), and 30 -39 years (OR: 4.35, CI: 1.49-12.67) were more likely to have good practice of COVID-19 prevention compared to age >=40 years. The result revealed a high prevalence of good practices, and majority had good knowledge of COVID-19 and positive attitude towards control of COVID-19. Age and education were identified to be associated with practice of COVID-19 prevention. While further exploration revealed that elders (>=40years) were not likely to have good practice of COVID-19 prevention. We deduced that good practice of COVID-19 prevention was high in southwest Nigeria but notably low among elders and those who attained below tertiary education in southwest Nigeria. However, people of older age and poor education should be given much attention for proper enlightening and prevention strategies in this pandemic

Mathematical modelling of the fluid dynamics involved in colonic mixing with applications to drug delivery

Within the pharmaceutical industry there is current interest in the proximal colon as a site for drug delivery. Segmental contractions of the smooth colonic muscle are the most prevalent type; these promote the mixing of material within the lumen, which in turn aids absorption. Few physical or theoretical models have been developed to assist with the understanding of dosage form behaviour within the colon. We model the colon as a cylindrical pipe, whose boundary represents the circular muscle layer. Assuming the boundary is axisymmetric and that the contractions may be modelled by a standing wave of small amplitude, we employ a perturbation expansion to describe the behaviour of both one and two layer fluid flow using various rheological models. Utilising the results and Lagrangian particle tracking we create a model of drug delivery which analyses the proportion, by volume, of a drug reaching the colonic epithelium, discovering that the segmental contractions of the colon lead to effective mixing of the fluid. We investigate the results of varying the fluid rheology and contractile properties, finding that the amplitude of contraction has the largest effect on the proportion of particles absorbed. The results prove themselves robust to variation in contractile frequency, fluid viscosity and ratio between radius and wavelength, which is promising in terms of consistent drug delivery across a range of physiological states

Carrying the torch - can student teachers contribute to the survival of design and technology in the primary curriculum?

Not since the statutory introduction of design and technology as a foundation subject at Key Stages 1 and 2 in the National Curriculum for England and Wales in 1990 has there been more pressure on its survival in primary schools than at present. The ‘deregulation’ of the non-core curriculum to make way for the introduction of National Literacy and Numeracy Strategies has, according to Rogers and Davies (1999), had a devastating effect upon the classroom time it is currently allotted in many schools. The situation is, if anything, more acute in primary initial teacher training (ITT), where the impact of a series of government circulars, culminating in Department for Education and Employment (DfEE) Circular 4/98, has reduced total course provision in design and technology for the majority of students to a few hours. Although some hope may be on the horizon – in the shape of the new rationale for the subject in the Secretary of State’s proposals for Curriculum 2000, and the positive exemplification provided by the national Scheme of Work (QCA/DATA, 1999) – the situation is currently very difficult for primary student teachers required to teach design and technology during their school experience. Unless these opportunities are made available, a generation of primary student teachers may emerge from training with little or no experience of classroom or college design and technology, thus risking undoing much of the good work in teacher development undertaken during the last decade. It may then be too late to undo the damage done to the concept of a ‘balanced curriculum’ in which design and technology has a significant part to play

Measuring violence against children:A COSMIN systematic review of the psychometric properties of child and adolescent self-report measures

Research on violence against children (VAC) requires meaningful, valid, and reliable self-report by children. Many instruments have been used globally and decisions to select suitable measures are complex. This review identifies child and adolescent self-report measures that are most likely to yield valid, reliable, and comparable data in this field. A systematic review (PROSPERO: CRD4201706) was conducted using the 2018 Consensus-based Standards for the selection of health Measurement Instrument (COSMIN) criteria. Six electronic databases and gray literature were searched. Manuscripts published in English and describing the development and psychometric qualities of child/adolescent self-report instruments were included. Thirty-nine original instruments and 13 adaptations were identified in 124 studies. The quality of evidence ranged from “very low” to “high” depending on the measure and the psychometric properties assessed. Most measures were not widely used, and some have been applied in many settings despite limited evidence of their psychometric rigor. Few studies assessed content validity, particularly with children. The ACE, CTQ, CTS-PC, CECA, ICAST, and JVQ have the best psychometric properties. An overview of items measuring frequency, onset, duration, perpetrators, and locations is provided as well as an assessment of the practicalities for administration to help researchers select the instrument best suited for their research questions. This comprehensive review shows the strengths and weaknesses of VAC research instruments. Six measures that have sufficient psychometric properties are recommended for use in research, with the caveat that extensive piloting is carried out to ensure sufficient content validity for the local context and population.</p