Browsing by Author "van Mechelen, Willem"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- ItemOpen AccessThe association between daily steps and health, and the mediating role of body composition: a pedometer-based, cross-sectional study in an employed South African population(BioMed Central, 2015-02-22) Pillay, Julian D; van der Ploeg, Hidde P; Kolbe-Alexander, Tracy L; Proper, Karin I; van Stralen, Maartje; Tomaz, Simone A; van Mechelen, Willem; Lambert, Estelle VBackground: Walking is recognized as an easily accessible mode of physical activity and is therefore supported as a strategy to promote health and well-being. To complement walking, pedometers have been identified as a useful tool for monitoring ambulatory physical activity, typically measuring total steps/day. There is, however, little information concerning dose-response for health outcomes in relation to intensity or duration of sustained steps. We aimed to examine this relationship, along with factors that mediate it, among employed adults. Methods: A convenience sample, recruited from work-site health risk screening (N = 312, 37 ± 9 yrs), wore a pedometer for at least three consecutive days. Steps were classified as “aerobic” (≥100 steps/minute and ≥10 consecutive minutes) or “non-aerobic” (<100 steps/minute and/or <10 consecutive minutes). The data were sub-grouped according to intensity-based categories i.e. “no aerobic activity”, “low aerobic activity” (1-20 minutes/day of aerobic activity) and “high aerobic activity” (≥21 minutes/day of aerobic activity), with the latter used as a proxy for current PA guidelines (150-minutes of moderate-intensity PA per week). Health outcomes included blood pressure, body mass index, percentage body fat, waist circumference, blood cholesterol and blood glucose. Analysis of covariance, adjusting for age, gender and total steps/day were used to compare groups according to volume and intensity-based steps categories. A further analysis compared the mediation effect of body fat estimates (percentage body fat, body mass index and waist circumference) on the association between steps and health outcomes, independently. Results: Average steps/day were 6,574 ± 3,541; total steps/day were inversely associated with most health outcomes in the expected direction (p < 0.05). The “no aerobic activity” group was significantly different from the “low aerobic activity” and “high aerobic activity” in percentage body fat and diastolic blood pressure only (P < 0.05). Percentage body fat emerged as the strongest mediator of the relationship between steps and outcomes, while body mass index showed the least mediation effect. Conclusion: The study provides a presentation of cross-sectional pedometer data that relate to a combination of intensity and volume-based steps/day and its relationship to current guidelines. The integration of volume, intensity and duration of ambulatory physical activity in pedometer-based messages is of emerging relevance.
- ItemOpen AccessLife after the game: consequences of acute spinal cord injuries in South African rugby union players(2019) Badenhorst, Marelise; Lambert, Mike; van Mechelen, Willem; Verhagen, Evert; Brown, JamesThere is a well described association between participation in exercise and sport and the positive effects of physical, social and psychological health. 1,2 Rugby union is a popular team sport across many countries.3 As a team sport, rugby shares these positive benefits. However, the physical demands of the game means that it is also associated with a risk of serious injuries, such as spinal cord injuries (SCIs). 4–6 SCIs have profound long-term effects on every aspect of a person’s life, including their overall quality of life (QoL).7–10 As such, a nationwide injury prevention programme called ‘BokSmart’ was launched in South Africa in 2009, with the aim to reduce and ultimately prevent these injuries.11,12 However, implementing an injury prevention programme in a country with vast socio-economic disparities, such as South Africa, is a difficult task.13 Additionally, optimal acute care after the injury, rehabilitation services and ongoing health maintenance are essential in the management of SCIs and may play a determining role in enhancing and maintaining health and functioning, and therefore QoL.14–16 In South Africa, socio-economic disparities also have a profound effect on healthcare access and the subsequent health of the population. 14 Thus, the additional burden of an injury with permanent consequences may be substantial and is an important issue to investigate. This introductory chapter summarises the literature on the incidence and risk factors for rugby-related SCIs, and the immediate management of these injuries. It also summarises the long-term healthcare issues and overall QoL of players who sustain these injuries and identifies how these problems present both globally and in South Africa. This chapter also provides the overall structure of this PhD-thesis.
- ItemOpen AccessSafer rugby through BokSmart? Evaluation of a nationwide injury prevention programme for rugby union in South Africa(2014) Brown, James Craig; van Mechelen, Willem; Lambert, Mike; Verhagen, Evert; Draper, CatherineIntroduction and objectives: Rugby union ('rugby') is a popular sport that has a high risk of injury. The sport has particular popularity in South Africa with about 500,000 players. Based on concerns about the number of rugby-related catastrophic injuries, the BokSmart nationwide injury prevention programme was launched in July 2009 by South African Rugby Union (SARU). This programme educates coaches and referees on safe techniques during a Rugby Safety Workshop (RSW). To assess real-world injury prevention efforts, researchers have suggested using the six Translating Research into Injury Prevention Practice (TRIPP) stages. Stage 1 and 2 investigate the incidence, severity and aetiology of injuries. Stage 2 investigates the aetiology of injuries. Stage 3 is the introduction of an intervention. Stage 4 is an investigation of the effectiveness of the intervention under ideal conditions. Stages 5 and 6 investigate the real-world implementation of the intervention. Thus, the objective of this thesis is to comprehensively evaluate the BokSmart programme using the TRIPP framework. Methods: TRIPP stages 1 and 2 are investigated in Chapters 2, 3, 4 and 5. Chapter 2 investigates the incidence, severity and aetiology of injuries at four competitive youth tournaments. Chapter 3 used Chapter 2's data to investigate the economic burden of these injuries. Chapter 4 investigates the incidence and severity of catastrophic injuries. Chapter 5 investigates the risk of both general and catastrophic injury specific to the scrum phase of play using the data from Chapters 2 and 4. TRIPP stages 3 and 4 were conducted by SARU and are thus outside the scope of this thesis. TRIPP stages 5 and 6 are investigated in Chapters 6, 7 and 8. Chapter 6 evaluates the effect of BokSmart in on catastrophic injury rates. Chapter 7 evaluates the effect of BokSmart on targeted player behaviours. Chapter 8 uses qualitative methods to investigate coaches and referees' perceptions of BokSmart. Results: Through TRIPP Stages 1 and 2 it was established that South Africa has comparable general and catastrophic injury rates to other countries. Senior players were at significantly (p<0.05) greater risk of suffering a catastrophic injury than younger players. The economic investigation indicated that injury rehabilitation was affected by whether the player had medical insurance or not – this may be unique to South Africa. Through TRIPP stages 5 and 6 BokSmart was associated with a reduction in catastrophic injuries in junior, but not senior players. BokSmart was also associated with a significant improvement in targeted player behaviours. Coaches' perceptions of the programme varied by socioeconomic status (SES). All coaches and referees agreed that the programme was capable of reducing catastrophic injuries in players. However, high SES coaches described difficulties in changing coach and player behaviour, while low SES coaches mentioned their lack of necessary infrastructure as barriers to adoption. There was also negativity about the delivery of BokSmart: coaches and referees felt the course was not practical enough, was too long and should not be compulsory. Conclusions: From BokSmart's perspective, the lack of effectiveness of the programme in senior players should be of concern, considering this age group's greater risk of catastrophic injury. This greater effect in juniors could be explained either by the higher number of players, or greater adoption in this age group. Future research should attempt to elucidate this reason. The barriers and suggestions described by low and high SES coaches and referees should be addressed to optimise the programme's impact. The programme should continue to be evaluated to assess the impact of these suggestions.
- ItemOpen AccessSteps that count! : The development of a pedometer-based health promotion intervention in an employed, health insured South African population(BioMed Central Ltd, 2012) Pillay, Julian; Kolbe-Alexander, Tracy; Proper, Karin; van Mechelen, Willem; Lambert, EstelleBACKGROUND: Physical activity (PA) has been identified as a central component in the promotion of health. PA programs can provide a low cost intervention opportunity, encouraging PA behavioral change while worksites have been shown to be an appropriate setting for implementing such health promotion programs. Along with these trends, there has been an emergence of the use of pedometers as a self-monitoring and motivational aid for PA.This study determines the effectiveness of a worksite health promotion program comprising of a 10-week, pedometer-based intervention ("Steps that Count!"), and individualized email-based feedback to effect PA behavioral change. METHODS: The study is a randomized controlled trial in a worksite setting, using pedometers and individualized email-based feedback to increase steps per day (steps/d). Participant selection will be based on attendance at a corporate wellness event and information obtained, following the completion of a Health Risk Appraisal (HRA), in keeping with inclusion criteria for the study. All participants will, at week 1 (pre-intervention), be provided with a blinded pedometer to assess baseline levels of PA. Participants will be provided with feedback on pedometer data and identify strategies to improve daily PA towards current PA recommendations. Participants will thereafter be randomly assigned to the intervention group (INT) or control group (CTL). The INT will subsequently wear an un-blinded pedometer for 10 consecutive weeks.Individualized feedback messages based on average steps per day, derived from pedometer data (INT) and general supportive/motivational messages (INT+CTL), will be provided via bi-weekly e-mails; blinded pedometer-wear will be conducted at week 12 (post-intervention: INT+CTL).DISCUSSION:The purpose of this paper is to outline the rationale behind, and the development of, an intervention aimed at improving ambulatory PA through pedometer use, combined with regular, individualized, email-based feedback. Pedometer-measured PA and individualized feedback may be a practical and easily applied intervention.TRIAL REGISTRATION:Number: DOH-27-0112-3951