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- Volume 22, Issue 1, 2010
South African Journal of Sports Medicine - Volume 22, Issue 1, 2010
Volumes & issues
Volume 22, Issue 1, 2010
Author Mike LambertSource: South African Journal of Sports Medicine 22 (2010)More Less
Discussions about evidence-based practices in sports medicine often include the question whether practitioners who interact regularly with athletes should be guided by science, or whether scientists should take heed of what these experienced practitioners are doing and then set out to prove whether their approach is beneficial or not.
Effect of body mass and physical activity volume and intensity on pedometry-measured activity energy expenditure in rural black South Africans in the Limpopo Province : original research articleSource: South African Journal of Sports Medicine 22, pp 3 –7 (2010)More Less
Objectives. We developed a novel approach to investigate patterns of pedometry-measured total weekly activity energy expenditure (EEAct) in rural black South Africans in the Limpopo Province.
Design. We analysed 7-day pedometry data in 775 subjects (female: N=508; male: N=267). Variance components models for EEAct were used to estimate the variance explained by body mass (BM), total weekly steps (volume) and estimated intensity (kcal. kg-1.step-1). Univariate General Linear Models, adjusting for age, BM and physical activity (PA) volume, were used to determine if EEAct was primarily affected by volume or intensity.
Results. BM (13.1%), PA intensity (24.4%) and PA volume (56.9%) explained 94.4% of the variance in EEAct. Adjusted EEActdid not differ between sexes (78 kcal.week-1, p =0.2552). There were no significant differences across activity categories (sedentary to very active) for adjusted EEAct (62 - 287 kcal.week-1, p>0.1). Adjusted EEAct for 6 - 7 days of compliance (≥10 000 steps.day-1) differed significantly from 1 - 2 days of compliance (266 - 419 kcal.week-1, p<0.04). Obese (body mass index ≥30 kg.m-2) and normal weight (body mass index 18.5 - 24.9 kg.m-2) women did not differ significantly across activity categories for EEAct (200 - 592 kcal.week-1, p>0.30).
Conclusions. We have highlighted an intensity effect for days of compliance and at very active ambulatory levels (≥12 500 steps. day-1). A volume effect appeared to dominate between sexes, across activity categories and weight-by-activity categories. It is important that post hoc statistical adjustments be made for body mass and PA volume when comparing EEAct across groups.
Author Girish M. RamchandaniSource: South African Journal of Sports Medicine 22, pp 8 –11 (2010)More Less
Objectives. Research examining the phenomenon of home advantage in international multi-sport competitions is limited to the Olympic Games. This paper investigates the prevalence of home advantage in the Commonwealth Games. The paper also explores the relative impact of travel on performance in the Commonwealth Games.
Methods. Home and away performances for all previous host nations were examined using the standardised measure of market share, regarded by recent European studies as the most robust indicator of a nation's sporting performance. For each host nation, the host effect was calculated as the difference between their average home and away performances. Furthermore, the market share values for each host nation were analysed relative to the distance travelled by them (in terms of the number of time zones crossed) in every edition. This exercise was extended to all nations that have sent a team to the Commonwealth Games in the post-war era.
Results. The research found that, with the exception of England, all previous host nations experienced a positive host effect in the Commonwealth Games. Furthermore, for the majority of nations it was found that performance is negatively correlated with distance travelled. In other words, as distance travelled increases, performance deteriorates.
Conclusion. The findings suggest that future host nations of the event can expect to achieve an elevated level of performance when competing on home soil. This may in part be attributable to their athletes not having travel outside their own time zone. Direction for future research is offered.
Evaluation of a school-based physical activity intervention in Alexandra Township : original research articleSource: South African Journal of Sports Medicine 22, pp 12 –19 (2010)More Less
Objectives. Non-communicable diseases and limited participation in school physical education have become increasing concerns in South Africa. In response to these concerns, a school-based physical activity intervention, Healthnutz, was implemented in three primary schools in Alexandra Township, Johannesburg. Evaluation of Healthnutz included assessing its feasibility and acceptability, and short-term changes in learners' physical fitness, knowledge and attitudes.
Methods. To assess feasibility and acceptability, a situational analysis and focus groups with teachers and programme monitors were conducted. Pre-post fitness testing (3-month interval) was conducted with learners, and a questionnaire assessed changes in learners' knowledge, attitudes, self-efficacy, and perceived barriers to physical activity, in control and intervention schools.
Results. At implementation, teachers identified the need for more physical activity in the school environment and were positive about Healthnutz. Follow-up focus group discussions suggested that it was positively impacting teachers, learners and the school in general. Scores for sit and reach (p<0.001), sit ups(p<0.02) and shuttle run (p<0.0001) improved significantly in intervention but not control schools. A significant decrease was observed in learners' perceived external barriers to physical activity(p<0.0001) along with a positive change in learners' self-efficacy for physical activity (p<0.05).
Conclusions. Healthnutz raised awareness of the importance of physical activity in intervention schools. Findings indicate that even limited exposure to a physical activity intervention can lead to a significant improvement in aspects of learners' fitness,knowledge, attitudes and perceptions regarding physical activity.Furthermore, training and support of teachers needs to be non-judgemental and empowering.
Non-steroidal anti-inflammatory drugs in sports medicine : guidelines for practical but sensible use : editor's choiceSource: South African Journal of Sports Medicine 22, pp 20 –22 (2010)More Less
Introduction. Non-steroidal anti-inflammatory drugs (NSAID) are commonly used in sports medicine. NSAID have known antiinflammatory, analgesic, antipyretic and antithrombotic effects, although their in-vivo effects in treating musculoskeletal injuries in humans remain largely unknown. NSAID analgesic action is not significantly greater than paracetamol for musculoskeletal injury but they have a higher risk profile, with side-effects including asthma exacerbation, gastrointestinal and renal side-effects, hypertension and other cardiovascular diseases.
Discussion. The authors recommend an approach to NSAID use in sports medicine whereby simple analgesia is preferentially used when analgesia is the primary desired outcome. However, based both on the current pathophysiological understanding of most injury presentations and the frequency that inflammation may actually be a component of the injury complex, it is premature to suppose that NSAID are not useful to the physician managing sports injuries. The prescribing of NSAID should be cautious and both situation and pathology specific. Both dose and duration minimisation should be prioritised and combined with simple principles of protection, rest, ice, compression, elevation (PRICE), which should allow NSAID-sparing. NSAID use should always be coupled with appropriate physical rehabilitation.
Conclusion. NSAID are probably most useful for treating nerve and soft-tissue impingements, inflammatory arthropathies and tenosynovitis. They are not generally indicated for isolated chronic tendinopathy, or for fractures. The use of NSAID in treating muscle injury is controversial. Conditions in which NSAID use requires more careful assessment include ligament injury, joint injury, osteoarthritis, haematoma and postoperatively.
Source: South African Journal of Sports Medicine 22, pp 24 –27 (2010)More Less
The prescription of eccentric loading is considered as a mainstay of non-operative rehabilitation programmes for mid-substance chronic Achilles tendinopathy. Such exercises have some degree of clinical utility in comparison with concentric training and are often referred to as a strengthening programme. Yet the dose parameters of the eccentric loading do not reflect an optimal strengthening programme and specifically avoid the normal eccentric-concentric coupling typical of the stretch shortening cycle. This manuscript identifies the arguments and counterarguments for why eccentric loading rehabilitation is not an optimal strengthening programme. It is proposed that such exercises reflect a specific stretching programme directed at the passive structures. This has two important clinical implications. Firstly, this reinterpretation of the role of eccentric exercises may direct future research into the underlying mechanisms of tendinopathy and, secondly, it may reinforce the importance of adjunct sports specific strengthening programmes.