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- Volume 18, Issue 1, 2006
South African Journal of Sports Medicine - Volume 18, Issue 1, 2006
Volumes & issues
Volume 18, Issue 1, 2006
Author Mike LambertSource: South African Journal of Sports Medicine 18 (2006)More Less
Extracted from text ... We met our goal of publishing four issues of the Journal in 2005. We will try hard to meet this goal again this year. The factor limiting us will be whether sufficient good-quality papers get passed by our peerreview process. One of the criteria of submitted studies that the reviewers are being asked to scrutinise is the precision of the measurements of the outcome variables. This is particularly important in our field of research. Scientists having to make decisions about changes in physical performance are always faced with the predicament of deciding whether a change is a real, meaningful change, ..
Children in Sport: The psycho-social implications of competitive sport during the middle-childhood yearsAuthor E.M. PetersSource: South African Journal of Sports Medicine 18, pp 2 –7 (2006)More Less
Competition has been a pervasive phenomenon throughout the course of man's history. Not only has our achievement-orientated adult world allowed it to creep into almost every facet with great frequency and magnitude, but it is estimated that in the United States alone, over 17 million children between the ages of 6-16, are presently participating in adult-organised competitive youth sport programmes.
Source: South African Journal of Sports Medicine 18, pp 4 –8 (2006)More Less
<i>Objective.</i> This study investigated the effects of single dosages of the non-steroidal anti-inflammatory drug (NSAID) naproxen, and of the coxib, rofecoxib, on the exercise-induced stress response. <br><i>Design.</i> Eight subjects (age 20.9 <u>+</u> 1.1 years, weight 70.4 <u>+</u> 3.9 kg, height 170.9 <u>+</u> 6.7 cm, body surface area 1.82 <u>+</u> 0.09 m<sup>2</sup>, body mass index 24.1 <u>+</u> 1.3 kg.m<sup>-2</sup>) took part in a double-blind, drug-placebo, cross-over design study. The experimental procedures were performed on 3 occasions on each volunteer, i.e. once on placebo, once on naproxen (single dose of 1 000 mg) and once on rofecoxib (single dose of 50 mg). <br><i>Results.</i> Mean post-exercise cortisol values were signifi-cantly higher than pre-exercise values with the subjects on placebo (<i>p</i> = 0.0365) and rofecoxib (<i>p</i> = 0.0208), but not on naproxen (<i>p</i> = 0.0732). Post-exercise oral temperatures were significantly higher than pre-exercise temperature values on placebo (<i>p</i> = 0.0153) and rofecoxib (<i>p</i> = 0.0424), but not on naproxen (<i>p</i> = 0.5444). <br><i>Conclusion.</i> The results of this study suggest a role for cyclooxygenase-1 (COX-1) in the exercise-induced cortisol and temperature response to exercise.
Source: South African Journal of Sports Medicine 18, pp 10 –12 (2006)More Less
<i>Objective.</i> To determine the incidence of shoulder injuries in competitive swimmers in KwaZulu-Natal, a province in South Africa. <br><i>Design.</i> A cross-sectional survey was conducted. A random sample of 96 swimmers from a pool of 300 swimmers registered with first-division clubs affiliated to the KwaZulu-Natal Aquatics Association participated in the study by informed voluntary consent. Data were gathered using a validated questionnaire. <br><i>Setting.</i> Data were gathered at time trials, races and club meetings. <br><i>Main measures.</i> Variables monitored included the incidence of shoulder injuries, shoulder pain and proportion of overuse injury. <br><i>Results.</i> Seventy-one per cent of the swimmers had shoulder pain and 64% reported injury to the shoulder. Forty-six per cent of the swimmers with pain complained of anterior shoulder pain, while 65% of all injuries were due to overuse. The commonest diagnoses included tendonitis (35%), muscle imbalance (29%), impingement (19%) and other (17%). Sixty-nine per cent of the swimmers swam freestyle which was related to 70% of the injuries. Eighty-one per cent of the injured swimmers sought physiotherapy for the shoulder pain. <br><i>Conclusion.</i> The incidence of shoulder injuries in competitive swimmers is high. This study shows the need for more research into swimming injuries, and the conditioning and rehabilitation of athletes in South Africa.
Author H.H. SchomerSource: South African Journal of Sports Medicine 18, pp 13 –15 (2006)More Less
Stressful experiences like accidents and close misses produce distinct emotional responses in those experiencing them. These short-term stressors make one appreciate the effects longterm stressors must have on one's capacity to adapt and react appropriately and safely to an ever-changing, demanding environment. Acute trauma and injuries are associated with an increased perception of persistent stressful events.
Validity and reliability of the session RPE method for monitoring exercise training intensity : original research articleSource: South African Journal of Sports Medicine 18, pp 14 –17 (2006)More Less
<i>Objective.</i> The Session Rating of Perceived Extertion (RPE) is a method of measuring exercise intensity that may be useful for the quantitative assessment of exercise training programmes. However, there are inadequate data regarding the validity and reliability of the Session RPE method. This study was designed to evaluate both the validity and reliability of the Session RPE method in comparison to objective measures (%HR<sub>peak, </sub> %HR<sub>reserve</sub> and %VO<sub>2peak</sub>) of exercise intensity. <br><i>Methods.</i> Fourteen healthy volunteers (7 male, 7 female) performed 6 randomly ordered 30-minute constant-load exercise bouts at 3 different intensities, with each intensity being repeated. Oxygen consumption (VO<sub>2</sub>) and heart rate (HR) were measured throughout each exercise bout and normalised to maximal values obtained during a preliminary maximal exercise test. Thirty minutes following the conclusion of each exercise bout, the subject rated the global intensity of the bout using a modification of the Category Ratio (CR) (0 - 10) RPE scale. This rating was compared to the mean value of objectively measured exercise intensity across the duration of the bout. <br><i>Results.</i> There were significant non-linear relationships between Session RPE and %VO<sub>2peak</sub> (R<sup>2</sup> = 0.76), %HR<sub>peak</sub> (R<sup>2</sup> = 0.74) and %HR<sub>reserve</sub> (R<sup>2</sup> = 0.71). There were no significant differences between test and retest values of %VO<sub>2peak, </sub> %HR<sub>peak, </sub> %HR<sub>reserve</sub> and Session RPE during the easy (47 v. 47%, 65 v. 66%, 47 v. 48% and 2.0 v. 1.9), moderate (69 v. 70%, 83 v. 84%, 74 v. 75%, and 4.2 v. 4.3) and hard (81 v. 81%, 94 v. 94%, 91 v. 91% and 7.3 v. 7.4) exercise bouts. Correlations between repeated bouts for %VO<sub>2peak</sub> (<i>r</i> = 0.98), %HR<sub>peak</sub> (<i>r</i> = 0.98), %HR<sub>reserve</sub> (<i>r</i> = 0.98) and Session RPE (<i>r</i> = 0.88) were significant and strong. <br><i>Conclusions.</i> The results support the validity and reliability of the Session RPE method of monitoring exercise intensity, although as might be predicted for a subjective method the Session RPE was less precise than the objective measures of exercise training intensity.
Biomechanical factors associated with the risk of knee injury when landing from a jump : review articleSource: South African Journal of Sports Medicine 18, pp 18 –23 (2006)More Less
<i>Objectives.</i> To systematically assess the literature investigating biomechanical knee injury risk factors when an individual lands from a jump. <br><i>Data sources.</i> Four electronic databases were searched for peer-reviewed English journals containing landing biomechanical studies published over 14 years (1990 - 2003). <br><i>Study selection.</i> Publications describing research into knee joint kinetics and/or kinematics when landing from a jump were included. A total of 26 eligible articles met the inclusion criteria. <br><i>Data extraction.</i> A review of the 26 eligible studies was undertaken to describe the key study components including the study aims, sample populations, measurement tools, measurement procedures and knee risk factors. Methodological quality was scored using the Crombie Checklist and PEDro Scale. <br><i>Data synthesis.</i> The methodological quality of the studies reviewed was fair. Information on risk factors was variable. One proposed risk factor, landing with the knee in a relatively more extended position, may increase injury risk. Validity was compromised when the landing action was isolated by studying drop-jumping instead of the whole landing task. Results of reviewed studies were potentially confounded by a number of factors. <br><i>Conclusion.</i> High-level evidence for biomechanical knee injury risk factors when landing from a jump is lacking and it is difficult to draw conclusions regarding knee injury risk factors when landing. However, the published research reviewed provides important information on injury causality and theories to direct future studies. Further research should be directed towards younger populations using valid testing protocols applicable to real life scenarios.
C-reactive protein - biological functions, cardiovascular disease and physical exercise : review articleAuthor S.J. SempleSource: South African Journal of Sports Medicine 18, pp 24 –28 (2006)More Less
C-reactive protein (CRP) is an acute-phase reactant that increases in response to noxious stimuli that inevitably induce cellular and/or tissue injury. The increased synthesis of CRP occurs predominantly in the liver and peaks 24 - 48 hours after the inciting stimulus. CRP forms an integral component of innate immunity and serves primarily to recognise potential pathogens and damaged cells. It facilitates the removal of these cells through opsonisation and activates the complement system. With increasing evidence supporting the classification of artherosclerosis as inflammatory in nature, CRP has received considerable attention as a marker, and in some cases a contributor towards this cardiovascular disease. Traditionally, CRP has been measured within exercise studies to provide evidence that an acute-phase inflammatory response can or has been initiated. Although the elevation in CRP following exercise has largely been attributed to muscle damage, evidence is mounting to contest this premise. Participation in chronic exercise has been associated with a reduced risk of cardiovascular disease. Numerous studies have now shown an inverse relationship between physical activity levels and resting concentrations of CRP. Thus, exercise may prove beneficial in lowering systemic inflammatory markers such as CRP, and consequently contribute towards preventing the progression of inflammatory disorders.