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- Volume 23, Issue 2, 2011
South African Journal of Sports Medicine - Volume 23, Issue 2, 2011
Volumes & issues
Volume 23, Issue 2, 2011
Author Mike LambertSource: South African Journal of Sports Medicine 23 (2011)More Less
A recent thought-provoking paper compared modern lifestyle to the lifestyle of our ancestors, the hunter-gatherers. There is a distinct contrast to the low levels of physical activity in modern times compared with when our ancestors lived as hunter-gatherers, expending large amounts of energy while they obtained food and water, maintained their shelters and escaped from predators. The genes governing the characteristics required for this lifestyle were passed on for approximately 84 000 generations which spanned this period. This, however, is not a long time from an evolutionary perspective. Consider, for example, that the agricultural revolution, during which time food became more readily available, occurred about 350 generations ago, the industrial revolution about seven generations ago and the digital age about two generations ago. Each phase of development placed less emphasis on the necessity for superior physical ability for survival and success. For example, hunter-gatherers covered about 6 - 16 km per day, with daily energy expenditure for physical activity of 800 - 1 200 kcal - this is 3 - 5 times more than that of the average modern-day American. Despite the physical demands of modern-day lifestyles being less than it was several generations ago, the physiological and metabolic characteristics of humans in 2011 are still wired to deal with the physical demands of the hunter-gatherer era, where the norm was to have a high level of energy expenditure. This manifests as modern-day diseases such as heart disease, obesity, diabetes and stroke - diseases which all have a link to low habitual physical activity.
Interventions for chronic low back pain : whole body vibration and spinal stabilisation : original researchSource: South African Journal of Sports Medicine 23, pp 35 –39 (2011)More Less
Objectives. This study explored, described and compared the effects of whole body vibration (WBV) therapy and conventional spinal stabilisation exercises in persons with chronic low back pain (CLBP).
Design. A non-randomised sampling technique was used to delineate the base of volunteers gathered by a combination of accidental and snowball sampling methods. Twenty subjects were randomly assigned into either a WBV or a spinal stabilisation (SS) group. The dependent variables were perception of pain and general functionality, abdominal muscular endurance, spinal muscular endurance and hamstring flexibility. These were measured at the pre-, mid- and post-test assessments. During the 8-week intervention, both groups performed the same spinal stabilisation exercises 3 sessions per week, the difference being the dynamic performance of the conventional land-based SS group compared with the static, isometric performance on the vibration platform. Analysis of variance (ANOVA) determined differences between groups at the pre-, mid- and post-test. Dependent sample t-tests were computed to determine whether the increases/decreases over time were significant within each group. Cohen's d was used to determine the practical significance of results.
Results. There were significant decreases in perception of pain and enhanced performance of functional activity of daily living, increases in abdominal and hamstring flexibility midway through and after the intervention period for both groups. Neither of the two methods of rehabilitation was significantly superior except for spinal muscular endurance in the WBV group after the 8-week intervention. WBV could be considered as an alternative method of exercise intervention for the rehabilitation of CLBP.
Source: South African Journal of Sports Medicine 23, pp 40 –44 (2011)More Less
Objectives. The main purpose of this study was to assess the effect of progressive resistance training on the blood lipid profile in postmenopausal women.
Methods. Twenty-six female participants aged 50 - 75 years were selected from the population of Grahamstown, South Africa. All participants were previously sedentary and possessed at least one lipid profile abnormality but were otherwise healthy. Pretests included a sub-maximal stress test, stature, mass, central and limb girths as well as an oral glucose tolerance test (OGTT) and a total blood lipid profile. Participants took part in a 24-week progressive resistance training programme, consisting of three supervised sessions per week, each lasting 45 minutes. Participants were not permitted to lose more than 10% of initial body mass during the 24-week study. All pre-test measures, excluding the stress test and the OGTT, were repeated every 4 weeks for the duration of the study.
Results. Body mass, body mass index and waist-to-hip ratio did not change. Girth measures at mid-humerus, chest, waist, hip, mid-quadricep and mid-gastrocnemius all decreased significantly (p<0.05). LDL-cholesterol increased significantly over the course of 24 weeks (3.61 mmol.l-1 to 4.07 mmol.l-1), as did total cholesterol (5.81 mmol.l-1 - 6.24 mmol.l-1). Triglyceride concentration remained unchanged and HDL-cholesterol decreased significantly between the pre-test measure (1.55 mmol.l-1) and the measure after 6 months (1.42 mmol.l-1).
Conclusion. The blood lipid profile in a sample of postmenopausal women was not positively affected by a progressive resistance training programme over a 24-week period.
Injury patterns of South African international cricket players over a two-season period : original researchSource: South African Journal of Sports Medicine 23, pp 45 –49 (2011)More Less
Objective. The aim of the study was to determine the incidence and nature of injury patterns of South African international cricket players.
Methods. A questionnaire was completed for each cricketer who presented with an injury during the 2004 - 2005 (S1) and 2005 - 2006 (S2) cricket seasons to determine the anatomical site, month, diagnosis and mechanism of injury.
Results. The results showed that 113 injuries were sustained, with a match exposure time of 1 906 hours for one-day internationals (ODIs) and 5 070 hours for test matches. The injury prevalence was 4% per match, while the incidence of injury was 90 injuries per 10 000 hours of matches. Injuries occurred mostly to the lower limbs, back and trunk, upper limbs and head and neck. The injuries occurred primarily during test matches (43%), practices (20%) and practices and matches (19%). Acute injuries comprised 87% of the injuries. The major injuries during S1 were haematomas (20 %), muscle strains (14%) and other trauma (20%), while during S2 the injuries were primarily muscle strains (16%), other trauma (32%), tendinopathy (10%) and acute sprains (12%). The primary mechanisms of injury occurred when bowling (67%), on impact by the ball (batting - 65%, fielding - 26%) and when sliding for the ball (19%).
Conclusion. The study provided prospective injury incidence and prevalence data for South African cricketers playing at international level over a two-season period, high-lighting the increased injury prevalence for away matches and an increased match injury incidence for test and ODI matches possibly as a result of increased match exposure time.
Source: South African Journal of Sports Medicine 23, pp 50 –56 (2011)More Less
Female athletic participation continues to grow throughout the world. This has many positive effects on health and well-being, but it has also led to a unique set of health problems. The female athlete triad was first described in 1992 by the American College of Sports Medicine, consisting of disordered eating, amenorrhoea and osteoporosis. An updated position stand was released in 2007 that modified the components of the triad to energy availability, menstrual function and bone mineral density. This article reviews the current definitions of the triad components, epidemiology, pathophysiology, diagnosis and treatment. Each of the components of the triad exists on a continuum from healthy to pathological. Low energy availability, from either dietary restriction or increased expenditure, is the factor that leads to the pathological states of menstrual function and bone mineral density. Athletes especially at risk are those in sports requiring leanness or low body weight. Prevention and early recognition of triad disorders is crucial to ensure timely intervention and treatment. Treatment is centered on restoring energy availability to adequate levels (30 kcal.kg-1.d-1) to re-establish normal metabolic functioning. All those who work with female athletes must remain vigilant in the education, recognition and treatment of athletes at risk. Continued research and knowledge of the triad disorders aids the development of prevention and treatment strategies to allow women to continue to enjoy the benefits of regular exercise and physical activity throughout their lives.
Source: South African Journal of Sports Medicine 23, pp 57 –61 (2011)More Less
The world is facing major problems associated with the rapid increase in levels of overweight and obesity. Solving this problem via appropriate modifications to exercise habits and/or diet appears easy, but in practice it is inordinately difficult and only a small percentage manage to maintain their weight loss over the long term. However, a number of strategies can be used to increase the chances of success. Medical doctors, dieticians and other allied health professionals are potentially well placed to provide guidance to those at risk of overweight/obesity. This review is aimed at supporting major initiatives targeting an increase in community physical activity to help reduce the prevalence of overweight/obesity, such as the "Change4Life" campaign in the UK (http://www.nhs.uk/change4life) and the "Exercise is Medicine" campaign in the USA (http://www.exerciseismedicine.org). By providing a concise summary of the evidence-based research that can be easily understood by a wide range of health professionals, this review hopes to provide a useful document that can be used to enhance preventive counselling by promoting appropriate changes in lifestyle that will ultimately increase levels of physical activity, as well as reduce levels of overweight/obesity and other associated chronic hypokinetic conditions.
The introduction of an international model to reduce injuries in Rugby Union in South Africa : commentaryAuthor James Craig BrownSource: South African Journal of Sports Medicine 23, pp 62 –63 (2011)More Less
Regular participation in physical exercise or sport is popular due to the numerous health benefits it offers to the individual. However, these potential benefits need to be offset against the magnitude of risk of injury that participating in the activity may present to the individual. The risk/benefit ratio varies depending on the type of activity. In terms of major male-dominated sports, Rugby Union presents a high risk of overall injury to the player - greater than that of cricket, soccer or even ice hockey. The high incidence of injury in rugby is related to the nature of the game - a field-based team sport that involves multiple contact situations over the 80 minutes of play. Considering the popularity of the sport, with an estimated 92 countries participating worldwide, this injury risk presents a significant global issue. From the inception of the game of Rugby Union, which is speculated to have been between the start of the 1600s and the mid 1800s, the game has been regarded as a violent sport and the formation of the Rugby Football Union in 1871 was necessitated, in part, by the need for laws to reduce this violence.