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- Volume 18, Issue 3, 2006
South African Journal of Sports Medicine - Volume 18, Issue 3, 2006
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Volume 18, Issue 3, 2006
Author Mike LambertSource: South African Journal of Sports Medicine 18 (2006)More Less
Extracted from text ... A topic which is receiving much publicity as I write is the banning of 5 skinny models from participating in the Madrid fashion week. Madrid's regional government imposed the rules 'to protect the models as well as teenagers who may develop anorexia as they try to copy underweight catwalk stars'.1 They used a body mass index of 18 as their cutoff value. The 'anti-thin' move has been criticised in Paris and New York, two of the world's leading fashion centres. However, in Italy the move was supported by the mayor who intimated that she would like to apply the same ..
The effect of icepack cooling on skin and muscle temperature at rest and after exercise : original research articleSource: South African Journal of Sports Medicine 18, pp 60 –66 (2006)More Less
<i>Objective.</i> To compare cooling of skin, subcutaneous fat and muscle, produced by an icepack, at rest and after short-duration exhaustive exercise. <br><i>Methods.</i> Eight male subjects were studied. With the subject supine, hypodermic needle-tip thermistors were inserted into the subcutaneous fat and the mid-portion of the left rectus femoris, to a depth of 1 cm plus the adipose thickness at the site, and a temperature probe was placed on the skin overlying the needle tips. A pack of crushed ice was applied for 15 minutes and temperatures were recorded before, during, and for 45 minutes after icepack application. Thereafter, subjects underwent a ramped, treadmill, VO<sub>2max</sub> test, an icepack was applied after temperature probes were inserted into the right leg and measurements were made as before. <BR><i>Results.</i> After the treadmill run, skin (Sk), subcutaneous (SC) and muscle (Ms) temperatures (mean ± standard deviation (SD)) were 0.9 ± 1.3, 1.0 ± 0.7 and 1.3 ± 0.8°C higher than at rest. After 15 minutes of icepack cooling, temperatures fell in the exercised limb by 22.7 ± 1.5°C (Sk), 13.5 ± 4.2°C (SC) and 9.3 ± 5.5°C (Ms) and in the control limb by 20.7 ± 2.9°C (Sk), 11.4 ± 2.0°C (SC) and 8.7 ± 2.6°C (Ms). The reductions in temperature were significant in both the control and exercised limbs. Forty-five minutes after icepack cooling, muscle temperature was still approximately 5°C lower in both the rested and exercised muscle (p < 0.001). Individual variations in response to cooling were noted. <br><i>Conclusions.</i> Cooling of superficial muscle occurs after high-intensity exercise. The degree of cooling is not uniform. This may be due to differences in the sympathetic response to cooling, influencing haemodynamic and thermoregulatory changes after exercise. This needs further investigation.
Author Ian CookSource: South African Journal of Sports Medicine 18, pp 67 –78 (2006)More Less
<i>Objectives.</i> This study addressed (i) the accuracy of measuring ambulatory signals and (ii) the susceptibility to nonambulatory signals, of the Discovery Vitality Pedometer (VT) and the Kellogg's Special K Step Counter (KL) compared with three research-grade pedometers (DW: Yamax DigiWalker SW-401, MTI: MTI Actigraph AM-7164-2.2 , NL: New Lifestyles NL 2000). <br><i>Design.</i> One hundred instruments (20 instruments/brand) were tested at five level walking speeds on a motorised treadmill (3.24, 4.02, 4.80, 5.64, 6.42 km.hr<sup>-1</sup>) and during motor vehicle travel on tarred roads (62.9 km). <br><i>Results.</i> The KL was highly variable across all speeds, while the VT tended to be variable at the lowest speed. The DW, NL and VT significantly underestimated steps below 4.80km.hr<sup>-1</sup> (41 - 94%, p < 0.02) but accuracy improved at speeds <u>></u> 4.80 km.hr<sup>-1</sup> (98 - 102%). The KL displayed the highest variability (60% inter-instrument variance) followed by the VT (10% inter-instrument variance). The research-grade pedometers were the least variable (0 - 1% inter-instrument variance). At 4.80 km.hr<sup>-1</sup>, all research- grade pedometers measured within a 10% margin of error compared with the 90% of VT units and 42% of KL units. The VT was significantly more resistant to nonambulatory signals than the DW (p < 0.01). The KL was the most variable in its response to non-ambulatory signals while the NL was the most consistent. The MTI detected the most non-ambulatory signals (p < 0.05). <br><i>Conclusions.</i> The KL should not be used as a promotional pedometer. The VT achieved the minimum standards required of a promotional pedometer. Further testing is required for longevity, and performance under free-living conditions.
Source: South African Journal of Sports Medicine 18, pp 80 –92 (2006)More Less
<i>Objective.</i> There is little descriptive research on the motion the body displays during the golf swing. The purpose of this research is to review the modern golf swing and compare its motion to the classic golf swing. <br><i>Discussion.</i> The comparison revealed subtle but signifi- cant differences in the backswing and the follow-through positions. The potential implications for power and injury, particularly of the lower back, are discussed. The discussion describes a third swing, the hybrid swing, which is a combination of the classic and modern swing. The hybrid swing may potentially reduce the chances of sustaining a low back injury while still retaining the power of the modern swing. <br><i>Conclusion.</i> The golf swing has evolved over time as a result of a combination of advanced equipment, course design and human experimentation. The hybrid swing is being taught by some golf professionals as a balance between the power-potential of the modern swing and the 'back-friendly' nature of the classic swing, though no studies have so far been conducted on its efficacy. Further investigation into the three golf swings, classic, modern and hybrid, is required to determine which swing is the most effective while also being friendly to the body. Such research will make possible the development programmes aimed at reducing golf injury rates, particularly to the lower back.
Source: South African Journal of Sports Medicine 18, pp 93 –104 (2006)More Less
<i>Objective.</i> The aim of this study was to create an inventory of fitness facilities in South Africa, their location, equipment and services offered, and the demographics, education and training of the staff working in these facilities. <br><i>Design.</i> A total of 750 facilities were identified, and descriptive data were gathered from 442 facilities (59%) with the use of a questionnaire administered telephonically and via the website of the Sports Science Institute of South Africa. <br><i>Setting.</i> The study was initiated by the Sports Science Institute, and the results were presented at the 4th Annual Discovery Vitality Fitness Convention on 4 May 2006. <br><i>Results.</i> Results show that the industry comprises mainly independent facilities (68%). All types of facilities were found to be located mostly within urban areas, and reported providing services to just less than 2% of the South African population. Facilities offer a wide range of equipment and services to their members. Of the fitness-related staff at facilities, the majority were reported to be young (18 - 25 years, 55% of male, and 49% of female staff), and in terms of racial proportions most staff were white (males 40% of total staff and females 33% of total staff). Less than a quarter of fitness-related staff hold university qualifications, and just over 80% of instructors hold quali- fications aligned with the National Qualifications Framework. The importance of education and training of staff was emphasised by respondents. <br><i>Conclusions.</i> This report highlights the widespread value of assessing the fitness industry, particularly within the context of the rise of chronic diseases in South Africa and government initiatives to promote healthy lifestyles.