Previous Page
JOURNAL WATCH Journal Watch
Aircraft cabins are pressurised to maximum effective altitudes of 2440 m, resulting in a significant decline in oxygen saturation in crew and passengers. Forty-five national-level athletes and 18 healthy staff aged 17–70 years were studied on ten long-haul flights. Oxygen saturation and heart rate were measured with a pulse oximeter at sea level before departure, at 3 hours and 7 hours into the flight, and after arrival at sea level. Aircraft cabin pressure and altitude, cabin fraction of inspired oxygen and true altitude were also recorded. Results: Oxygen saturation levels declined significantly after 3 hours and 7 hours (3–4%), compared with sea-level values. There was an associated drop in cabin pressure and fraction
IDENTIFYING SLAP LESIONS: A META-ANALYSIS OF CLINICAL TESTS AND EXERCISE IN
CLINICAL REASONING. Walton DM, Sadi J. Physical Therapy in Sport 2008;9:167-176
An extensive review of international electronic databases was performed to identify all published works of diagnostic accuracy of any test proposed to be diagnostic for superior labral anteroposterior (SLAP) lesions of the shoulder. Results: Twelve studies describing 14 tests were identified. Five tests had been evaluated at least three times in the published literature. Methodological quality scoring was performed and data were extracted. Of the five tests studied, only Yergason’s test demonstrated consistent evidence of significant diagnostic accuracy. Heterogeneity of effect sizes was present for the Crank test.
sportEX comment This is another paper that calls into
question the validity of common tests. As is often the case with such research, the methodological inadequacies in the reporting of the publications are common, and caution must be exercised when drawing inferences from the results of these studies. Having said that, it seems that Yergason’s test is the only one that shows a significant ability to influence clinical decision-making.
EFFECT OF COMMERCIAL AIRLINE TRAVEL ON OXYGEN SATURATION IN ATHLETES. Geertsema C, Williams AB, Dzendrowskyj P, Hanna C. British Journal of Sports Medicine 2008;42:577–581
of inspired oxygen, and an increase in cabin altitude.
sportEX comment Travel isn’t good for athletes. Oxygen saturation declines significantly in athletes during long-haul commercial flights, in response to reduced cabin pressure. This may be relevant for altitude acclimatisation planning by athletes, as
the time spent on the plane should be considered time already spent at altitude, with associated physiological changes. For flights of 10–13 hours in duration, it will be difficult to arrive on the day of competition and avoid the influence of these changes.
RISK FACTORS AND MECHANISMS OF KNEE INJURY IN RUNNERS. Messier SP Legault C, Schoenlank CR, et al. Medicine and Science in Sports and Exercise 2008;40:1873–1879
,
This study aimed to identify behavioural and physiological risk factors that influenced potential knee injury mechanisms, including knee joint forces and knee moments. Participants were 20 adults aged 20–55 years (7 males, 13 females). During the first screening visit, quadriceps and hamstring flexibility was assessed, and Q-angle, height and weight were measured. During the second screening visit, participants completed a series of questionnaires and a gait analysis to calculate knee joint loads. An isokinetic dynamometer was used to measure eccentric and concentric knee extension strength. Results: Body weight, weekly mileage and concentric knee extension strength correlated significantly with tibiofemoral compressive force. Knee extension moment displayed a negative correlation with hamstring flexibility. Both weekly mileage and concentric knee extension strength had significant positive correlations with patellofemoral force.
sportEX comment This was a very small study, considering that an estimated 36 million Americans participate in running each year, with 10.5 million running at least 100 days a year. The results do relate larger knee joint loads to poor hamstring flexibility, greater body weight, greater weekly mileage and greater muscular strength. Most of these risk factors potentially could be modified in order to reduce joint loads and thus lower the risk of injury.
5