Imagerie de la trachée de l'adulte

Imaging of normal and pathologic trachea at the thoracic and cervical levels is described extensively. Beside congenital abnormalities discovered in adulthood, acquired tracheal abnormalities are artificially divided in two subgroups. One group consists of diffuse abnormalities, with all but one diseases associated with a diffuse narrowing of the tracheal lumen. The other group comprises focal abnormalities that lead to tracheal stenoses of various lengths, with a postintubation stenosis as probably the most frequent cause, followed by tumours. The main modality for tracheal imaging is now multidetector-row spiral CT. This technique allows for faster volume coverage and higher spatial and temporal resolution. The improved spatial resolution impacts on both axial images and all reconstructions techniques that have become indispensable for interpretation of a vertical structure such as the trachea. Chest X-ray is no longer the frontline imaging technique. MRI has not yet reached all its potential as compared to CT.     

Variabilité de la fréquence cardiaque en fonction de l'intensité de la pratique physique chez la femme ménopausée

Aim. – Study was to asses the heart rate variability related to the physical practice intensity in post menopausal women.Method. – Time domain measurement of heart rate variability has been realised from the electrocardiogram at rest and during exercice in 3 groups of 6 women : untrained, active and trained. At rest, no significant difference betwen groups appears. But, in the standing position, RR interval and the dispersion around RR interval decrease in trained group only. During submaximal exercise, this dispersion is more elevated in active and trained groups.Conclusion. – Physical practice induces a higher response of sinus node to vagal modulation during standing position and submaximal exercise.     

La résistance cutanée comme indice objectif de la concentration au lancer de poids

Aims – Rules of track and fields events allow subjects to prepare themselves before throwing. As time allocated to preparation was two minutes, it has been reduced to one minute. The aim of this study was to test whether preparation duration decrease had an effect on subjects activation and on performance in shot put.Materiels and methods – Subjects were divided into two groups: beginners and experts. Each subject had to perform seven throws in i) throwing with preparation within the minute allowed ii) without preparation iii) mental representation. Skin resistance tonic level was continuously recorded during the experiment. This autonomic variable is well-known to be a reliable index in predicting activation variations.Results – No difference in performance between the preparation and no-preparation modalities is showed. All the subjects did not reach the same activation during the mental imagery. Activation was shown to be higher in novice than in expert population. However, differences in activation between throwing with and without preparation did not reach the significant threshold. These results suggested that decrease in preparation duration did not affect performance. Subjects were shown to increase their activation themselves rapidly. Performance seems to be mainly dependent upon execution quality rather than reaching an optimal activation level. Motor program of throwing is thought to be rapidly intialised by subjects whatever their practice level.Conclusion – Differences have been evidenced between real trials and mental imagery, both, in movement sequences duration and in activation. If the subjects are not training in the mental imagery, the imagery ability improve with the expertise level.     

Effet de l’intensité de course sur la force de poussée en rugby

Introduction. – The rugby is a discipline requiring, in the same time, strength qualities and a high aerobic capacity for repeating intense exercises over 2 × 40 min.Synthesis of the facts. – Fourteen rugby players performed a maximal progressive test of journey (running) then two sequences of 40 min, respectively, to 60% and 80% of HR_max, interrupted with pushes on a yoke with constraint gauges. At 80% HR_max, the mean scrummaging force (1466 ± 244 N) was lower (P < 0.05) than at 60% HR_max (1523 ± 266 N).Conclusion. – The qualities of specific force are directly affected by the intensity of running. Therefore, there is a need to optimize the aerobic potential notably for the players of the first line directly concerned by the fight.     

Effet de la course d’endurance et/ou des isoflavones sur la masse osseuse de la rate castrée

Aim – To study the effects of endurance running (15 m/min during 20 min/day to 28 m/min during 1 h/d, 6 days/week during 12 weeks, corresponding to 62% of the VO₂ max of the animals) or of a treatment by isoflavones (Soylife 100 : 400 μg j^–1 g^–1 of body weight during 12 weeks), either only or cumulated with running, on the osteopenia induced by castration in adult female rat.Results and discussion – Each one of these two treatment has a protective effect of the bone mineral density at the femoral total, diaphysaire and metaphysaire level. But contrary to what had been reported on the cumulated effects of long term endurance running and of a 17β-estradiol treatment 〚3〛, we did not note any additive effect of these two treatments.     

Dynamique de la locomotion en fauteuil roulant manuel : influences de la masse totale et de sa répartition antéropostérieure sur la résultante des forces de freinage

Purpose. – This study presents a new method for determining the resultant braking force during wheelchair displacement and investigates the respective effects of the level and the distribution of the system’s mass.Method and results. – A three-dimensional accelerometer was fixed directly under the seat of wheelchair and was used to measure the deceleration of the mass-and-wheelchair’s system. Three masses (50, 70 and 90 kg) were laid on a support in 3 positions corresponding to three distributions (10, 40 and 70%) of the system’s total mass upon the front casters. A series of 15 deceleration trials was performed for each of the 9 combinations. Statistical results showed that the system’s deceleration was mainly explained by the mass distribution upon the front casters (92%) and in the least by the system’s total mass (8%).Conclusion. – Considering the fore-and-aft movements of the subject’s centre of mass during wheelchair locomotion, the results of this study let us assume that the resultant braking force does not remain constant along the propulsion cycle. Moreover, the present method could be used to investigate the influence of wheelchair’s adjustments and floor’s characteristics on the resultant braking force.     

Réponses du cortisol et de la testostérone salivaires au cours de la récupération post-compétitive en rugby

Aim. – In order to evaluate the biological repercussions of the post-competitive tiredness state, we measured the progress of the salivary cortisol and testosterone levels in the players of a rugby-team during the week following an international match.Results. – The results reveal a fall of the cortisol levels during the first 4 days following the competition, compared to the values measured at the same hour of a resting day. Conversely, the testosterone levels present an increase during the same period. Consequently, 5 days of recovery are needed for these two biological variables chosen as tiredness markers to return to their basic values.     

Médicaments et performance de la fonction d'équilibration

Introduction – Balance control in some sports discipline can be the aim of the action, and its breaking off can expose to severe trauma.Synthesis of facts – Some drugs' adverse effects can induce lower equilibrium performance, in relation for example with vigilance drop or vestibular ototoxicity. The drug effect site can concern one or more links in the chain (peripheral or central impact). Individual sensitivity is variable, as well as speed of reversibility.Conclusion – Symptoms induced by pathology for which therapy is prescribed are sometimes difficult to distinguish from those induced by therapy itself.