Étude épidémiologique de la scoliose chez les enfants roumains scolarisés

The long-term clinical history of this patient from 4 to 22 years highlights the links between severe cerebral palsy and progressive and fixed vertebral deformations.The risk factors in this patient were asymmetrical motor disease and a weakness of righting reactions observed in non ambulatory subjects.Hip dysplasia and painful stiffness of both knees required surgical palliation at the age of 11 and 13 years.Progressive spinal deformation affected both lateral curvatures. The first occurred early, producing a left dorsal curvature with a short radius, the second compensatory curvature affected the the dorsal and lumbar vertebrae producing a right sided curvature with a large radius related to pelvic imbalance.The graphic presentation of the spinal curvatures revealed rapid worsening at puberty.Arthrodesis from D2 to the sacrum was performed at 14.10 years.Given the stiffness of the trunk, it can be expected that the independence of this young adult who lives alone in a flat seated in an electrical wheelchair with assistance for special needs and works half time in the community, may be compromised in the future.

Effets de la gymnastique d'entretien sur la consommation de médicaments psychotropes par les seniors

Objectives. – To evaluate the effect of a regular physical activity on the use of hypnotics, anxiolytics and antidepressants among elderly.Main facts. – Survey by self-administered questionnaires in 12 months of interval. The response rate was 55% (1709 females and 192 males, mean age 68.4 ± 5.6 years). Physical activity: they practiced soft gymnastics for 11.3 years on average, at a rate of 1.7 ± 1.0 sessions (2.0 ± 1.4 hours) per week, but 152 subjects had begun this activity. Psychotropic drugs: during the last 30 days, 13.9% of our respondents said that they have taken hypnotics, 5.6% had used anxiolytics and 4.7% had used antidepressants. The average percentage of hypnotics users is higher at those which has just begun (23.8% vs 13.2%, P < 0,05) and it drops after one or two years of regular practice (18.2% after one-two years, 13.1% after three-nine years, 11.0% after ten years, P < 0.05). Of the elderly who began the activity, 24.3% said that they have used hypnotics or anxiolytics during the past 30 days. One year later, they were only 5.9% (P < 0.05). The effects are less convincing for the antidepressants.Conclusions. – Regular practice of soft gymnastics could decrease the use of certain psychotropic drugs among elderly.     

Cinétique de la consommation d’oxygène chez le cycliste amateur

Aims

Study was to analyze the relationship between oxygen uptake and power output in amateur cyclists before and after threshold corresponding to a blood lactate concentration of 4 mmol/l.

Methods

We evaluated 109 subjects and they were divided according to age, cycling speciality, level and period. Each subject performed an incremental exercise test (50 W per 3 min) until exhaustion on an electromagnetically braked cycloergometer. Gas exchange data were continuously analyzed and recorded using an automated breath by breath system. Mean values of oxygen uptake were taken during the last minute of each stage in order to build and calculate the regression equations.

Results

The total sample presents an oxygen–kinetic deflection after lactate threshold, with the slope before threshold significantly higher (P < 0.001) than the slope after threshold. This indicates an absence of linearity. Considering the level, the slope and intercept before threshold of the national group presented significantly lower values than regional cyclists. For speciality, the slope before threshold is significantly lower in mountain bike group compared to road. Slope's analyse before and after lactate threshold could present complementary criteria for a good discrimination in comparison with classic concepts used during an incremental exhaustive test.     

Relation entre le lancer de balle et la force isocinétique des rotateurs d'épaule chez le handballeur de haut niveau

Objectives. – The aim of this study was to calculate correlations between isokinetic torque of the internal and external dominant shoulder rotators and ball velocity in high-level handball players.Synthesis of facts. – Internal and external shoulder rotators were examined in twenty-one national level handball male players on the concentric mode action at 60, and 120°/second. External rotators were examined on the eccentric action at 60 and 120°/second. Concentric ratio ERcon/IRcon and mixed ratio ERecc/IRcon were calculated. Ball velocity was measured in three types of throw: throw in seated position, standing throw and throw with three meter running jump. After statistical analysis using the Spearman correlation coefficient, no correlation was found between strength of internal and external shoulder rotators and ball velocity. The relationship between ball velocity of the throw in seating position and concentric and mixed ratios at 60 and 120°/second was significant (P < 0.01).Conclusion. – Peak torque of internal and external rotators of the dominant shoulder was not a good indicator of throwing velocity.     

Effets de la dominance oculaire sur la coordination œil–main dans les duels sportifs

Duel sports, such as fencing, boxing and table-tennis, like some “face-to-face” individuals in team sports, give rise to extremely fast visuo-motor interactions. These situations, characterized by a high level of uncertainty in space and time, require a very high level of visual attention from protagonists. Investigations carried out in these sports reveal, at the highest level of world ranking, an over-representation of manual left-handers, the majority of them having a right ocular dominance. Right-handers having a left dominant eye are also represented at a relatively high-rate. Experimental tasks with spatio-temporal uncertainty implemented in the laboratory have made it possible to confirm a visuo-motor advantage, in response time, in subjects having an eye–hand crossed laterality.     

L'aptitude physique: étude comparée chez l'homme et la femme

Comparison of male and female performance trends in athletics and swimming over the last decade shows that women tend to improve their results less rapidly than men. Does this divergence reflect unequal physical capacities? Measuring performance implies the determination of numerous (biological, psychological, sociological) elements. For most authors, physical capacities are decisive in explaining performance levels, as expressed by energetic and biochemical factors. The latter are analysed in this study in order to compare performances in both sexes. Energy expenditure may be assessed through the study of maximum aerobic power and aerobic endurance. During tests which required a significant amount of aerobic power, female were observed to be lower than male performances. These differences may be explained by the lower maximal oxygen uptake (O₂ max) in women. Absolute O₂ max values, expressed in 1·min⁻¹ are typically 30 to 50% higher in men than in women. Using the relative expression of O₂ max, in ml of oxygen per kg of body weight, the apparent sex difference in maximal aerobic power is reduced to approximately 20%. Thus, part of the sex difference in O₂ max is related to the difference in body size and weight. One factor known to influence O₂ max is relative body fat. If O₂ max is expressed relative to fat-free weight, the sex difference in O₂ max is further reduced and, in some cases, ceases to exist. A smaller heart size and a lower hemoglobin concentration are two factors which are proposed as a possible hypothesis to explain this variation. The sex differential in O₂ max between trained men and women was less than for untrained subjects. On the other hand, during exercise involving moderate speed, women displayed better endurance properties than men. This observation indicates that females depend upon aerobic energy turnover and fat combustion to a larger extent than males. A higher lipid contribution to energy metabolism was explained in women compared to men via the lower values of respiratory exchange ratios obtained in women for oxygen uptake values below 75 to 80% of maximal oxygen uptake.The biochemical component takes into consideration the strength characteristics are produced by muscle and the conditions under which thus strength is manifested, assessed through efficiency study. Men are usually stronger than women because they have more muscle mass. However, when muscular strength is expressed relative to lean body mass or to cross-sectional area of muscle, sexual differences are reduced significantly. Signifaicant differences in gross energy expenditure are apparent between men and women but when expressed in relation to body weight, the difference in energy cost is decreased. These differences are also dependent upon activity and training level.In general, women have a significantly lower capacity to perform physical work than men. The effects of physical fitness training do not alter these differences.     

Modèles mathématiques et physiologiques de la performance humaine

Summary

Introduction

In this century, empirical and bioenergetic endurance modelling (i.e., the relationship between time and velocity) have been proposed to predict and explain performance over short and long distances, in running especially. The purpose of this article is to present an historical review of these modelling and applying some of them to middle- and long- distance running.

Current knowledge and key points

The limit of each of these models is considered as the inter-individual variability of time to exhaustion (time limit) at the maximal oxygen consumption. In the same manner, none of them take into account the oxygen slow component, which appeared for supra-lactate threshold exercise.

Future prospects and projects

In the future, the oxygen slow component and variability of time to exhaustion at the maximal oxygen consumption should be taken into account to better individualize this bioenergetic profile via the endurance model.     

Effets du repas précompétitif sur la perception de l'effort et sur la glycémie lors d'un exercice de pédalage

The first purpose of the present study was to investigate the effect of three different preexercise meals on perceived exertion and glycaemia during a one-hour bicycle exercise at 80% VO₂ max. The second purpose of this study was to determine the relationship between glycaemia and perceived exertion. Eight athletes (age: 24.6 ± 2.7 years, weight: 78.0 ±6.8 kg, height: 182.6 ± 9.9 cm) completed three assessment sessions, each being preceeded by one of the following meals, ingested 3 h before exercise: 400 mL of water, 400 mL of water and 75 g of glucose, and 100 mL of water and 375 g of potatoes. The subjects 'perceived exertion were measured at times 6, 15, 30, 45, 60 min and glycaemia at 0, 30, 60 min of the exercise. The results showed that perceived exertion (RPE and ETL) of each meal increased as a function of time (P <- 0.05) whereas glycaemia did not differ except for the glucose meal between 30 min and 1 h(P < 0.02). There was no significant difference in ratings of perceived exertion among any meal whereas glycaemia was different between the three conditions only at the beginning and the middle of the exercises (P < 0.04 and P < 0.02, respectively). Moreover, the vectorial angles between the variables ofperceived exertion and the glycaemia are close to 90 °. These results would suggest that perceived exertion does not seem to be affected by the three preexercise meals used in our study. Perceived exertion is not correlated to glycaemia changes during one-hour high intensity exercise. The results would, therefore, suggest that glycaemia is not a contributor signal of perceived exertion in this study. It seems that physiological factors other than glycaemia may have mediated the perceptual intensity at exhaustion. The respiratory-metabolic signals of exertion which are most pronounced at high relative exercise intensity are suggested to influence the perceptual signal of exertion.     

Augmentation de la fréquence d’apparition de l’hypoxémie induite par l’exercice chez des rameurs de haut-niveau

Objectifs. – Évaluer la fréquence d’apparition de l’hypoxémie induite par l’exercice (HIE) chez un groupe de rameurs de haut-niveau.Méthodes. – Sept rameurs de haut-niveau ont participé à l’étude (19,14 ± 1,3 ans). Les sujets ont effectué une épreuve d’effort à charge croissante sur un rameur ergométrique lors de laquelle les échanges gazeux et la saturation de l’hémoglobine en oxygène (SpO₂) ont été mesurés.Résultats. – Les sujets avaient une VO₂max de 61,68 ± 1,65 ml/min par kilogramme. Tous ont présenté une HIE avec des chutes de SpO₂ comprises entre 5 et 11 %. Cette chute était significative dès 70 % VO₂max. Le volume d’entraînement réduit des athlètes testés par rapport aux autres athlètes endurants semble indiquer que le phénomène est indépendant du volume d’entraînement.Conclusion. – Cette étude a permis de mettre en évidence que 100 % des rameurs de haut-niveau présentaient une HIE. La limitation ventilatoire et l’importante masse musculaire mise en jeu spécifiques à l’aviron seraient les hypothèses explicatives.Aim. – To access the frequency of exercise-induced hypoxemia (EIH) in elite oarsmen.Method. – Seven elite oarsmen participated (19.14 ± 1.3 year) in this study. Subjects performed an incremental exercise testing on a rowing ergometer. Gas exchanges and pulse oxymetric saturation in oxygen (SpO₂) were measured during exercise.Results. – Subjects exhibited a mean of VO₂max of 61.68 ± 1.65 ml min^–1 kg^–1. All rowers showed an EIH with a SpO₂ ranging between 5% and 11%. This SpO₂ fall was significant from 70% VO₂max. The reduced training volume of our athletes compared with others endurance trained athletes seems indicate that phenomenon is not dependent of training volume.Conclusion. – This study showed that 100% of elite oarsmen exhibit EIH. Mechanical limitation in ventilation and great muscle mass involved in rowing could be the explicative hypothesis.