Advantages and limitations of virtual reality for balance assessment and rehabilitation.

Virtual reality (VR) is now commonly used in many domains because of its ability to provide a standardized, reproducible and controllable environment. In balance assessment, it can be used to control stimuli presented to patients and thus accurately evaluate their progression or compare them to different populations in standardized situations. In balance rehabilitation, VR allows the creation of new generation tools and at the same time the means to assess the efficiency of each parameter of these tools in order to optimize them. Moreover, with the development of low-cost devices, this rehabilitation can be continued at home, making access to these tools much easier, in addition to their entertaining and thus motivating properties. Nevertheless, and even more with low-cost systems, VR has limits that can alter the results of the studies that use it: the latency of the system (the delay cumulated on each step of the process from data acquisition on the patients to multimodal outputs); and distance perception, which tends to be underestimated in VR. After having described why VR is an essential tool for balance assessment and rehabilitation and illustrated this statement with a case study, this review discusses the previous works in the domain with regards to the technological limits of VR.

Upper limb joint kinetic analysis during tennis serve: Assessment of competitive level on efficiency and injury risks.

The aim of this work was to compare the joint kinetics and stroke production efficiency for the shoulder, elbow, and wrist during the serve between professionals and advanced tennis players and to discuss their potential relationship with given overuse injuries. Eleven professional and seven advanced tennis players were studied with an optoelectronic motion analysis system while performing serves. Normalized peak kinetic values of the shoulder, elbow, and wrist joints were calculated using inverse dynamics. To measure serve efficiency, all normalized peak kinetic values were divided by ball velocity. t-tests were used to determine significant differences between the resultant joint kinetics and efficiency values in both groups (advanced vs professional). Shoulder inferior force, shoulder anterior force, shoulder horizontal abduction torque, and elbow medial force were significantly higher in advanced players. Professional players were more efficient than advanced players, as they maximize ball velocity with lower joint kinetics. Since advanced players are subjected to higher joint kinetics, the results suggest that they appeared more susceptible to high risk of shoulder and elbow injuries than professionals, especially during the cocking and deceleration phases of the serve.

Shoulder rotators electro-mechanical properties change with intensive volleyball practice: a pilot study.

This pilot study was designed to assess the incidence of high-level volleyball practice on muscle strength production and muscle activation during internal and external shoulder rotations. Seven professional and seven French amateur league volleyball players performed maximal isometric at three forearm angles, concentric and eccentric isokinetic internal and external shoulder rotations. The torque production and muscle activation levels of PECTORALIS MAJOR and INFRASPINATUS were determined. Few significant differences were found for muscle activation and co-activation between amateur and professional volleyball players during both internal and external rotations. No significant difference in torque production was observed for shoulder internal rotation between professional and amateur volleyball players. Torque production was significantly higher during shoulder external rotation for amateur (46.58+/-2.62 N . m) compared to professional (35.35+/-1.17 N . m) volleyball players relative to isometric contractions, but it was not different during isokinetic efforts. The torque ratios for external/internal rotations were always significantly lower for professional (0.42+/-0.03 pooling isometric and concentric conditions) compared to amateur volleyball players (0.56+/-0.03 pooling isometric and concentric conditions). Those results emphasize that a high level of volleyball practice induces a strong external rotators deficit compared to sports such as swimming, baseball or tennis.

[Education of the adult asthmatic]. / L'éducation de l'adulte asthmatique.

This article aims to examine educational strategies in the context of the overall management of the asthmatic patient. The objectives are analysed from the viewpoints of the both the patient and the health care professionnal. The complexity of the manifestations of asthma and the variability of perception of symptoms require a personalised approach to education. The asthmatic patients, co-operation with their therapeutic management, in particular in matters of compliance, reveals problems common to other chronic conditions. If an agreement can be reached during an exchange of beliefs and points of view, this will lead to the most appropriate choice of therapy. The evaluation of educational strategies has been the subject of many publications and sequential studies must be distinguished from randomised controlled trials. Sequential studies of educational strategies generally include severe asthmatics, previously under-treated. The improvement in measured parameters of morbidity is often striking but it is difficult to separate the true effect of education from that of improved total management, particularly the introduction of preventative treatment. Randomised trials with an "uneducated" control group give more conflicting results. A particular emphasis may be placed on action plans based on monitoring of peak flow and/or symptoms. Finally the inclusion of educational strategies in the training programmes of health care professionnals is now well established and its impact should be evaluated.