THE KNEE INJURIES IN SKIING: MECHANISMS AND ASSESSMENT

The purpose of this study is to describe the main mechanisms of knee injuries in skiing, and especially the dominant role of anterior cruciate ligament in these injuries. To complete classical clinical tests of ligamentous laxity and help defining the appropriate time to return to sports after an anterior cruciate ligament reconstruction, accurate 3D kinematic assessment of the weight-bearing knee joint is essential. Current limits of such an assessment are described. Then recent studies of patients with anterior cruciate ligament deficient and reconstructed, using a tibio femoral tracking device specially designed to analyse the kinematics of the knee, are presented

KINEMATIC SYMMETRY IN ROWING: COMPARISON OF FIXED STRETCHER VERSUS FREE-FLOATING ERGOMETER

The purpose of this study was to examine kinematic symmetry of lower and upper limbs when using two kinds of rowing ergometers. Fifteen high-level rowers performed two 15stroke tests at a race rate on two different Rowperfect rowing ergometers. One was fitted up with a fixed stretcher mechanism and the other with a free-floating stretcher mechanism. The tests were carried out in a randomised order. Flexion/extension angles were computed from trajectories of twenty-two markers collected by a motion analysis system. A functional data framework was realised to compare right versus left side angle function curves. These angle curves were validated by bibliographic data. High levels of symmetry were observed for angles of the lower and upper limbs regardless of the mechanism rowed. Shoulder and hip angles for the fixed and the free-floating conditions respectively, were the only exceptions in this regard. The rower's symmetry pointed out by this work allows one-side kinematical analysis of flexion/extension angles

Measuring objective physical activity in people with chronic low back pain using accelerometers: a scoping review

PurposeAccelerometers can be used to objectively measure physical activity. They could be offered to people with chronic low back pain (CLBP) who are encouraged to maintain an active lifestyle. The aim of this study was to examine the use of accelerometers in studies of people with CLBP and to synthesize the main results regarding the measurement of objective physical activity.MethodsA scoping review was conducted following Arksey and O'Malley's framework. Relevant studies were collected from 4 electronic databases (PubMed, Embase, CINHAL, Web of Science) between January 2000 and July 2023. Two reviewers independently screened all studies and extracted data.Results40 publications out of 810 citations were included for analysis. The use of accelerometers in people with CLBP differed across studies; the duration of measurement, physical activity outcomes and models varied, and several limitations of accelerometry were reported. The main results of objective physical activity measures varied and were sometimes contradictory. Thus, they question the validity of measurement methods and provide the opportunity to discuss the objective physical activity of people with CLBP.ConclusionsAccelerometers have the potential to monitor physical performance in people with CLBP; however, important technical limitations must be overcome

Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower Rhône Valley, France

On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower Rhône Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional Cévenne fault system in a context of present-day compressional tectonics

State of the art and current limits of musculo-skeletal models for clinical applications

The prediction of musculo-tendon forces developed during daily living tasks is essential to assess movement control and joint reaction forces, and then provide insight to improve diagnosis and treatment follow-up of neurological and orthopedic disorders. Direct measurement of the musculo-tendon forces is hardly possible and the redundancy inherent in the musculo-skeletal system yields not enough equilibrium equations to compute these forces. Different methods have been proposed to overcome this problem, requiring numerous input parameters, most of them difficult or impossible to adjust to a specific subject. These methods will be exposed and their limits pointed out. Anyway, further development is needed in order that the model-based prediction of musculo-tendon forces can be used for clinical purposes

Sequence Analysis of Grip and Manipulation During Tool Using Tasks: a New Method to Analyze Hand Use Strategies and Examine Human Specificities

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