Creveaux T.,University of Lyon |
Dumas R.,University of Lyon |
Dumas R.,Laboratoire Of Biomecanique Et Mecanique Des Chocs |
Hautier C.,University of Lyon |
And 4 more authors.
Journal of Sports Science and Medicine | Year: 2013
This study aimed at investigating the influence of three rackets on shoulder net joint moments, power and muscle activity during the flat tennis serve under field-conditions. A 6-camera Eagle® motion analysis system, operating at 256 Hz, captured racket and dominant upper limb kinematics of the serve in five tennis players under three racket conditions (A: low mass, high balance and polar moment, B: low three moments of inertia, and C: high mass, swingweight and twistweight). The electromyographic activity of six trunk and arm muscles was simultaneously recorded. Shoulder net joint moments and power were computed by 3D inverse dynamics. The results showed that greater shoulder joint power and internal/external rotation peak moments were found to accelerate and decelerate racket A in comparison with the racket C. Moreover, serving with the racket A resulted in less activity in latissimus dorsi muscle during the acceleration phase, and biceps brachii muscle during the follow-through phase when compared with racket C. These initial findings encourage studying the biomechanical measurements to quantify the loads on the body during play in order to reduce them, and then prevent shoulder injuries. Racket specifications may be a critical point for coaches who train players suffering from shoulder pain and chronic upper limb injuries should be considered in relation to the racket specifications of the players. © Journal of Sports Science and Medicine (2013).
De Seze M.,Bordeaux University Hospital Center |
Randriaminahisoa T.,Laboratoire Of Biomecanique Et Mecanique Des Chocs |
Gaunelle A.,Bordeaux University Hospital Center |
de Korvin G.,Center hospitalier prive Saint Gregoire |
Mazaux J.-M.,Bordeaux University Hospital Center
Annals of Physical and Rehabilitation Medicine | Year: 2013
The objective of this work was to analyze the inter-observer reproducibility of an upright posture designed to bring out the thoracic humps by folding the upper limbs. The effect of this posture on back surface parameters was also compared with two standard radiological postures. A back surface topography was performed on 46 patients (40 girls and 6 boys) with a minimum of 15° Cobb angle on coronal spinal radiographs. Inter-observer reliability was evaluated using the typical error measurement (TEM) and Intraclass Correlation Coefficient (ICC). Variations between postures were assessed using a Student's t test. The inter-observer reproducibility is good enough for the three postures. The proposed posture leads to significant changes in the sagittal plane as well as in the identification of thoracic humps. This study shows the reproducibility of the proposed posture in order to explore the thoracic humps and highlights its relevance to explore scoliosis with back surface topography systems. © 2013 Elsevier Masson SAS.
Patton D.A.,University of New South Wales |
McIntosh A.S.,University of New South Wales |
McIntosh A.S.,Monash University |
Kleiven S.,KTH Royal Institute of Technology |
Frechede B.,Laboratoire Of Biomecanique Et Mecanique Des Chocs
Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology | Year: 2012
Concussion is a prevalent injury in collision and contact sports, but the biomechanics of concussion has mainly been assessed for helmeted head impacts. Concussion and no-injury cases had previously been reconstructed using rigid body simulations from a larger video database of unhelmeted head impact cases from Australian rules football, rugby union and rugby league. The KTH finite element human head model was used to simulate the 27 concussion and 13 no-injury cases, and the maximum principle strain levels in the corpus callosum were evaluated. The rotational kinematics and strain levels were compared to critical strain tolerance curves and reconstructed pedestrian impacts from the literature. It was found that the 5% critical strain tolerance curve equated to a maximum principal strain level of approximately 0.20 and was associated with concussive impacts involving prolonged loss of consciousness. The results suggest rotational kinematics above 4500 rad/s2 and 33 rad/s for peak resultant angular acceleration and maximum change in resultant angular velocity, respectively, as tentative tolerance levels for concussion involving prolonged loss of consciousness. Cases involving short duration or no loss of consciousness had similar rotational kinematics and strain levels in the corpus callosum, suggesting that these injuries are of similar severity. The findings support the hypothesis that sports concussions share some biomechanical characteristics with diffuse axonal injury. © IMechE 2012.
Prat N.,French Armed Forces Institute of Biomedical Research IRBA |
Rongieras F.,Desgenettes Military Academic Hospital |
Rongieras F.,Laboratoire Of Biomecanique Et Mecanique Des Chocs |
Sarron J.-C.,Directorate General of Armaments |
And 2 more authors.
European Journal of Trauma and Emergency Surgery | Year: 2012
The introduction of firearms in the fifteenth century led to the continuous development of bulletproof personal protection. Due to recent industrial progress and the emergence of a new generation of ballistic fibers in the 1960s, the ability of individual ballistic protections to stop projectiles greatly increased. While protective equipment is able to stop increasingly powerful missiles, deformation during the impact can cause potentially lethal nonpenetrating injuries that are grouped under the generic term of behind armor blunt trauma, and the scope and consequences of these are still unclear. This review first summarizes current technical data for modern bulletproof vests, the materials used in them, and the stopping mechanisms they employ. Then it describes recent research into the specific ballistic injury patterns of soldiers wearing body armor, focusing on behind-armor blunt trauma. © 2012 Springer-Verlag.
Pannetier R.,University Claude Bernard Lyon 1 |
Pannetier R.,Laboratoire Of Biomecanique Et Mecanique Des Chocs |
Pannetier R.,Renault S.A. |
Wang X.,University Claude Bernard Lyon 1 |
Wang X.,Laboratoire Of Biomecanique Et Mecanique Des Chocs
Applied Ergonomics | Year: 2014
This paper focuses on the effects of the free pedal position adjustment on clutching movements of the left lower limb as well as on the perceived discomfort. Six automotive clutch pedal configurations were tested by 20 subjects (5 young females, 5 young males, 5 older females, 5 older males) using a multi-adjustable experimental mock-up. Results showed that the pedal position was adjusted to ensure a good starting pedal position allowing a less flexed ankle and avoiding unnecessary leg displacement from the foot rest to the position at start depression. Pedal position adjustment seemed not motivated by reducing joint torque though discomfort ratings were found significantly correlated with knee and ankle torques at the end of depression. The present work also illustrates that the less-constrained motion concept is helpful for a better understanding of people preference and useful for identifying motion-related biomechanical parameters to be considered for defining assessment criteria. © 2014 Elsevier Ltd and The Ergonomics Society.
Desroches G.,University Claude Bernard Lyon 1 |
Desroches G.,INRETS |
Desroches G.,Laboratoire Of Biomecanique Et Mecanique Des Chocs |
Dumas R.,University Claude Bernard Lyon 1 |
And 9 more authors.
Clinical Biomechanics | Year: 2010
Background: Inverse dynamic methods have been widely used to estimate joint loads during manual wheelchair propulsion. However, the interpretation of 3D net joint moments and powers is not always straightforward. It has been suggested to use joint coordinate systems (expression of joint moment on anatomical axes) and the 3D angle between joint moment and angular velocity vectors (propulsion, resistance or stabilization joint configuration) for a better understanding of joint dynamics. Methods: Nine spinal cord injured subjects equipped with reflective markers propelled in a wheelchair with an instrumented wheel. Inverse dynamic results were interpreted using joint coordinate systems, 3D joint power and the 3D angle between the joint moment and joint angular velocity vectors at the three upper limb joints. The 3D angle was used to determine if the joints were predominantly driven (angle close to 0 or 180 degrees) or stabilized (angle close to 90°). Findings: The wrist and elbow joints are mainly in a stabilization configuration (angle close to 90°) with a combination of extension and ulnar deviation moments and an adduction moment respectively. The shoulder is in a propulsion configuration, but close to stabilization (angle hardly below 60°) with a combination of flexion and internal rotation moments. Interpretation: Stabilization configuration at the joints could partly explain the low mechanical efficiency of manual wheelchair propulsion and could give insight about injury risk at the wrist, elbow and shoulder joints. © 2009 Elsevier Ltd. All rights reserved.
Clement J.,École de Technologie Supérieure of Montreal |
Clement J.,Center Hospitalier Of Luniversite Of Montreal Crchum |
Dumas R.,University of Lyon |
Dumas R.,University Claude Bernard Lyon 1 |
And 5 more authors.
Journal of Biomechanics | Year: 2015
Soft tissue artifact (STA) distort marker-based knee kinematics measures and make them difficult to use in clinical practice. None of the current methods designed to compensate for STA is suitable, but multi-body optimization (MBO) has demonstrated encouraging results and can be improved. The goal of this study was to develop and validate the performance of knee joint models, with anatomical and subject-specific kinematic constraints, used in MBO to reduce STA errors. Twenty subjects were recruited: 10 healthy and 10 osteoarthritis (OA) subjects. Subject-specific knee joint models were evaluated by comparing dynamic knee kinematics recorded by a motion capture system (KneeKG™) and optimized with MBO to quasi-static knee kinematics measured by a low-dose, upright, biplanar radiographic imaging system (EOS®). Errors due to STA ranged from 1.6° to 22.4° for knee rotations and from 0.8mm to 14.9mm for knee displacements in healthy and OA subjects. Subject-specific knee joint models were most effective in compensating for STA in terms of abduction-adduction, inter-external rotation and antero-posterior displacement. Root mean square errors with subject-specific knee joint models ranged from 2.2±1.2° to 6.0±3.9° for knee rotations and from 2.4±1.1mm to 4.3±2.4mm for knee displacements in healthy and OA subjects, respectively. Our study shows that MBO can be improved with subject-specific knee joint models, and that the quality of the motion capture calibration is critical. Future investigations should focus on more refined knee joint models to reproduce specific OA knee geometry and physiology. © 2015 Elsevier Ltd.
Philippot R.,Laboratoire Of Physiologie Of Lexercice |
Philippot R.,Jean Monnet University |
Philippot R.,North Hospital |
Boyer B.,Jean Monnet University |
And 6 more authors.
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2012
Purpose: The influence of the medial patellar ligamentous structures on patellar tracking has rarely been studied. Thus the main purpose of this cadaveric biomechanical study was to determine the influence of the medial patellofemoral (MPFL), medial patellomeniscal (MPML) and medial patellotibial (MPTL) ligaments on the three-dimensional patellar tracking during knee flexion. This study was conducted using a validated cadaveric optoelectronic protocol for analysis of patellar kinematics. Methods: For each cadaveric knee study, four successive acquisitions were performed; first was studied patellar tracking in healthy knees, then the junction between MPFL and vastus medialis obliquus (VMO) was sectioned, the MPFL was released at its patellar attachment and finally was released the insertion of the MPML and MPTL. Results: In this study, the MPFL accounts for 50-60% of the medial stabilization forces of the lateral patellar shift during patellar engagement in the femoral trochlea. This work confirm and clarify the role of the MPFL as the primary stabilizer of the patella during the initial 30° of knee flexion. Moreover, this study shows no significant results regarding the stabilizing action of the VMO on the patella during knee flexion. Conclusion: This in vitro study, conducted with an experimental protocol previously validated in the literature, helps quantify the actions of the MPFL, the VMO, and the MPML/MPTL respectively, and identify areas of joint motion where these structures have the most significant influence. This confirms the importance of reconstruction in the treatment of chronic patellar instability. During its reconstruction, care should be taken to adjust the MPFL balance during the initial 20°-30° of flexion. © 2011 Springer-Verlag.
Samson W.,CTC |
Samson W.,University of Lyon |
Samson W.,Laboratoire Of Biomecanique Et Mecanique Des Chocs |
Dohin B.,Jean Monnet University |
And 8 more authors.
Journal of Biomechanics | Year: 2011
Recognition of the changes during gait that occur normally as a part of growth is essential to prevent mislabeling those changes from adult gait as evidence of gait pathology. Currently, in the literature, the definition of a mature age for ankle joint dynamics is controversial (i.e., between 5 and 10 years). Moreover, the mature age of the metatarsophalangeal (MP) joint, which is essential for the functioning of the foot, has not been defined in the literature. Thus, the objective of the present study explored foot mechanics (ankle and MP joints) in young children to define a mature age of foot function.Forty-two healthy children between 1 and 6 years of age and eight adults were measured during gait. The ground reaction force (GRF), the MP and ankle joint angles, moments, powers, and 3D angles between the joint moment and the joint angular velocity vectors (3D angle αM.ω) were processed and compared between four age groups (2, 3.5, 5 and adults).Based on statistical analysis, the MP joint biomechanical parameters were similar between children (older than 2 years) and adults, hinting at a quick maturation of this joint mechanics. The ankle joint parameters and the GRFs (except for the frontal plane) showed an adult-like pattern in 5-year-old children. Some ankle joint parameters, such as the joint power and the 3D angle αM.ω still evolved significantly until 3.5 years. Based on these results, it would appear that foot maturation during gait is fully achieved at 5 years. © 2011 Elsevier Ltd.
PubMed | Laboratoire Of Biomecanique Et Mecanique Des Chocs, Arts et Metiers ParisTech, University of Zaragoza, University of Virginia and 3 more.
Type: | Journal: Accident; analysis and prevention | Year: 2015
Road traffic injuries account for 1.3 million deaths per year world-wide. Mitigating both fatalities and injuries requires a detailed understanding of the tolerance of the human body to external load. To identify research priorities, it is necessary to periodically compare trends in injury tolerance research to the characteristics of injuries occurring in the field. This study sought to perform a systematic review on the last twenty years of experimental injury tolerance research, and to evaluate those results relative to available epidemiologic data. Four hundred and eight experimental injury tolerance studies from 1990-2009 were identified from a reference index of over 68,000 papers. Examined variables included the body regions, ages, and genders studied; and the experimental models used. Most (20%) of the publications studied injury to the spine. There has also been a substantial volume of biomechanical research focused on upper and lower extremity injury, thoracic injury, and injury to the elderly - although these injury types still occur with regularity in the field. In contrast, information on pediatric injury and physiological injury (especially in the central nervous system) remains lacking. Given their frequency of injury in the field, future efforts should also include improving our understanding of tolerances and protection of vulnerable road users (e.g., motorcyclists, pedestrians).