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Summary The human temporomandibular joint (TMJ) is involved in vital functions such as feeding and talking, while its disorder prevalence is reported to be between 5% and 12%. Functional evaluation using quantitative motion analysis tools is interesting in order to better understand normal and abnormal TMJ behavior. But, for the same mandibular displacement, left and right condyles will most certainly give different motion representation: both condyles showing a different shape and volume, being most of the time asymmetric and highly individual. This study performs quantification on relative left and right condyle orientation and position using the spatial location of palpated anatomical landmarks (ALs) and anatomical frames (AFs), on three-dimensional (3D) models created from computerized tomography (CT) performed on 94 mandibles from Universite Libre de Bruxelles bone repository, and magnetic resonance imaging (MRI) performed on 11 living subjects. Our aim was to gather as much data as possible on the morphological aspect of the condyle's orientation asymmetry within the same mandible, in order to better address the difference of motion representation that will be observed for the right and left condyles in further kinematic studies.

The aim of this study was to determine if the results of activities performed using specially developed serious games for physical rehabilitation could be used as an indicator of the natural maturation and decline of motor control in healthy participants. Eighty-one participants (19 children (5–15 years old), 40 adults (18–65 years old) and 22 aged subjects (60–88 years old) participated in this study. Motions performed were recorded using the Kinect sensor. Three different exercises embedded in the games were used to assess upper limb, trunk and lower limb control. The trial duration and accuracy, measures of gross motor function and fine motor control, respectively, were computed for each participant. ANOVA tests shows statistically significant differences between the three groups for duration (53 ± 15, 27 ± 10 and 119 ± 30 s for children, adults and elderly subjects respectively) and accuracy (87 ± 5, 89 ± 10 and 70 ± 8% for children, adults and elderly subjects respectively). The slopes of the curves that approximated the evolution of the performance over various ages are coherent with previous studies about motor control development and physiological decline. The proposed solution, i.e. serious games rehabilitation exercises coupled to motion analysis, seems to be an interesting tool to assess global motor function. Further studies are needed to study the influence of pathologies on the studied parameters.

Several clinical applications rely on accurate guiding information when drilling along the femoral neck (e.g., pin insertion in case of neck fracture). Currently, applications rely on real-time X-ray imaging, which results in irradiation issues for the surgeon conducting the operation. The goal of this paper was to develop an X-ray-free method that would allow for a pathway to be drilled between the lateral aspect of the femoral diaphysis (the so-called piercing point), the femoral neck and the head centres. The method is based on on-the-fly computational predictions relying on a biomechanical database that includes morphological data related to the femoral neck and head and various palpable anatomical landmarks located on the pelvis and the femoral bone. From the spatial location of the anatomical landmarks, scalable multiple regressions allow for the prediction of the most optimal drilling pathway. The method has been entirely validated using in vitro experiments that reproduce surgical conditions. Further, a surgical ancillary prototype that integrates the method of guiding the pin drilling has been developed and used during in vitro and in situ validation using nine hip joints. Pin insertion was controlled after drilling using medical imaging and show successful result for each of the nine trials. The mean accuracy of the estimated hip joint centre and neck orientation was 6.0 ± 2.8mm and 7.1 ± 3.8°, respectively.

Objective Although dual-task paradigm is commonly used in rehabilitation there is, currently, a lack of information about quantitative balance assessment performed in dual-task conditions. The aim of this study is to validate the use of the Nintendo Wii Balance Board (WBB) to assess balance modifications induced by dual-task activity in healthy subjects. Material and Methods Seventy-five healthy participants (37 ± 14 years old, 173± 8 cm, 73± 16 kg, 35 women) participated in this study. Balance was recorded in control situation (baseline) and under two different cognitive tasks (verbal fluency and calculation). Each trial lasted for 60 seconds and were performed with eyes open and closed. Nine parameters were extracted based on center of pressure displacement based on a previously-validated method. ANOVA tests were used to compare the different conditions followed by Bonferroni’s corrections. Protocol was repeated one week after to assess the reproducibility. Results Statistically significant differences were found comparing eyes open and closed situation. Concerning the influence of dual-tasks statistically significant decrease of the balance was observed for both eyes open and closed conditions (increase of the total sway and the speed of displacement). Concerning the reproducibility all parameters shows good to excellent ICC values for the different conditions. Conclusion In this study, we demonstrated the validity of the WBB to detect the effect of the dual-task on balance in healthy subjects. Further studies are needed to determine if such a kind of evaluation can be used in clinics with subjects at risk of falling.

Objective The aim of this work was to determine if scoring mechanisms embedded in cognitive mobile games (CMG) designed for cognitive training are sensitive enough to detect changes in cognitive function induced by various acute respiratory loads in healthy subjects. Material and methods Thirty healthy subjects participated in this study (25 ± 4 years old, 13 women). A set of three brief CMG was used to assess cognitive function (Rush Back, Must Sort, True Color) in control situation and at four different inspiratory loads (through a mouthpiece without resistance and with 10, 50 and 70% of the maximal inspiratory pressure). Results Statistically significant decreases in CMG scores were observed in Rush Back (p = 0.032) and True Color (p = 0.002) when the subjects breathed through the mouthpiece without resistance compared to the control condition. A statistical difference was observed for Must Sort (p = 0.003) between baseline and 10% of Inspiratory Threshold Load (ITL). Significant differences for the three games were observed between the baseline and 50% of ITL and between baseline and 70% of ITL. Conclusion CMG designed for cognitive training are sensitive in detecting transitional changes in cognitive function induced by low, medium and high acute respiratory loads in healthy subjects. This offers interesting new possibilities for the assessment and long-term follow-up of patients suffering from chronic respiratory disease, since this type of assessment could easily be completed independently by patients in their own homes, and could be combined with rehabilitation exercises as an evaluative measure.

There is a link between breathing and balance and posture. When the inspiratory loads are increased by pathologies, there is a decrease of postural control. The increase of the inspiratory load on respiratory muscles is a common feature in various chronic pulmonary pathologies. Consequently, the balance of those patients is likely affected., SCOPUS: ar.j, info:eu-repo/semantics/published

Background Semitendinosus and gracilis muscles whose tendons are used in surgical reconstruction of the anterior cruciate ligament maintain their contractile ability, and a limited decrease of hamstring muscles force is observed postoperatively despite important changes. The goal was to quantify the influence of the myofascial structures on excursions and moment arms of knee muscles to attempt explaining the above-mentioned post-surgical observations. Methods Hamstring harvesting procedures were performed by a senior orthopaedic surgeon on seven lower limbs from fresh-frozen specimens. Femoro-tibial kinematics and tendons excursion were simultaneously recorded at each steps of the surgery. Findings No significant difference was demonstrated for excursions and moment arms after tenotomies and gracilis tendon harvesting ( P ≥ 0.05). The first significant semitendinosus excursion ( P − 4 ) and moment arm ( P − 5 ) decrease was observed after semitendinosus tendon harvesting (46% of the initial excursion). Interpretation Gracilis and semitendinosus myofascial pathway is crucial for force transmission towards the knee joint.

Background Lower limb torsion disorders have been considered as a factor inducing gonarthrosis and the three-dimensional effect of the surgical correction is not well reported yet. This paper reports an in vitro study aiming at quantifying the relationships between experimental femoral torsion disorders and moment arms of thigh muscles. Methods Five unembalmed lower limbs were used and fixed on an experimental jig. Muscles were loaded and 6 Linear Variable Differential Transformers were used to measure tendon excursions. Experimental osteotomies were performed to simulate torsions by steps of 6° up to 18°. Moment arms of the main thigh muscles were estimated by the tendon excursion method during knee flexion. Findings Moment arms of the tensor of fascia latae, the gracilis and the semitendinosus were significantly influenced by experimental conditions while the rectus femoris, the biceps femoris and the semimembranosus did not show modifications. Medial femoral torsion decreased the moment arm of both the gracilis and the semimembranosus. Opposite changes were observed during lateral femoral torsion. The moment arm of the tensor of fascia latae decreased significantly after 30° of knee flexion for 18° of medial femoral torsion. Interpretation Our results showed that medial and lateral femoral torsion disorders induced alterations of the moment arms of the muscles located medially to the knee joint when applied in aligned lower limbs. These results highlight a potential clinical relevance of the effect of femoral torsion alterations on moment arms of muscles of the thigh which may be related, with knee kinematics modifications, to the development of long-term knee disease.

Aging is associated with an increased risk of falling. This lead to a decrease of autonomy and deleterious consequences in case of fall. Rehabilitation exercises must be performed in order to maintain optimal balance. Since a few year video games are used into conventional rehabilitation to motivate patients to regularly do those exercises. Since the motion performed by the patients can be recorded during the games it offers new possibilities to perform evaluation and follow-up of the patients. The aim of this study was to determine if the data collected during specially developed balance rehabilitation exercises using the Microsoft Kinect™ sensor and the Wii Balance Board™ are correlated with the functional and clinical status of elderly patients.

Due to the increase of life expectancy age-related cognitive decline and dementia are a major health issue. Regular evaluation and follow-up must be performed to assess cognitive functions. Regular training (lectures, memory exercises, calculation...) is the best way to preserve cognitive function. Since a few years plenty of video games have been developed to train the brain. Evidence started to emerge about the efficacy of such kind of intervention. However there is a lack of information about the relation between the scores obtained in the games and the cognitive function of the patients. Therefore the aim of this study was to determine if there are correlations between scores obtained from the games and cognitive function. Twenty 18-aged controls and 16 patients with cognitive impairments (MMSE >20) participated in this study. Scores obtained in 8 mini-games were correlated with MMSE and the revised version of the Addenbrooke's Cognitive Evaluation (ACER). Mean correlation between the 8 games and the MMSE is 0.62 and 0.65 for the ACE-R. Those results seems to indicate that cognitive video games could be used to follow evolution of cognitive function of aged people with and without cognitive impairment at least when MMSE is > 20/30.

Quadric surface fitting of joint surface areas is often performed to allow further processing of joint component size, location and orientation (pose), or even to determine soft tissue wrapping by collision detection and muscle moment arm evaluation. This study aimed to determine, for the femoral bone, if the position of its morphological joint centers and the shape morphology could be approximated using regression methods with satisfactory accuracy from a limited amount of palpable anatomical landmarks found on the femoral bone surface. The main aim of this paper is the description of the pipeline allowing on one hand the data collection and database storage of femoral bone characteristics, and on the other hand the determination of regression relationships from the available database. The femoral bone components analyzed in this study included the diaphysis, all joint surfaces (shape, location and orientation of the head, condyles and femoro-patellar surface) and their respective spatial relationships (e.g., cervico-diaphyseal angle, cervico-bicondylar angle, intercondylar angle, etc.). A total of 36 morphological characteristics are presented and can be estimated by regression method in in-vivo applications from the spatial location of 3 anatomical landmarks (lateral epicondyle, medial epicondyle and greater trochanter) located on the individual under investigation. The method does not require any a-priori knowledge on the functional aspect of the joint. In-vivo and in-vitro validations have been performed using data collected from medical imaging by virtual palpation and data collected directly on a volunteer using manual palpation through soft tissue. The prediction accuracy for most of the 36 femoral characteristics determined from virtual palpation was satisfactory, mean (SD) distance and orientation errors were 2.7(2.5) mm and 6.8(2.7)°, respectively. Manual palpation data allowed good accuracy for most femoral features, mean (SD) distance and orientation errors were 4.5(5.2) mm and 7.5(5.3)°, respectively. Only the in-vivo location estimation of the femoral head was worse (position error=23.2 mm). In conclusion, results seem to show that the method allows in-vivo femoral joint shape prediction and could be used for further development (e.g., surface collision, muscle wrapping, muscle moment arm estimation, joint surface dimensions, etc.) in gait analysis-related applications.

0, info:eu-repo/semantics/published

Accurate spatial location of joint center (JC) is a key issue in motion analysis since JC locations are used to define standardized anatomical frames, in which results are represented. Accurate and reproducible JC location is important for data comparison and data exchange. This paper presents a method for JC locations based on the multiple regression algorithms without preliminary assumption on the behavior of the joint-of-interest. Regression equations were obtained from manually palpable ALs on each bone-of-interest. Results are presented for all joint surfaces found on the clavicle, scapula and humeral bone. Mean accuracy errors on the JC locations obtained on dry bones were 5.2+/-2.5 mm for the humeral head, 2.5+/-1.1 mm for the humeral trochlea, 2.3+/-0.9 mm for the humeral capitulum, 8.2+/-3.9 mm for the scapula glenoid cavity, 7.2+/-3.2 mm for the scapular aspect of the acromio-clavicular joint, 3.5+/-1.8mm for the clavicular aspect of the sternoclavicular joint and 3.2+/-1.4 mm for the clavicular aspect of the acromio-clavicular joint. In-vitro and in-vivo validation accuracy was 5.3 and 8.5mm, respectively, for the humeral head center location. Regression coefficients for joint radius dimension and joint surface orientation were also processed and reported in this paper.

Many studies show good clinical results after proximal row carpectomy. Some biomechanical consequences are documented, but to our knowledge muscle moment arm variations have not previously been quantified.In five fresh-frozen wrist, kinematics and tendon excursions were measured using a 3D electrogoniometer and Linear Variable Differential Transformers (SOLARTRON Inc., AMETEK Advanced Measurement Technology, Inc, 801 South Illinois Avenue, Oak Ridge, TN 37831-2011, USA), respectively, in three conditions: intact wrist, after posterior capsulotomy and after proximal row carpectomy. Mean pivot point, defined as the point whose sum of the squared distances to the helical axes is minimum, wrist range of motion and mean moment arms were measured during dorso-palmar flexion, radioulnar deviation and circumduction movements.No alteration of the range of motion was observed. On the other hand, the mean pivot point shifted proximally (6.8-9.1mm) after proximal row carpectomy (p0.05) for all motions tested and most muscle moment arms decreased significantly after proximal row carpectomy.The results of this study allow a better understanding of the biomechanical effects of this procedure. The important moment arm reduction and pivot point displacement suggest modifications of joint biomechanical parameters which could influence the functional outcome of PRC.

IF: 0.355, IFmax: 1.404 (Anatomical Record), info:eu-repo/semantics/published

Biomedical science and its allied disciplines are entering a new era in which computational methods and technologies are poised to play a prevalent role in supporting collaborative investigation of the human body. Within Europe, this has its focus in the virtual physiological human (VPH), which is an evolving entity that has emerged from the EuroPhysiome initiative and the strategy for the EuroPhysiome (STEP) consortium. The VPH is intended to be a solution to common infrastructure needs for physiome projects across the globe, providing a unifying architecture that facilitates integration and prediction, ultimately creating a framework capable of describing Homo sapiens in silico. The routine reliance of the biomedical industry, biomedical research and clinical practice on information technology (IT) highlights the importance of a tailor-made and robust IT infrastructure, but numerous challenges need to be addressed if the VPH is to become a mature technological reality. Appropriate investment will reap considerable rewards, since it is anticipated that the VPH will influence all sectors of society, with implications predominantly for improved healthcare, improved competitiveness in industry and greater understanding of (patho)physiological processes. This paper considers issues pertinent to the development of the VPH, highlighted by the work of the STEP consortium., Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published

Anatomical relationships between the radial nerve, the deltoid muscle insertions and several bony landmarks have been investigated to assess the feasibility of surgical transfer of the deltoid transfer during humeral osteotomy. Eleven embalmed human specimens were dissected. Each specimen included the whole thorax, both shoulders and upper limbs. Spatial position of the radial nerve along the radial groove, the deltoid muscle, and several anatomical landmarks was digitised using a three-dimensional (3D) digitiser. Sixteen distances and one angle characterizing the relationships between the path of the radial nerve and the landmarks were processed. Results showed that the average distance between the emergence of the radial nerve from the lateral intermuscular septum and the most distal insertion point of the deltoid muscle on the humeral bone shaft was 47.6 +/- 18.5 mm. The angle between a line extending from the entry of the radial nerve into the radial sulcus and its point of emergence (REN-REM line), and on the other hand a line running from the radial emergence and the deltoid muscle tip (REM-DELTIP line) was in average 23.5 +/- 6.7 degrees .The length of four lines running perpendicular to REM-DELTIP and crossing each quarter of the REN-REM line were interpolated. The length of these four lines was, from proximal to distal, 31.3 +/- 11.5 mm; 23.0 +/- 7.8 mm; 16.5 +/- 6.2 mm; and 7.6 +/- 2.6 mm, respectively. These results described in a quantitative way the path of the radial nerve in respect to the humeral bone and the deltoid muscle. These data will be used for further development of a humeral osteotomy protocol taking into account the spatial position of the radial nerve to orientate safely the surgical tools used to cut the humeral shaft., info:eu-repo/semantics/published

A multimodal visualization software, called the Data Manager (DM), has been developed to increase interdisciplinary communication around the topic of visualization and modeling of various aspects of the human anatomy. Numerous tools used in Radiology are integrated in the interface that runs on standard personal computers. The available tools, combined to hierarchical data management and custom layouts, allow analyzing of medical imaging data using advanced features outside radiological premises (for example, for patient review, conference presentation or tutorial preparation). The system is free, and based on an open-source software development architecture, and therefore updates of the system for custom applications are possible.

The paper describes a method in which two data-collecting systems, medical imaging and electrogoniometry, are combined to allow the accurate and simultaneous modeling of both the spatial kinematics and the morphological surface of a particular joint. The joint of interest (JOI) is attached to a Plexiglas jig that includes four metallic markers defining a local reference system (R(GONIO)) for the kinematics data. Volumetric data of the JOI and the R(GONIO) markers are collected from medical imaging. The spatial location and orientation of the markers in the global reference system (R(CT)) of the medical-imaging environment are obtained by applying object-recognition and classification methods on the image dataset. Segmentation and 3D isosurfacing of the JOI are performed to produce a 3D model including two anatomical objects-the proximal and distal JOI segments. After imaging, one end of a custom-made 3D electrogoniometer is attached to the distal segment of the JOI, and the other end is placed at the R(GONIO) origin; the JOI is displaced and the spatial kinematics data is recorded by the goniometer. After recording, data registration from R(GONIO) to R(CT) occurred prior to simulation. Data analysis was performed using both joint coordinate system (JCS) and instantaneous helical axis (IHA).Finally, the 3D joint model is simulated in real time using the experimental kinematics data. The system is integrated into a computer graphics interface, allowing free manipulation of the 3D scene. The overall accuracy of the method has been validated with two other kinematics data collection methods including a 3D digitizer and interpolation of the kinematics data from discrete positions obtained from medical imaging. Validation has been performed on both superior and inferior radio-ulna joints (i.e. prono-supination motion). Maximal RMS error was 1 degrees and 1.2mm on the helical axis rotation and translation, respectively. Prono-supination of the forearm showed a total rotation of 132 degrees for 0.8mm of translation. The method reproducibility using JCS parameters was in average 1 degrees (maximal deviation=2 degrees ) for rotation, and 1mm (maximal deviation=2mm) for translation. In vitro experiments have been performed on both knee joint and ankle joint. Averaged JCS parameters for the knee were 109 degrees, 17 degrees and 4 degrees for flexion, internal rotation and abduction, respectively. Averaged maximal translation values for the knee were 12, 3 and 4mm posteriorly, medially and proximally, respectively. Averaged JCS parameters for the ankle were 43 degrees, 9 degrees and 3 degrees for plantarflexion, adduction and internal rotation, respectively. Averaged maximal translation values for the ankle were 4, 2 and 1mm anteriorly, medially and proximally, respectively.

ObjectiveThe purpose of the present study was a 2D-semiautomated morphometric analysis of craniofacial growth in nuclear magnetic resonance imaged (NMRI) mouse embryos.MethodsThe NMRI mouse embryos were exposed in utero to either a single dose of 2 Gy X-irradiation on day 9 of gestation (113 embryos) or to 1.5 mg methyl-triazene administered orally to their pregnant mothers on gestational day 10.5 (124 embryos). An additional group of 108 embryos was used as controls. Digitized pictures of embryos from gestational days 14 to 17 were taken in lateral right view using a video system. Landmarks were located and digitized for computerized analysis of growth changes in relation to developmental stages of the face.ResultsThe results revealed that the snout of control embryos lengthens during the developmental period considered. The snout of embryos previously submitted to methyl-triazene displayed micrognathia, and all treated fetuses exhibited macroscopic signs of microcephaly with a reduced mandible. The snouts of irradiated embryos appeared shortened at the 14-day stage and continued to shorten as development proceeded. A shortening of the midface was detected macroscopically in 83% of the cases.ConclusionThe results of this morphometric analysis enabled us to trace the developmental progression of the induced dysmorphosis and to assess the differences compared with normal development.

The fixation sites of two antibodies, HNK-1-anti-leu 7 and anti- HNK-1/N-CAM, were studied during visceral cephalogenesis in the rat. The labelling patterns of both antibodies were different. Anti-leu 7 staining was restricted to trunk neural crest cells, the peripheral nervous system, myotomes and premuscular cells, the eye rudiment and the olfactory vesicle. On the other hand, anti- HNK-1/N-CAM extended to the otocyst, several epithelia (including tooth germs) and precartilages. Anti-HNK-1/N-CAM staining of somites and cranial nerve ganglia was more precocious than anti-leu 7 labelling. We conclude that both antibodies, despite several common sites labelling, display quite different immunological properties, and that the expression "HNK-1" positive has no absolute significance.

INTRODUCTION Analysis of 3D-kinematics of the carpal bones faces several difficulties, due to their small size, complicated shape and uneasy access. Among the problems encountered, the definition of coordinate frames has to be valid and reliable. The ISB recommendations concerning the carpal joint coordinate systems have [1] recently been criticized [2]. In the past, several approaches have been proposed in studies using medical imaging to study carpal kinematics. These include the use of anatomical landmarks [3], inertial axes [2,4], or surface registration [5,6]. The aim of this study was to compare kinematics data obtained using anatomical landmarks and inertial axes and to validate them using implanted landmarks.

INTRODUCTION Calibration of anatomical landmarks (ALs) [1] is a key procedure for the determination of anatomical features related to the bones of a particular subject. Such ALs can then be used for the definition of local joint reference frames or registration with other data for advanced visualization or modeling [2]. In all cases the accuracy of the AL location will depend on the system used for such digitizing. The accuracy is directly proportional to the quality of the final registration and the repeatability of the measurements (a key element in a clinical setting, e.g., for patient follow-up) [2]. Standards procedures for AL location include setting of reflective markers on the subject’s skin at relevant spots, leading to relatively high errors because of skin artifacts. A more accurate method is the use of calibrated wands in order to better locate the ALs. Unfortunately, the latter method is time consuming and the protocol requires, 1 first to palpate the relevant AL with the finger pulp; -2 then to remove the finger from the AL; 3 to set the extremity of the wand on the AL; 4 to eventually digitize the AL location. The transition between steps 2 and 3 is prone to introduce errors since the palpating sensitive finger leaves the point of interest to be replaced by a non-sensitive instrument. The aim of this undergoing study is to develop a protocol able to calibrate a customized palpation system made of the palpating finger of the individual performing the palpation (i.e., the “palpator”) and a technical frame attached on this finger. Results will be presented during the conference.

The use of video games in rehabilitation is becoming more popular to clinicians. These games are embedded in off-the-shelf commercial entertainment applications or especially-developed for clinical purposes. Treatment of cerebral palsy (CP) children is a challenging task for clinicians. Lack of motivation and progress monitoring are two important factors clinicians need to deal with. The use of serious games (SG), sometimes referred to as Virtual Rehabilitation (VR), could therefore be an interesting adjuvant to conventional treatment for these patients. This is however a new discipline and many scientific issues remain to be solved. The aim of this paper is to describe available conventional treatment for CP children together with the level of evidence of each approach. A systematic review of the use of SG in rehabilitation is then conducted. 31 papers (7 randomized clinical trials, 16 cohort studies and 8 single-cases studies) were selected and analyzed, and their level of evidence compared to the conventional treatment. These studies reported outcomes for 352 patients. In summary, this review shows that it is difficult to compare those studies despite the large amount of patients. This is due to the lack of standardization in patient rehabilitation strategy and to the use of various clinical scales and scores. This non-standardization in patient follow-up between previously-published works make evidence-based conclusions difficult to obtain in order to support these techniques objectively. The use of SG for rehabilitation purposes currently meets similar issues. This paper proposes standardization strategies in order to improve treatment comparison and SG use in rehabilitation.

Low Back Pain (LBP) is one of the most frequent musculoskeletal pathology. There is, currently, a lack of affordable and easy to use assessment tools for these patients. For the moment such kind of evaluation tools are limited to gait analysis centers. Management of LBP included physiotherapy and exercises that patients need to perform at-home. The use of serious games (games with a primary purpose other than pure entertainment) in the treatment of LBP patients is becoming more and more popular. Therefore, the aim of this paper was to develop and validate a biomechanical analysis of trunk motion during rehabilitation exercises. Results obtained with the Kinect™ sensor were compared with results obtained using state-of-the-art optoelectronic device. Different scores have also been developed in order to assess, in a clinically relevant way, the motions performed by the subjects. Those scores could be used to ensure that at-home exercises that need to be performed by the patients during conventional rehabilitation program or during telerehabilitation are done correctly

Cerebral Palsy (CP) leads to various clinical signs mainly induced by spasticity. Among these ones impaired balance and posture are very common. Traditional physical therapy exercise programs are focusing on this aspect but it is difficult to motivate patients to regularly perform these exercises. Specially developed serious games (SG) could therefore be an interesting option to motivate children to perform specific exercise for balance improvement. This paper presents a feasibility study including 10 CP children. Patients received 4 sessions of SG included into conventional therapy. Trunk control and balance were assessed using Trunk Control Motor Scale (TCMS) before and after intervention. Children presented a significant improvement in TCMS after interventions (37,6 (8.7) and 39.6 (9.5) before and after intervention respectively, p=0.04). SG could therefore be an interesting option to integrate in the conventional treatment of CP children.

Although stiffness and strength of lower limb bones have been investigated in the past, information is not complete. While the femur has been extensively investigated, little information is available about the strain distribution in the tibia, and the fibula has not been tested in vitro. This study aimed at improving the understanding of the biomechanics of lower limb bones by: (i) measuring the stiffness and strain distributions of the different low limb bones; (ii) assessing the effect of viscoelasticity in whole bones within a physiological range of strain-rates; (iii) assessing the difference in the behaviour in relation to opposite directions of bending and torsion. The structural stiffness and strain distribution of paired femurs, tibias and fibulas from two donors were measured. Each region investigated of each bone was instrumented with 8-16 triaxial strain gauges (over 600 grids in total). Each bone was subjected to 6-12 different loading configurations. Tests were replicated at two different loading speeds covering the physiological range of strain-rates. Viscoelasticity did not have any pronounced effect on the structural stiffness and strain distribution, in the physiological range of loading rates explored in this study. The stiffness and strain distribution varied greatly between bone segments, but also between directions of loading. Different stiffness and strain distributions were observed when opposite directions of torque or opposite directions of bending (in the same plane) were applied. To our knowledge, this study represents the most extensive collection of whole-bone biomechanical properties of lower limb bones.

Skeletal forces are fundamental information in predicting the risk of bone fracture. The neuromotor control system can drive muscle forces with various task- and health-dependent strategies but current modelling techniques provide a single optimal solution of the muscle load sharing problem. The aim of the present work was to study the variability of the hip load magnitude due to sub-optimal neuromotor control strategies using a subject-specific musculoskeletal model. The model was generated from computed tomography (CT) and dissection data from a single cadaver. Gait kinematics, ground forces and electromyographic (EMG) signals were recorded on a body-matched volunteer. Model results were validated by comparing the traditional optimisation solution with the published hip load measurements and the recorded EMG signals. The solution space of the instantaneous equilibrium problem during the first hip load peak resulted in 10(5) dynamically equivalent configurations of the neuromotor control. The hip load magnitude was computed and expressed in multiples of the body weight (BW). Sensitivity of the hip load boundaries to the uncertainty on the muscle tetanic stress (TMS) was also addressed. The optimal neuromotor control induced a hip load magnitude of 3.3 BW. Sub-optimal neuromotor controls induced a hip load magnitude up to 8.93 BW. Reducing TMS from the maximum to the minimum the lower boundary of the hip load magnitude varied moderately whereas the upper boundary varied considerably from 4.26 to 8.93 BW. Further studies are necessary to assess how far the neuromotor control can degrade from the optimal activation pattern and to understand which sub-optimal controls are clinically plausible. However we can consider the possibility that sub-optimal activations of the muscular system play a role in spontaneous fractures not associated with falls.

Background The use of formalin fixed bone tissue is often avoided because of its assumed influence on the mechanical properties of bone. Fixed bone tissue would minimise biological risks and eliminate preservation issues for long duration experimental tests. This study aimed to determine the short- and long-term effects of embalming, using a solution with 4% formalin concentration, on the mechanical properties of human cortical bone. Methods Three-millimetre cylindrical specimens of human cortical bone were extracted from two femoral diaphyses and divided in four groups. The first group was used as control, the remaining three groups were left in the embalming solution for 48 h, 4 week, and 8 week, respectively. Compressive mechanical properties, hardness and ash density were assessed. The last was used to check the homogeneity among the four groups. Findings No significant differences were found among the four groups in yield stress, ultimate stress and hardness. The specimens stored for 8 week in the embalming solution had significant lower Young’s modulus (−24%), higher yield strain (+20%) and ultimate strain (+53%) compared to the other groups. Interpretation On a short-term perspective, embalming did not affect the compressive mechanical properties, nor hardness of human cortical bone, whereas a long-term preservation (8 week) did significantly affect Young’s modulus, yield strain and ultimate strain in compression. Preserving bone segments for up to 4 week in an embalming solution with low formalin concentration seems to be an interesting alternative when collecting and/or managing fresh or fresh-frozen bone segments for biomechanical experiments is not possible.