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1.
Int J Surg ; 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39037734

RESUMEN

INTRODUCTION: Patients with high-grade gliomas often have severe brain edema. Goal-directed fluid management protects neurological function, but whether reduces postoperative brain edema remains unknown. METHODS: Patients having elective resection of supratentorial malignant gliomas were randomly assigned to goal-directed versus routine fluid management. Patients assigned to goal-directed management group were given 3 mL kg-1 hydroxyethyl starch solution when stroke volume variation exceeded 15% for 5 minutes. Fluid was managed per routine by attending anesthesiologists in reference patients. The primary outcome was cerebral edema volume after surgery as assessed by computerized tomography. RESULTS: A total of 480 eligible patients were randomly assigned to the goal-directed (n = 240) or the routine fluid management group (n = 240). The amounts of crystalloid (5.4 vs. 7.0 ml kg-1 hour-1, P < 0.001), colloid (1.1 vs. 1.7 ml kg-1 hour-1, P < 0.001), and overall fluid balance (0.3 vs. 1.9 ml kg-1 hour-1, P < 0.001) were significantly lower in goal-directed fluid management. There was no significant difference in postoperative brain edema volume between groups (36.0 cm3 vs. 38.9 cm3, mean difference: 0.18cm3, 95% CI: -5.7 to 5.9). Goal-directed patients had lower intraoperative dural tension (risk ratio: 0.63, 95% CI: 0.50 to 0.80, P < 0.001). There was no significant difference in Karnofsky Performance Status between the two groups at 30 days after surgery. CONCLUSIONS: Goal-directed fluid therapy substantially reduced intravenous fluid volumes, but did not reduce postoperative brain edema in patients having brain tumor resections.

2.
J Clin Med ; 11(24)2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36555951

RESUMEN

This study examined the effects of minimal and conventional running footwear on medial tibiofemoral cartilage mechanics and longitudinal failure probability. The current investigation examined twenty males who habitually ran in minimal footwear and 20 males who habitually ran in conventional footwear. Kinematic data during overground running were collected using a motion-capture system and ground reaction forces using a force plate. Medial tibiofemoral loading was examined using musculoskeletal simulation and cartilage failure probability via probabilistic modelling. In habitual minimal footwear users, peak medial tibiofemoral cartilage force, stress and strain were significantly greater in conventional (force = 7.43 BW, stress = 5.12 MPa and strain = 0.30), compared to minimal footwear (force = 7.11 BW, stress 4.65 MPa and strain = 0.28), though no significant differences in these parameters were evident in non-habitual minimal footwear users (conventional: force = 7.50 BW, stress = 5.05 MPa and strain = 0.30; minimal: force = 7.40 BW, stress = 4.77 MPa and strain = 0.29). However, in both habitual and non-habitual minimal footwear users, the probability of medial tibiofemoral cartilage failure was significantly greater in conventional (habitual = 47.19% and non-habitual = 50.00%) compared to minimal footwear (habitual = 33.18% and non-habitual = 32.81%) users. The observations from this investigation show that compared to minimal footwear, conventional footwear appears to have a negative influence on medial tibiofemoral cartilage health.

3.
Trials ; 23(1): 950, 2022 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-36401274

RESUMEN

INTRODUCTION: Brain edema is the most frequent postoperative complication after brain tumor resection, especially in patients with high-grade glioma. However, the effect of SVV-based goal-directed fluid therapy (GDFT) on postoperative brain edema and the prognosis remain unclear. METHODS AND ANALYSIS: This is a prospective, randomized, double-blinded, parallel-controlled trial aiming to observe whether stroke volume variation (SVV)-based GDFT could improve the postoperative brain edema in patients undergoing supratentorial high-grade gliomas compared with traditional fluid therapy. The patient will be given 3 ml/kg hydroxyethyl starch solution when the SVV is greater than 15% continuously for more than 5 min intraoperatively. The primary outcome will be postoperative cerebral edema volume on brain CT within 24 h. ETHICS AND DISSEMINATION: This trial has been registered at ClinicalTrials.gov (NCT03323580) and approved by the Ethics Committee of Beijing Tiantan Hospital, Capital Medical University (reference number: KY2017-067-02). The findings will be disseminated in peer-reviewed journals and presented at national or international conferences relevant to the subject fields. TRIAL REGISTRATION: ClinicalTrials.gov NCT03323580 (First posted: October 27, 2017; Last update posted: February 11, 2022).


Asunto(s)
Edema Encefálico , Fluidoterapia , Glioma , Humanos , Edema Encefálico/prevención & control , Fluidoterapia/métodos , Glioma/cirugía , Objetivos , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto
4.
Front Aging Neurosci ; 14: 909551, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35912078

RESUMEN

Background: Age-induced sarcopenia negatively affects walking stability and increases the risk of falls, which is the leading cause of accidental death in the elderly. Objective: This study aimed to analyze and contrast body composition and gait characteristics in those with sarcopenia in relation to healthy controls to shed some light on the prevention of falls in elderly patients with sarcopenia. Materials and Methods: In this study, 68 community dwellers were scanned by the Hologic QDR-4500A Dual-energy X-ray absorptiometry (DXA). The appendicular lean mass index (ALMI) results were used to distinguish the normal participants from those with sarcopenia: 24 in the sarcopenia group, and 44 into the normal group. The participants were asked to undergo gait analysis on a plantar pressure measurement system. Statistical analysis was conducted to contrast both groups' gait and butterfly parameters from their gait test, and then a gait forward dynamics method was performed to quantify the analysis for both groups. Results: The ALMI of the female was not related to their age (r = 0.06) while that of the male was weakly related (r = 0.17). Body mass index (BMI) from both groups was normal, although with a statistically greater BMI from the normal group compared with sarcopenia (p < 0.001). Greater values and significant differences were found in step length and stride length from the normal elderly group (p < 0.01), and so was the length of the gait line and single support line (p < 0.05). Gait forward dynamics analysis results showed no motor neural or musculoskeletal disorders in their gait performance from the sarcopenia group. Conclusion: For the elderly, age did not largely affect the ALMI, BMI, or T-score, but BMI and ALMI were strongly correlated. In this study, significant differences were found in certain gait parameters between the elderly with sarcopenia and the normal elderly, which were related to absolute muscle strength, suggesting that sarcopenia was a disease mainly caused by decreased muscle mass. In addition, when abnormities were identified in step length, stride length, length of gait line, or length of single support line, it is proposed to take a DXA scan to confirm whether the elderly suffer from sarcopenia.

5.
BMC Sports Sci Med Rehabil ; 14(1): 50, 2022 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-35346343

RESUMEN

BACKGROUND: Fencing is a highly asymmetrical combat sport, that imposes high mechanical demands over repeated exposures on the musculoskeletal structures, a primary cause of injuries in fencers. However, there are limited epidemiological studies on the structural injuries of the foot and ankle in fencers. This study aimed to investigate foot and ankle structural injuries, and explore how metatarsophalangeal joint structural changes may affect the mechanisms of foot and ankle injuries in asymptomatic fencers. METHODS: 3D images of foot and ankle morphology using computed tomography were obtained from ten elite fencers. We then constructed finite element models of the first metatarsophalangeal joint in the foot of their trail legs. The validated models were used to simulate stress distribution changes from different ankle joint angles during lunging. RESULTS: The findings showed that stress distribution changes at the medial and lateral sesamoid may have caused sesamoid fractures, and that habitual and concentrated stress on the metatarsal bones might have flattened the sesamoid groove. This process may damage the integrity of the first metatarsophalangeal joint, and consequently affect the efficiency of the windlass mechanism in fencers. During lunging, different ankle joint angles of the trail foot increased the total stress difference of the medial and lateral foot, and thus influenced the lunging quality and its stability. CONCLUSIONS: Our findings revealed that the asymmetric nature of fencing might have caused asymptomatic foot and ankle structural injuries, and finite element analysis results indicated that this might increase the incidence of the serious injuries if unattended. Regular computed tomography examination should be introduced to monitor elite fencers' lower limb alterations, permitting unique angle adjustments in the trail foot without sacrificing technical or physiologic properties based on the exam results and reduce the lower limb injury risk.

6.
Curr Med Imaging ; 18(8): 830-836, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34879812

RESUMEN

BACKGROUND: Postoperative brain edema is a common complication in patients with high-grade glioma after craniotomy. Both Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are applied to diagnose brain edema. Usually, MRI is considered to be better than CT for identifying brain edema. However, MRI is not generally applied in diagnosing acute cerebral edema in the early postoperative stage. Whether CT is reliable in detecting postoperative brain edema in the early stage is unknown. OBJECTIVE: This study aimed at investigating the agreement and correlation between CT and MRI for measuring early postoperative brain edema. METHODS: Patients with high-grade glioma who underwent craniotomy in the Beijing Tiantan hospital from January 2017 to October 2018 were retrospectively analyzed. The region of interest and operative cavity were manually outlined, and the volume of postoperative brain edema was measured on CT and MRI. Pearson correlation testing and the Intraclass Correlation Coefficient (ICC) were used to evaluate the association and agreement between CT and MRI for detecting the volume of postoperative brain edema. RESULTS: Twenty patients were included in this study. The interrater agreement was perfect for detecting brain edema (CT: κ=1, ICC=0.977, P<0.001; MRI: κ=0.866, ICC=0.963, P<0.001). A significant positive correlation and excellent consistency between CT and MRI were found for measuring the volume of brain edema (rater 1: r=0.97, ICC=0.934, P<0.001; rater 2: r=0.97, ICC=0.957, P<0.001). CONCLUSION: Substantial comparability between CT and MRI is demonstrated for detecting postoperative brain edema. It is reliable to use CT for measuring brain edema volume in the early stage after surgery.


Asunto(s)
Edema Encefálico , Glioma , Edema Encefálico/diagnóstico por imagen , Humanos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos
7.
Front Endocrinol (Lausanne) ; 12: 734362, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34721293

RESUMEN

The aim of the present paper is to determine the sex of the individual using three-dimensional geometric and inertial analyses of metatarsal bones. Metatarsals of 60 adult Chinese subjects of both sexes were scanned using Aquilion One 320 Slice CT Scanner. The three-dimensional models of the metatarsals were reconstructed, and thereafter, a novel software using the center of mass set as the origin and the three principal axes of inertia was employed for model alignment. Eight geometric and inertial variables were assessed: the bone length, bone width, bone height, surface-area-to-volume ratio, bone density, and principal moments of inertia around the x, y, and z axes. Furthermore, the discriminant functions were established using stepwise discriminant function analysis. A cross-validation procedure was performed to evaluate the discriminant accuracy of functions. The results indicated that inertial variables exhibit significant sexual dimorphism, especially principal moments of inertia around the z axis. The highest dimorphic values were found in the surface-area-to-volume ratio, principal moments of inertia around the z axis, and bone height. The accuracy rate of the discriminant functions for sex determination ranged from 88.3% to 98.3% (88.3%-98.3% cross-validated). The highest accuracy of function was established based on the third metatarsal bone. This study showed for the first time that the principal moment of inertia of the human bone may be successfully implemented for sex estimation. In conclusion, the sex of the individual can be accurately estimated using a combination of geometric and inertial variables of the metatarsal bones. The accuracy should be further confirmed in a larger sample size and be tested or independently developed for distinct population/age groups before the functions are widely applied in unidentified skeletons in forensic and bioarcheological contexts.


Asunto(s)
Antropología Forense/métodos , Huesos Metatarsianos/patología , Determinación del Sexo por el Esqueleto/métodos , Adolescente , Adulto , Anatomía Transversal/métodos , Autopsia , Análisis Discriminante , Femenino , Humanos , Imagenología Tridimensional , Masculino , Modelos Anatómicos , Caracteres Sexuales , Interfaz Usuario-Computador , Adulto Joven
8.
Artículo en Inglés | MEDLINE | ID: mdl-32714903

RESUMEN

Hallux valgus (HV), the bunion of the first metatarsophalangeal joint (MTPJ), bothers many adults. No consensus has been reached about the causes of HV, be it a hereditary, or acquired, or multifactorial disease. Nor has agreement been reached using MTPJ angle to assess HV based on X-ray because in most cases the assessment of MTPJ is not reliable as it depends on the posture during scanning. In this study, we assume that HV is predominately acquired and that shoe wearing per se is an important player in HV pathogenesis. To verify our hypothesis, a CT-based finite element (FE) model of the first MTPJ of fossil remains of bear-footed Homo naledi was created and compared to that of five contemporary shoe-wearing wrestlers (10 models from two scans at an interval of about 18 months) because Homo naledi's first MTPJ is an ideal model for non-shoe wearing with parallel sesamoid grooves. We developed the first MTPJ structure transformation method and created MTPJ joint capsule model for both Homo naledi and wrestlers. Constraint on the medial side of the first MTPJ capsule was set to simulate shoe-wearing conditions compared to the lack of medial constraint for barefooted conditions. Analysis of eight FE models of different angles for the first MTPJ of Homo naledi was performed by the first MTPJ transformation method and results showed that stress concentrated on the medial capsule of the first MTPJ in simulated shoe-wearing conditions, even at MTPJ angle of 0°. Increase in the first MTPJ angle further increased stress concentration on the medial side, and stress-growth relationship might reveal the causes of HV. We further developed a method to position the first MTPJ in wrestlers and created CT-based models at two time points. It was evident that the first MTPJ angle increased in all but one athlete, with a maximal increase of 4.03 degrees. This verifies our hypothesis that HV might be developed by wearing shoes. Further longitudinal studies with larger sample sizes are needed to additionally validate our results and determine the magnitude of the effects of shoe wearing on development and progression of HV.

9.
Homo ; 70(2): 139-146, 2019 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-31486825

RESUMEN

The collection of 1550 Homo naledi fossil remains includes six tarsal and five metatarsal bones from the right foot, forming a nearly complete humanlike flat foot arch. The missing right medial cuneiform, however, raises our interest to explore the true structure of Homo naledi's foot arch. We hypothesize that Homo naledi does not have flat foot. To verify our hypothesis, the left medial cuneiform of Homo naledi was mirrored using three-dimensional reconstruction and virtual model analysis. Then, we defined quantities of Euler, standardized the body coordinate system of foot bone and developed a new foot arch reconstruction method based on discrete bones. The reconstructed transverse foot arch corroborated our hypothesis, thus providing biomechanical evidence for interpreting the evolution of human locomotion and bringing novel ideas to the research of the biomechanical mechanism of ankle stability.


Asunto(s)
Pie Plano/patología , Huesos del Pie/anatomía & histología , Fósiles , Hominidae/anatomía & histología , Adulto , Animales , Femenino , Huesos del Pie/diagnóstico por imagen , Historia Antigua , Humanos , Tomografía Computarizada por Rayos X , Adulto Joven
10.
Artículo en Inglés | MEDLINE | ID: mdl-31355195

RESUMEN

The aim of the present study was to develop a new method to reconstruct damaged metatarsophalangeal joint (MTPJ) of Homo naledi's fossil and to deepen the understanding of the first metatarsal head (FMH) morphological adaptation in different gait patterns. To this purpose three methods were introduced. The first served to compare the anthropometric linear and volumetric measurements of Homo naledi's MTPJ to that of 10 various athletes. The second was employed to measure curvature diameter in FMH's medial and lateral grooves for sesamoid bones. The third was used to determine the parallelism between medial and lateral FMH grooves. The anthropometric measurements of middle-distance runner to the greatest extent mimicked that of Homo naledi. Thus, it was used to successfully reconstruct the damaged Homo naledi's MTPJ. The highest curvature diameter of medial FMH groove was found in Homo naledi, while in lateral FMH groove it was the highest in volleyball player, suggesting their increased bear loading. The parallelism of medial and lateral FMH grooves was observed only in Homo naledi, while in investigated athletes it was dis-parallel. Athletes' dis-paralleled structures make first MTPJ simple flexion movement a complicated one: not rotating about one axis, but about many, which may result in bringing a negative effect on running. In conclusion, the presented method for the reconstruction of the damaged foot bone paves the way for morphological and structural analysis of modern population and fossil hominins' gait pattern.

11.
Microsc Microanal ; 24(6): 676-683, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30588909

RESUMEN

The detailed kinetics study of erythrocyte deformability is useful for the early diagnosis of blood diseases and for monitoring the blood rheology. Present solutions for a three-dimensional (3D) reconstruction of erythrocytes has a limited potential. This study aimed to use erythrocyte transmission electron images (ETIs) to evaluate the morphological relationship between adjacent ETIs and generate erythrocytes 3D model. First, ultrathin serial sections of skeletal muscle tissue were obtained using an ultramicrotome. Further, the set of ETIs in a capillary were captured by transmission electron microscopy. The images were aligned by translations and rotations using custom software to optimize the morphological relationship between adjacent ETIs. These coordinate transformations exploit the unique principal axis of inertia of each image to define the body coordinate system and hence provide the means to accurately reconnect the adjacent ETIs. The sum of the distances between the corresponding points on the boundary of adjacent ETIs was minimized and, further, was optimized by using physiological relationship between the adjacent ETIs. The analysis allowed to define precise virtual relationship between the adjacent erythrocytes. Finally, extracted erythrocytes' cross-section images allowed to generate 3D model of the erythrocytes.


Asunto(s)
Deformación Eritrocítica/fisiología , Eritrocitos/fisiología , Imagenología Tridimensional/métodos , Microscopía Electrónica de Transmisión/métodos , Microtomía/métodos , Animales , Masculino , Ratas
12.
J Endod ; 44(5): 816-821, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29336880

RESUMEN

INTRODUCTION: The outcome of periapical surgery has been directly improved with the introduction of novel material formulations. The aim of the study was to compare the retrograde obturation quality of the following materials: calcium silicate (Biodentine; Septodont, Saint-Maur-des-Fosses, France), mineral trioxide aggregate (MTA+; Cerkamed Company, Stalowa Wola, Poland), and glass ionomer cement (Fuji IX; GC Corporation, Tokyo, Japan). METHODS: Materials' wettability was calculated concerning the contact angles of the cements measured using a glycerol drop. Cements' porosity was determined using mercury intrusion porosimetry and micro-computed tomographic (µCT) imaging. Extracted upper human incisors were retrofilled, and µCT analysis was applied to calculate the volume of the gap between the retrograde filling material and root canal dentin. Experiments were performed before and after soaking the materials in simulated body fluid (SBF). RESULTS: No statistically significant differences were found among the contact angles of the studied materials after being soaked in SBF. The material with the lowest nanoporosity (Fuji IX: 2.99% and 4.17% before and after SBF, respectively) showed the highest values of microporosity (4.2% and 3.1% before and after SBF, respectively). Biodentine had the lowest value of microporosity (1.2% and 0.8% before and after SBF, respectively) and the lowest value of microgap to the root canal wall ([10 ± 30] × 10-3 mm3). CONCLUSIONS: Biodentine and MTA possess certain advantages over Fuji IX for hermetic obturation of retrograde root canals. Biodentine shows a tendency toward the lowest marginal gap at the cement-to-dentin interface.


Asunto(s)
Compuestos de Calcio/uso terapéutico , Adaptación Marginal Dental , Dentina/cirugía , Cementos de Ionómero Vítreo/uso terapéutico , Materiales de Obturación del Conducto Radicular/uso terapéutico , Obturación del Conducto Radicular/métodos , Silicatos/uso terapéutico , Ápice del Diente/cirugía , Compuestos de Aluminio/uso terapéutico , Combinación de Medicamentos , Humanos , Óxidos/uso terapéutico , Porosidad , Radiografía Dental , Microtomografía por Rayos X
13.
Scanning ; 2017: 1468596, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29410714

RESUMEN

Cross-sectional imaging is considered the gold standard in diagnosing a range of diseases. However, despite its widespread use in clinical practice and research, no widely accepted method is available to reliably match cross-sectional planes in several consecutive scans. This deficiency can impede comparison between cross-sectional images and ultimately lead to misdiagnosis. Here, we propose and demonstrate a method for finding the same imaging plane in images obtained during separate scanning sessions. Our method is based on the reconstruction of a "virtual organ" from which arbitrary cross-sectional images can be extracted, independent of the axis orientation in the original scan or cut; the key is to establish unique body coordinates of the organ from its principal axes of inertia. To verify our method a series of tests were performed, and the same cross-sectional plane was successfully extracted. This new approach offers clinicians access, after just a single scanning session, to the morphology and structure of a lesion through cross-sectional images reconstructed along arbitrary axes. It also aids comparable detection of morphological and structural changes in the same imaging plane from scans of the same patient taken at different times-thus potentially reducing the misdiagnosis rate when cross-sectional images are interpreted.


Asunto(s)
Diagnóstico por Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Pie/diagnóstico por imagen , Humanos , Masculino
14.
J Am Heart Assoc ; 5(9)2016 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-27633389

RESUMEN

BACKGROUND: MKEY, a synthetic cyclic peptide inhibitor of CXCL4-CCL5 heterodimer formation, has been shown to protect against atherosclerosis and aortic aneurysm formation by mediating inflammation, but whether it modulates neuroinflammation and brain injury has not been studied. We therefore studied the role of MKEY in stroke-induced brain injury in mice. METHODS AND RESULTS: MKEY was injected into mice after stroke with 60 minutes of middle cerebral artery occlusion. Infarct volume and neurological deficit scores were measured. Protein levels of CCL5 and its receptor CCR5 were detected by Western blot and fluorescence-activated cell sorting (FACS), respectively. Numbers of microglia-derived macrophages (MiMΦs) and monocyte-derived MΦs (MoMΦs) in the brain, and their subsets, based on the surface markers CD45, CD11b, CCR2, CX3CR1, and Ly6C, were analyzed by FACS. MΦs and neutrophil infiltration in the ischemic brain were stained with CD68 and myeloperoxidase (MPO), respectively, and assessed by immunofluorescent confocal microscopy. The results showed that expressions of CCL5 and its receptor CCR5, were increased in the ischemic brain after stroke. MKEY injection significantly reduced infarct sizes and improved neurological deficit scores measured 72 hours after stroke. In addition, MKEY injection inhibited the number of MoMΦs, but not MiMΦs, in the ischemic brain. Furthermore, MKEY inhibited protein expression levels of Ly6C,CCR2, and CX3CR1 on MoMΦs. Lastly, the confocal study also suggests that the number of CD68-positive MΦs and MPO-positive neutrophils was inhibited by MKEY injection. CONCLUSIONS: MKEY injection protects against stroke-induced brain injury, probably by inhibiting MoMΦ-mediated neuroinflammation.


Asunto(s)
Encéfalo/efectos de los fármacos , Quimiocina CCL5/efectos de los fármacos , Infarto de la Arteria Cerebral Media/metabolismo , Macrófagos/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Péptidos Cíclicos/farmacología , Factor Plaquetario 4/efectos de los fármacos , Animales , Western Blotting , Encéfalo/citología , Quimiocina CCL5/metabolismo , Dimerización , Citometría de Flujo , Infarto de la Arteria Cerebral Media/fisiopatología , Macrófagos/citología , Masculino , Ratones , Microscopía Confocal , Microscopía Fluorescente , Neutrófilos/citología , Factor Plaquetario 4/metabolismo , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular/fisiopatología
15.
Gait Posture ; 47: 31-6, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27264399

RESUMEN

Walking speed is a basic factor to consider when walking exercises are prescribed as part of a training programme. Although associations between walking speed, step length and falling risk have been identified, the relationship between spontaneous walking pattern and falling risk remains unclear. The present study, therefore, examined the stability of spontaneous walking at normal, fast and slow speed among elderly (67.5±3.23) and young (21.4±1.31) individuals. In all, 55 participants undertook a test that involved walking on a plantar pressure platform. Foot-ground contact data were used to calculate walking speed, step length, pressure impulse along the plantar-impulse principal axis and pressure record of time series along the plantar-impulse principal axis. A forward dynamics method was used to calculate acceleration, velocity and displacement of the centre of mass in the vertical direction. The results showed that when the elderly walked at different speeds, their average step length was smaller than that observed among the young (p=0.000), whereas their anterior/posterior variability and lateral variability had no significant difference. When walking was performed at normal or slow speed, no significant between-group difference in cadence was found. When walking at a fast speed, the elderly increased their stride length moderately and their cadence greatly (p=0.012). In summary, the present study found no correlation between fast walking speed and instability among the elderly, which indicates that healthy elderly individuals might safely perform fast-speed walking exercises.


Asunto(s)
Marcha/fisiología , Equilibrio Postural/fisiología , Velocidad al Caminar/fisiología , Anciano , Femenino , Humanos , Masculino , Adulto Joven
16.
PLoS One ; 8(12): e83839, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24386288

RESUMEN

No consensus has been reached on how musculoskeletal system injuries or aging can be explained by a walking plantar impulse. We standardize the plantar impulse by defining a principal axis of plantar impulse. Based upon this standardized plantar impulse, two indexes are presented: plantar pressure record time series and plantar-impulse distribution along the principal axis of plantar impulse. These indexes are applied to analyze the plantar impulse collected by plantar pressure plates from three sources: Achilles tendon ruptures; elderly people (ages 62-71); and young people (ages 19-23). Our findings reveal that plantar impulse distribution curves for Achilles tendon ruptures change irregularly with subjects' walking speed changes. When comparing distribution curves of the young, we see a significant difference in the elderly subjects' phalanges plantar pressure record time series. This verifies our hypothesis that a plantar impulse can function as a means to assess and evaluate musculoskeletal system injuries and aging.


Asunto(s)
Tendón Calcáneo/lesiones , Tendón Calcáneo/fisiología , Envejecimiento/fisiología , Pie/fisiología , Caminata/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rotura , Propiedades de Superficie , Adulto Joven
17.
PLoS One ; 7(3): e32926, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22412952

RESUMEN

Bone shape is an important factor to determine the bone's structural function. For the asymmetrically shaped and anisotropically distributed bone in vivo, a surface mapping method is proposed on the bases of its geometric transformation invariance and its uniqueness of the principal axes of inertia. Using spiral CT scanning, we can make precise measurements to bone in vivo. The coordinate transformations lead to the principal axes of inertia, with which the prime meridian and the contour can be set. Methods such as tomographic reconstruction and boundary development are employed so that the surface of bone in vivo can be mapped. Experimental results show that the surface mapping method can reflect the shape features and help study the surface changes of bone in vivo. This method can be applied to research into the surface characteristics and changes of organ, tissue or cell whenever its digitalized surface is obtained.


Asunto(s)
Huesos/anatomía & histología , Tomografía Computarizada Cuatridimensional/métodos , Densidad Ósea , Huesos/diagnóstico por imagen , Humanos , Tamaño de los Órganos , Estrés Mecánico
18.
PLoS One ; 6(12): e28868, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22194933

RESUMEN

Bone modeling and remodeling is an optimization process where no agreement has been reached regarding a unified theory or model. We measured 384 pieces of bone in vivo by 64-slice CT and discovered that the bone's center of mass approximately superposes its centroid of shape. This phenomenon indicates that the optimization process of non-homogeneous materials such as bone follows the same law of superposition of center of mass and centroid of shape as that of homogeneous materials. Based upon this principle, an index revealing the relationship between the center of mass and centroid of shape of the compact bone is proposed. Another index revealing the relationship between tissue density and distribution radius is followed. Applying these indexes to evaluate the strength of bone, we have some new findings.


Asunto(s)
Huesos/anatomía & histología , Modelos Anatómicos , Pie/anatomía & histología , Humanos , Imagenología Tridimensional , Masculino , Tamaño de los Órganos , Propiedades de Superficie , Adulto Joven
19.
PLoS One ; 6(3): e17749, 2011 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-21445254

RESUMEN

There has been a controversy as to whether or not the non-pathological flat foot and high-arched foot have an effect on human walking activities. The 3D foot scanning system was employed to obtain static footprints from subjects adopting a half-weight-bearing stance. Based upon their footprints, the subjects were divided into two groups: the flat-footed and the high-arched. The plantar pressure measurement system was used to measure and record the subjects' successive natural gaits. Two indices were proposed: distribution of vertical ground reaction force (VGRF) of plantar and the rate of change of footprint areas. Using these two indices to compare the natural gaits of the two subject groups, we found that (1) in stance phase, there is a significant difference (p<0.01) in the distributions of VGRF of plantar; (2) in a stride cycle, there is also a significant difference (p<0.01) in the rate of change of footprint area. Our analysis suggests that when walking, the VGRF of the plantar brings greater muscle tension to the flat-footed while a smaller rate of change of footprint area brings greater stability to the high-arched.


Asunto(s)
Pie Plano/fisiopatología , Pie/fisiología , Marcha , Humanos
20.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 21(5): 775-8, 2004 Oct.
Artículo en Chino | MEDLINE | ID: mdl-15553856

RESUMEN

In sport games, since the human body movement data are mainly drawn from the sports field with the hues or even interruptions of commercial environment, some difficulties must be surmounted in order to analyze the images. It is obviously not enough just to use the method of grey-image treatment. We have applied the characteristics of the prime number function to the human body movement images and thus introduce a new method of image processing in this article. When trying to deal with certain moving images, we can get a better result.


Asunto(s)
Gráficos por Computador , Fotograbar/métodos , Procesamiento de Señales Asistido por Computador , Deportes , Humanos , Matemática , Modelos Teóricos , Fantasmas de Imagen , Fotograbar/instrumentación
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