Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Front Sports Act Living ; 5: 1109581, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37090815

RESUMEN

In the present study, dynamic stability during level walking and obstacle crossing in typically developing children aged 2-5 years (n = 13) and healthy young adults (n = 19) was investigated. The participants were asked to walk along unobstructed and obstructed walkways. The height of the obstacle was set at 10% of the leg length. Gait motion was captured by three RGB cameras. 2D body landmarks were estimated using OpenPose, a marker-less motion capture algorithm, and converted to 3D using direct linear transformation (DLT). Dynamic stability was evaluated using the margin of stability (MoS) in the forward and lateral directions. All the participants successfully crossed the obstacles. Younger children crossed the obstacle more carefully to avoid falls, as evidenced by obviously decreased gait speed just before the obstacle in 2-year-olds and the increased in maximum toe height with younger age. There was no significant difference in the MoS at the instant of heel contact between children and adults during level walking and obstacle crossing in the forward direction, although children increased the step length of the lead leg to a greater extent than the adults to ensure base of support (BoS)-center of mass (CoM) distance. In the lateral direction, children exhibited a greater MoS than adults during level walking [children: 9.5%, adults: 6.5%, median, W = 39.000, p < .001, rank-biserial correlation = -0.684]; however, some children exhibited a smaller MoS during obstacle crossing [lead leg: -5.9% to 3.6% (min-max) for 4 children, 4.7%-6.4% [95% confidence interval (CI)] for adults, p < 0.05; trail leg: 0.1%-4.4% (min-max) for 4 children, 4.7%-6.4% (95% CI) for adults, p < 0.05]]. These results indicate that in early childhood, locomotor adjustment needed to avoid contact with obstacles can be observed, whereas lateral dynamic stability is frangible.

2.
Sensors (Basel) ; 23(8)2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-37112477

RESUMEN

Depth information is important for postural stability and is generated by two visual systems: binocular and motion parallax. The effect of each type of parallax on postural stability remains unclear. We investigated the effects of binocular and motion parallax loss on static postural stability using a virtual reality (VR) system with a head-mounted display (HMD). A total of 24 healthy young adults were asked to stand still on a foam surface fixed on a force plate. They wore an HMD and faced a visual background in the VR system under four visual test conditions: normal vision (Control), absence of motion parallax (Non-MP)/binocular parallax (Non-BP), and absence of both motion and binocular parallax (Non-P). The sway area and velocity in the anteroposterior and mediolateral directions of the center-of-pressure displacements were measured. All postural stability measurements were significantly higher under the Non-MP and Non-P conditions than those under the Control and Non-BP conditions, with no significant differences in the postural stability measurements between the Control and Non-BP conditions. In conclusion, motion parallax has a more prominent effect on static postural stability than binocular parallax, which clarifies the underlying mechanisms of postural instability and informs the development of rehabilitation methods for people with visual impairments.


Asunto(s)
Gafas Inteligentes , Realidad Virtual , Adulto Joven , Humanos , Movimiento (Física) , Equilibrio Postural , Visión Binocular
3.
PLoS One ; 18(2): e0281037, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36758023

RESUMEN

BACKGROUND: Understanding typical gait development is critical in developing suitable physical therapy methods for gait disorders. This study investigated the developmental changes and controlling mechanisms of straight gait. METHODS: We conducted an experimental procedure among 90 participants, including 76 typically developing children and 14 healthy adults. The children were divided according to age into 3-4, 5-6, 7-8, and 9-10-year age groups. We created two indices to quantify straight gait using the extrapolated center of mass (XCOM; goal index, XCOMG and actual progress index, XCOMP), which were calculated and compared between the groups. Stepwise multiple regression was used to examine the effects of each gait variable on XCOMG and XCOMP. To eliminate the effects of multicollinearity, correlation coefficients were calculated for all gait variables. RESULTS: Both XCOMG and XCOMP decreased gradually with age and were significantly larger in the 3-4 and 5-6 year groups than in the adult group. Multiple regression analysis showed that step velocity, step width, and the coefficiente of variation (CV) of the step width had independent coefficients of variation for the XCOMG, and the symmetry index of step time, step width, and the CV of the step width had independent CV for the XCOMP. These variables were selected as significant variables. The results showed that meandering gait was more pronounced at younger ages. Furthermore, straight gait observed in adulthood was achieved by the age of 7. CONCLUSION: Pace (step velocity) and stability (step width and CV of step width) may contribute to XCOMG, which assesses the ability to proceed in the direction of the target. Stability and symmetry may contribute to XCOMP, which assesses the ability to walk straight in one's own direction of progress. Physical therapists could apply these indices in children to assess their ability to walk straight.


Asunto(s)
Marcha , Caminata , Adulto , Niño , Humanos , Correlación de Datos , Motivación
4.
J Mot Behav ; 55(6): 594-602, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-34148509

RESUMEN

The purpose of this study was to determine how the application of static stretching to ankle plantar flexors affects postural control during maximum forward leaning. Twenty-six volunteer males (age 21.4 ± 1.2 years) were randomly assigned to stretching and control conditions. Participants conducted 5-min stretching on a stretch board for the stretching condition and were kept standing for 6-min for the control condition. Before and after intervention, the range of motion (ROM) at ankle dorsiflexion and the center of pressure (COP) excursion during maximal forward leaning were determined. Mean anteroposterior COP position, COP velocity and COP areas were calculated to compare the change in postural control. After stretching, ROM was significantly increased. During maximal forward leaning after stretching, both COP position and velocity showed significant increases compared to before stretching. Moreover, COP position and velocity in the stretching condition were significantly higher than in the control condition after stretching. No significant differences were found in COP area before and after stretching. Five-minute stretching increased not only ROM but also the anterior limit of stability while maintaining posture and led to faster COP shift than before stretching. These results indicate that static stretching would improve dynamic postural control as well.


Asunto(s)
Ejercicios de Estiramiento Muscular , Humanos , Masculino , Adulto Joven , Tobillo , Articulación del Tobillo , Equilibrio Postural , Postura
5.
Gait Posture ; 97: 1-7, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35843008

RESUMEN

BACKGROUND: The dorsal parietal visual system plays an important role in self-motion perception and spatial cognition. It also strongly responds to visual inputs from the lower visual field. Postural control is modified in a process called sensory reweighting based on the reliability of available sensory sources. The question of whether visual stimuli presented to either the lower or upper visual field affect postural control and sensory reweighting has not been resolved. RESEARCH QUESTION: Do visual stimuli presented to the lower and upper visual fields affect postural control and sensory reweighting? METHODS: Twenty-nine healthy young adults participated in the study. Four conditions (full visual field, upper visual field, lower visual field, and no optic flow condition) were simulated in a VR environment using a head-mounted display. The optic flow stimuli used were swarms of small white spheres originating from the central point of the visual field, moving radially towards the periphery, and expanding across the scene. Participants were instructed to stand quietly for 50 s under each visual condition. Using force plate signals, we measured the center of pressure (COP) signal in the horizontal plane and calculated its 95 % ellipse area, root mean square (RMS) deviations, the mean velocity, and power spectral density (PSD). RESULTS: Optic flow in the full and lower visual fields produced significantly smaller 95 % ellipse area and RMS of COP in the anterior-posterior direction compared to optic flow in the upper visual field. Furthermore, the PSD of the lower frequency band (0-0.3 Hz) was decreased and that of higher frequency bands (0.3-1 Hz and 1-3 Hz) was increased for the lower compared to the upper visual field. SIGNIFICANCE: Visual feedback affects static postural control more when presented in the lower visual field compared to the upper visual field.


Asunto(s)
Retroalimentación Sensorial , Flujo Optico , Humanos , Equilibrio Postural , Reproducibilidad de los Resultados , Campos Visuales , Adulto Joven
7.
Front Hum Neurosci ; 15: 740509, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34776908

RESUMEN

Knowledge about the developmental process of dynamic balance control comprised of upper arms and upper legs coordination and trunk and pelvis twist coordination is important to advance effective balance assessment for abnormal development. However, the mechanisms of these coordination and stability control during gait in childhood are unknown.This study examined the development of dynamic postural stability, upper arm and upper leg coordination, and trunk and pelvic twist coordination during gait, and investigated the potential mechanisms integrating the central nervous system with inter-limb coordination and trunk and pelvic twist coordination to control extrapolated center of the body mass (XCOM). This study included 77 healthy children aged 3-10 years and 15 young adults. The child cohort was divided into four groups by age: 3-4, 5-6, 7-8, and 9-10 years. Participants walked barefoot at a self-selected walking speed along an 8 m walkway. A three-dimensional motion capture system was used for calculating the XCOM, the spatial margin of stability (MoS), and phase coupling movements of the upper arms, upper legs, trunk, and pelvic segments. MoS in the mediolateral axis was significantly higher in the young adults than in all children groups. Contralateral coordination (ipsilateral upper arm and contralateral upper leg combination) gradually changed to an in-phase pattern with increasing age until age 9 years. Significant correlations of XCOMML with contralateral coordination and with trunk and pelvic twist coordination (trunk/pelvis coordination) were found. Significant correlations between contralateral coordination and trunk/pelvis coordination were observed only in the 5-6 years and at 7-8 years groups.Dynamic postural stability during gait was not fully mature at age 10. XCOM control is associated with the development of contralateral coordination and trunk and pelvic twist coordination. The closer to in-phase pattern of contralateral upper limb coordination improved the XCOM fluctuations. Conversely, the out-of-phase pattern (about 90 degrees) of the trunk/pelvis coordination increased theXCOM fluctuation. Additionally, a different control strategy was used among children 3-8 years of age and individuals over 9 years of age, which suggests that 3-4-year-old children showed a disorderly coordination strategy between limb swing and torso movement, and in children 5-8 years of age, limb swing depended on trunk/pelvis coordination.

8.
Front Hum Neurosci ; 15: 674960, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34335209

RESUMEN

BACKGROUND: Effective training of the backward step response could be beneficial to improve postural stability and prevent falls. Unpredicted perturbation-based balance training (PBT), widely known as compensatory-step training, may enhance the fear of falling and the patterns of postural muscle co-contraction. Contrastingly, PBT with predictable direction or both direction and timing would suppress the fear and the co-contraction patterns during training, but the efficacy of predictable PBT for unpredictable perturbations is still unknown. OBJECTIVE: To compare the adaptation effects of compensatory-step training with and without predictable perturbations on backward stepping against unpredictable perturbations. METHODS: Thirty-three healthy young adults were randomly assigned to one of the following step training groups: Unpredicted, Predicted, and Self-initiated. In training sessions, participants were perturbed to induce a compensatory step with (Predicted group) or without (Unpredicted group) knowledge of the perturbation's direction or while knowing both the direction and timing of the perturbation (Self-initiated group). In test sessions (pre- and post-training), participants were instructed to recover their postural stability in response to an unpredicted perturbation. The margin of stability (MOS), center of mass (COM) shift, and step characteristics were measured during a backward step in both test and training sessions. RESULTS: All three groups showed a significant increase in the step length and velocity in the post-training sessions compared to those in the pre-training sessions. Moreover, in the Unpredicted and Predicted groups, but not in the Self-initiated group, the MOS at step contact was significantly increased following the training session. In addition, the Self-initiated group showed a significant increase in COM shift at 50 ms after slip onset during training compared to the Unpredicted and Predicted groups. CONCLUSION: Unpredicted and predicted PBT improve step characteristics during backward stepping against unpredictable perturbations. Moreover, the unpredictable PBT and PBT with direction-predictable perturbations enhance the feedback postural control reflected as the postural stability at step contact.

9.
Biomed Res ; 42(3): 103-108, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34092751

RESUMEN

Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system (CNS). This study examined the effect of specific inhibition of α5 subunit-containing GABAA receptors (α5GABAAR) on the behavioral profile and neuronal activity of the CNS using a compound called L-655,708, which is a selective negative allosteric modulator of α5GABAAR. L-655,708 administration significantly increased locomotor activity without anxiety-related behavior. Furthermore, L-655,708 administration significantly increased c-Fos mRNA expression (a neuronal activity marker) in motor area of the cerebral cortex, whereas it hardly altered c-Fos mRNA expression in the sensory cortex, hippocampus, and spinal cord. This study revealed for the first time that alteration of neuronal activity with specific inhibition of α5GABAAR differs depending on each CNS region. α5GABAAR could be a potential target for modulating CNS excitability and behavioral activity.


Asunto(s)
Ansiedad/inducido químicamente , Corteza Cerebral/efectos de los fármacos , Corteza Motora/patología , Neuronas/metabolismo , Receptores de GABA-A/química , Animales , Conducta , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Imidazoles/química , Locomoción/efectos de los fármacos , Masculino , Corteza Motora/efectos de los fármacos , Movimiento , Proteínas Proto-Oncogénicas c-fos/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Médula Espinal/efectos de los fármacos
10.
Gait Posture ; 86: 233-239, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33774584

RESUMEN

BACKGROUND: Integration of visual, vestibular, and proprioceptive sensations contributes to postural control. People with peripheral visual field loss have serious postural instability. However, the directional specificity of postural stability and sensory reweighting caused by gradual peripheral visual field loss remain unclear. RESEARCH QUESTION: What are the effects of peripheral visual field loss on static postural control? METHODS: Fifteen healthy young adults participated in this study. The participants were asked to stand quietly on a foam surface. Three conditions of virtual visual field loss (90°, 45°, and 15°) were provided by a head-mounted display, and ground reaction forces were collected using a force plate to calculate the displacements of the center of pressure (COP). RESULTS: The root mean square (RMS), mean velocity, and 95% ellipse area of COP displacements in the horizontal plane increased, and RMS in the anteroposterior (AP) direction was unchanged under the smallest visual field condition compared to the largest one. The power spectrum density of COP displacements in the low-frequency band was decreased and that in the medium-frequency band was increased in the AP direction. SIGNIFICANCE: During quiet standing of young healthy adults with peripheral visual field loss, increased peripheral visual field loss resulted in lower postural stability. Postural stability in the AP direction was maintained contrary to the functional sensitivity hypothesis. Peripheral visual field loss reduced the weighting of the visual input and increased that of the vestibular input in the AP direction to maintain equilibrium.


Asunto(s)
Equilibrio Postural/fisiología , Trastornos de la Visión/fisiopatología , Campos Visuales/fisiología , Femenino , Humanos , Masculino , Propiocepción , Vestíbulo del Laberinto , Adulto Joven
11.
Neurosci Lett ; 749: 135749, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33610667

RESUMEN

Exercise is recognized to increase the expression of neurotrophic genes in the hippocampus and prevent cognitive impairment. Histone deacetylase (HDAC) inhibitor acetylate histones and enhance gene transcription in epigenetic regulation. HDAC inhibitors are expected to be an efficacious pharmacological treatment for cognitive function. This study aimed to examine the effect of HDAC inhibitors and exercise on epigenetic markers and neurotrophic gene expression in the hippocampus to find a more enriched brain conditioning for cognitive function based on the synergic effects of pharmacological treatment and behavioral therapy. Thirteen-week-old male mice were divided into four groups. Intraperitoneal administration of an HDAC inhibitor (1.2 g/kg sodium butyrate, NaB) and treadmill exercise (approximately 10 m/min for 60 min) were performed 5 days a week for 4 weeks. NaB administration increased the expression of an immediate-early gene, a neurotrophin, and a neurotrophin receptor in the hippocampus. These results indicate that HDAC inhibition could present an enriched platform for neuronal plasticity in the hippocampus and cognitive function. The novel object recognition test showed that NaB administration increased the score. Notably, the step-through passive avoidance test showed improved learning and memory in the presence of exercise and exercise, indicating that the mice acquired fear memory, specifically in the presence of NaB administration plus exercise. This study found that repetitive administration of HDAC inhibitors improved cognitive function and HDAC inhibitor administration plus exercise has a synergic effect on learning and memory, accompanying the enhancement of crucial gene transcriptions for neuronal plasticity in the hippocampus.


Asunto(s)
Expresión Génica/efectos de los fármacos , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Histona Desacetilasas/efectos de los fármacos , Memoria/efectos de los fármacos , Plasticidad Neuronal/efectos de los fármacos , Animales , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ácido Butírico/farmacología , Cognición/efectos de los fármacos , Cognición/fisiología , Epigénesis Genética/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Masculino , Ratones , Condicionamiento Físico Animal/fisiología
12.
Brain Res ; 1751: 147191, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33152341

RESUMEN

The objective of this study was to examine the effect of epigenetic treatment using an histone deacetylases (HDAC) inhibitor in addition to aerobic exercise on the epigenetic markers and neurotrophic gene expressions in the motor cortex, to find a more enriched brain pre-conditioning for motor learning in neurorehabilitation. ICR mice were divided into four groups based on two factors: HDAC inhibition and exercise. Intraperitoneal administration of an HDAC inhibitor (1.2 g/kg sodium butyrate, NaB) and treadmill exercise (approximately at 10 m/min for 60 min) were conducted five days a week for four weeks. NaB administration inhibited total HDAC activity and enhanced acetylation level of histones specifically in histone H4, accompanying the increase of transcription levels of immediate-early genes (IEGs) (c-fos and Arc) and neurotrophins (BDNF and NT-4) crucial for neuroplasticity in the motor cortex. However, exercise enhanced HDAC activity and acetylation level of histone H4 and H3 without the modification of transcription levels. In addition, there were no synergic effects between HDAC inhibition and the exercise regime on the gene expressions. This study showed that HDAC inhibition could present more enriched condition for neuroplasticity to the motor cortex. However, exercise-induced neurotrophic gene expressions could depend on exercise regimen based on the intensity, the term etc. Therefore, this study has a novelty suggesting that pharmacological HDAC inhibition could be an alternative potent approach to present a neuronal platform with enriched neuroplasticity for motor learning and motor recovery, however, an appropriate exercise regimen is expected in this approach.


Asunto(s)
Ácido Butírico/farmacología , Plasticidad Neuronal/genética , Condicionamiento Físico Animal/fisiología , Acetilación/efectos de los fármacos , Animales , Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ácido Butírico/metabolismo , Cognición/fisiología , Epigénesis Genética/efectos de los fármacos , Epigénesis Genética/fisiología , Femenino , Expresión Génica/genética , Expresión Génica/fisiología , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/fisiología , Hipocampo/metabolismo , Inhibidores de Histona Desacetilasas/metabolismo , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Masculino , Ratones , Ratones Endogámicos ICR , Corteza Motora/metabolismo , Corteza Motora/fisiología , Plasticidad Neuronal/fisiología , Neuronas/metabolismo
13.
Hum Mov Sci ; 75: 102736, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33310381

RESUMEN

This study aimed to analyze the development of direction specificities of temporal and spatial control and the coordination pattern of anticipatory postural adjustment (APA) along the anteroposterior (AP) and mediolateral (ML) directions during gait initiation (GI) in children aged 3-10 years. This study included 72 healthy children aged 3-10 years and 14 young adults. The child population was divided into four groups by age: 3-4, 5-6, 7-8, and 9-10 years. The GI task included GI using the dominant limb. The peak center of feet pressure (COP) shifts during APAs (APApeak), initiation time of COP shifts (APAonset), and the COP vectors in the horizontal plane were calculated to evaluate the direction specificity of spatial, temporal, and coordination control, respectively. A difference in direction specificity development was found for the APApeak. The APApeak in the mediolateral axis, but not in the anteroposterior axis, was significantly higher in the 7-8 years age group than in other groups. Although APAonset was not found for direction specificity, a significant difference between the adult and children groups (5-6 years, 7-8 years, and 9-10 years) was observed in the direction of the COP vector. In conclusion, the developmental process of the spatial, temporal, and coordination control of APAs during GI varied with age. Furthermore, the spatial control and coordination pattern of APAs was found to be direction specific. All components of APAs, namely temporal and spatial control, coordination pattern, and direction specificities, should be analyzed to capture the developmental process of anticipatory postural control.


Asunto(s)
Marcha/fisiología , Equilibrio Postural , Postura , Niño , Preescolar , Cognición , Femenino , Humanos , Masculino , Análisis Espacio-Temporal , Adulto Joven
14.
Cardiovasc Interv Ther ; 36(3): 330-337, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32683547

RESUMEN

The objective of this study is to develop a model for predicting the time of early symptomatic (delayed or nonhealing wound) restenosis after infrapopliteal angioplasty in patients with critical limb ischemia (CLI). This is a single-center retrospective cohort study evaluating 60 de novo infrapopliteal lesions of 38 limbs in 35 patients with CLI, who underwent successful endovascular treatment (EVT) from October 2016 to December 2018 and follow-up angiography within 3 months from the procedure. Outcome measures were binary restenosis at follow-up angiography and clinical outcome at 3 months. Patient/limb/lesion characteristics were compared between the restenosis and non-restenosis groups. Angiographic restenosis predictors were assessed to develop a model for predicting the time of restenosis using multinomial logistic regression. The restenosis rate at follow-up angiography (median time, 41 days [IQR 27-58 days]) was 38% (23/60). After adjustment for covariables, longer period between EVT and follow-up angiography and lower C-reactive protein (CRP) were the predictors of angiographic restenosis. We developed a model for predicting the time of early symptomatic restenosis with a probability of 70%: "Days = 200 - 2.1 age - 13 CTO + 3.3 CRP" (R2 = 0.81, RMSE = 0.27), e.g., 80 years old, CTO (+), CRP 4.4 mg/dl: 32.2 days. The predictive model including age, CTO, and CRP might allow estimation of the period for the angiographic restenosis development.


Asunto(s)
Angioplastia de Balón/métodos , Isquemia/cirugía , Pierna/irrigación sanguínea , Arteria Poplítea , Anciano , Anciano de 80 o más Años , Angiografía , Femenino , Humanos , Isquemia/diagnóstico , Masculino , Recurrencia , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
15.
J Med Biol Eng ; 40(3): 340-347, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32421097

RESUMEN

Purpose: The aim of this study was to determine the effective biomechanical technique for suctioning phlegm. Methods: A novel tracheal suctioning simulator combined with a motion capture system was used to calculate the amount of simulated phlegm suctioned and the biomechanical parameters of the associated suctioning manoeuvre. A laboratory study, including 12 nurses with > 3 years of suctioning experience and 12 nursing students without any clinical suctioning experience, was conducted. The amount of phlegm suctioned, the maximum length of catheter insertion, and the biomechanical parameters of hand movement were calculated. Results: The mean amount of phlegm suctioned per second was significantly larger in the experienced group than in the non-experienced group. The amount of phlegm suctioned correlated positively with the length of the vertical path of motion of the wrist and forearm, and with the angular velocity of thumb rotation in both the groups. Conclusion: Greater vertical motion of the wrist and thumb rotation improved the effectiveness of phlegm suctioning and prevented the need for deep suctioning, which is unsafe.

16.
Gait Posture ; 68: 174-180, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30497037

RESUMEN

BACKGROUND: The ability to control the center of mass (COM) during single-leg standing (SLS) is imperative for individuals to walk independently. However, detailed biomechanical features of postural control during SLS performed by children remain to be comprehensively investigated. RESEARCH QUESTION: We aimed to investigate the development of postural control during SLS in children aged 3-10 years. METHODS: Forty-eight healthy children (26 boys and 22 girls) aged 3-10 years and 11 young adults participated in this experiment. The child population was divided into four groups by age: 3-4, 5-6, 7-8, and 9-10 years. The SLS task included standing on a single leg as long and as steady as possible for up to 30 s. A three-dimensional motion capture system and two force plates were used for calculating the COM and center of pressure (COP). The task was divided into three phases (accelerated, decelerated, and steady) on the basis of the relationship between COM and COP. RESULTS: COP-COM distances in the 5-6 years' and 7-8 years' groups were significantly increased during the acceleration phase when compared with those in the adult group. Furthermore, COP-COM distances during the decelerated phase were significantly higher in all children's groups compared with those in the adult group. Lastly, COP-COM distance during the steady phase was significantly higher in the 3-4 year age group than in the 9-10 year age and adults groups. SIGNIFICANCE: These results suggest that postural control during the acceleration and steady phases mature by 9 years. Conversely, children ∼10 years did not attain adult-like levels of postural control during the decelerated phase. The developmental process for postural control at each phase possibly plays a significant role in the basic biomechanics of movement and does not display a monotonic pattern.


Asunto(s)
Movimiento/fisiología , Equilibrio Postural/fisiología , Postura/fisiología , Caminata/fisiología , Aceleración , Fenómenos Biomecánicos , Biofisica , Niño , Preescolar , Desaceleración , Femenino , Humanos , Masculino , Presión , Posición de Pie
17.
J Interv Card Electrophysiol ; 53(1): 53-61, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29951865

RESUMEN

BACKGROUND: Left lateral mitral isthmus (LLMI) linear ablation is a safe and effective technique for treating left mitral flutter. LLMI linear ablation with pulmonary vein isolation may reduce the recurrence of persistent atrial fibrillation. However, epicardial ablation within the coronary sinus (CS) is often required to create the LLMI block line. If the necessity for epicardial ablation is checked before ablation, complications may be reduced. METHODS: We recruited 135 patients who underwent their first LLMI ablation and divided them into two groups, one group not requiring epicardial ablation for creating a conduction block at the LLMI (Endo group) and another requiring it (Epi group). These two groups were compared in terms of the electrogram characteristics of the CS. RESULTS: Bidirectional block through the LLMI was achieved in 94.8% of patients. In 42% of these patients, not only the endocardium but also the epicardium was ablated. As for the electrogram, the Endo group had lower atrium voltage and atrioventricular voltage ratios (p = 0.009) than the Epi group before LLMI ablation. By contrast, there were no significant differences in the atrium voltage and the atrioventricular voltage ratio between these two groups after LLMI ablation. CONCLUSIONS: For creating a conduction block at the LLMI, the atrium voltage and the atrioventricular voltage ratio in the CS before ablation are important. The atrioventricular voltage ratio is a crucial criterion for determining whether epicardial ablation is necessary; furthermore, the atrioventricular voltage ratio in the CS must be reduced with or without epicardial ablation.


Asunto(s)
Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/cirugía , Ablación por Catéter/métodos , Seno Coronario/cirugía , Electrocardiografía/métodos , Bloqueo Cardíaco/fisiopatología , Anciano , Fibrilación Atrial/mortalidad , Aleteo Atrial/diagnóstico por imagen , Aleteo Atrial/mortalidad , Aleteo Atrial/cirugía , Ablación por Catéter/mortalidad , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Bloqueo Cardíaco/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Pericardio/diagnóstico por imagen , Pericardio/cirugía , Venas Pulmonares/cirugía , Recurrencia , Estudios Retrospectivos , Medición de Riesgo , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
18.
Intern Med ; 57(3): 363-366, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29093419

RESUMEN

A 68-year-old man with a history of coronary artery bypass surgery was referred to our hospital because of pre-syncope on effort. During a treadmill exercise electrocardiogram test, the patient developed advanced atrioventricular block associated with dizziness. Coronary angiography revealed significant stenosis of the right coronary artery, which had not existed at the time of the bypass surgery. We implanted drug-eluting stents in the stenotic lesion, and an exercise test showed resolution of the atrioventricular block. Exercise-induced atrioventricular block is rare, and it is necessary to distinguish it from ischemic heart disease, especially in patients with a history of coronary artery disease.


Asunto(s)
Bloqueo Atrioventricular/etiología , Bloqueo Atrioventricular/cirugía , Puente de Arteria Coronaria/efectos adversos , Enfermedad de la Arteria Coronaria/cirugía , Estenosis Coronaria/etiología , Ejercicio Físico/fisiología , Anciano , Bloqueo Atrioventricular/diagnóstico por imagen , Estenosis Coronaria/diagnóstico por imagen , Estenosis Coronaria/cirugía , Humanos , Masculino , Síncope/diagnóstico por imagen , Síncope/fisiopatología , Resultado del Tratamiento
19.
Neurosci Res ; 133: 28-37, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29141188

RESUMEN

Previous findings have revealed abnormal visual attention or processing of faces among individuals with autism spectrum condition (ASC). However, little attention has been paid to the relationship between autistic traits and neural mechanisms associated with representing facial values. Using fMRI, we investigated the patterns of brain activity in the vmPFC and VS in response to faces of elderly males, elderly females, young males, and young females. During fMRI, subjects with a relatively high autism quotient (high group) and those with a relatively low autism quotient (low group) were presented with a face and asked to rate its pleasantness. After fMRI, the subjects were presented with pairs of faces and asked to select the face that they preferred. Our results indicate a dissociable modulatory effect of autistic traits on the vmPFC and VS: The vmPFC activity in the low group was more sensitive to age differences in female faces compared to that in the high group, whereas VS activity did not show differences between groups. These results suggest that, in the BVS, autistic traits selectively modulate the vmPFC activity associated with facial value representation.


Asunto(s)
Trastorno del Espectro Autista/diagnóstico por imagen , Cara , Reconocimiento Visual de Modelos/fisiología , Corteza Prefrontal/diagnóstico por imagen , Factores Sexuales , Adulto , Anciano , Análisis de Varianza , Mapeo Encefálico , Emociones , Femenino , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Estimulación Luminosa , Tiempo de Reacción/fisiología , Adulto Joven
20.
Gait Posture ; 58: 188-193, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28800501

RESUMEN

Augmented sensory biofeedback (BF) for postural control is widely used to improve postural stability. However, the effective sensory information in BF systems of motor learning for postural control is still unknown. The purpose of this study was to investigate the learning effects of visual versus auditory BF training in dynamic postural control. Eighteen healthy young adults were randomly divided into two groups (visual BF and auditory BF). In test sessions, participants were asked to bring the real-time center of pressure (COP) in line with a hidden target by body sway in the sagittal plane. The target moved in seven cycles of sine curves at 0.23Hz in the vertical direction on a monitor. In training sessions, the visual and auditory BF groups were required to change the magnitude of a visual circle and a sound, respectively, according to the distance between the COP and target in order to reach the target. The perceptual magnitudes of visual and auditory BF were equalized according to Stevens' power law. At the retention test, the auditory but not visual BF group demonstrated decreased postural performance errors in both the spatial and temporal parameters under the no-feedback condition. These findings suggest that visual BF increases the dependence on visual information to control postural performance, while auditory BF may enhance the integration of the proprioceptive sensory system, which contributes to motor learning without BF. These results suggest that auditory BF training improves motor learning of dynamic postural control.


Asunto(s)
Biorretroalimentación Psicológica/métodos , Audición/fisiología , Aprendizaje/fisiología , Propiocepción/fisiología , Visión Ocular/fisiología , Femenino , Voluntarios Sanos , Humanos , Masculino , Distribución Aleatoria , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...