RESUMEN
OBJECTIVES: This study aims to conduct a thorough characterization of hand morphology. Employing a 2D geometric morphometric approach, we scrutinize individual fingers and the palm, delineating the ontogenetic trajectories for each biological sex and investigating the alterations that take place at various stages of human development. MATERIALS AND METHODS: A set of thirty-two 2D anatomical landmarks were assessed in a sex-balanced sample of human hands (F = 275, M = 250 males), spanning all stages of human development. Following Procrustes registration, the data on size and shape for individual fingers and the palm were examined for each biological sex and age group. Regression analysis was utilized to quantify ontogenetic trajectories for each biological sex. RESULTS: The findings suggest a gradual escalation in sexual dimorphism throughout human development, with statistically noteworthy distinctions becoming apparent in size starting at the age of 3, and in shape from the age of 7 onwards. Additionally, our analyses uncover a distinctive sigmoid pattern between sexes, indicating that biological male hands exhibit a sturdier build compared to biological female hands from early childhood onward. CONCLUSIONS: In conclusion, this study enriches our insights into sexual dimorphism in human hands, stressing the importance of considering both size and shape across different ontogenetic stages. These findings not only expand our understanding of human biological variation but also lay the foundation for future interdisciplinary research in diverse scientific domains.
Asunto(s)
Mano , Caracteres Sexuales , Humanos , Masculino , Femenino , Mano/anatomía & histología , Mano/crecimiento & desarrollo , Preescolar , Lactante , Niño , Adolescente , Adulto , Adulto Joven , Antropología Física/métodos , Recién Nacido , Antropometría/métodos , Dedos/anatomía & histología , Dedos/crecimiento & desarrolloRESUMEN
BACKGROUND: In 2015, the first bilateral pediatric hand-forearm transplant was performed in an 8-year-old boy. The growth rate of the transplanted upper extremities was unknown at the time. METHODS: Forearm and hand radiographs were obtained annually. Radius and ulna measurements were performed by multiple coauthors and mathematically normalized using a standardized methodology. The Greulich and Pyle atlas was used to estimate hand bone age. RESULTS: From July of 2015 to July of 2019, unadjusted bone length (metaphysis to metaphysis) increased 38.8 and 39.6 mm for the left radius and ulna, and 39.5 and 35.8 mm for the right radius and ulna, respectively. Distal physes of the donor limbs increasingly contributed to overall bone length relative to proximal physes. Normalized growth between the two limbs was statistically similar. At each annual follow-up, the bone age increased by 1 year. CONCLUSIONS: Successful pediatric hand-forearm transplantation offers the advantage of growth similar to that of nontransplanted pediatric patients. The transplanted distal physes contributes more to the overall growth, paralleling normal pediatric growth patterns. Chronologic age parallels the increase in bone age. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.
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Traumatismos del Antebrazo/cirugía , Antebrazo/crecimiento & desarrollo , Traumatismos de la Mano/cirugía , Trasplante de Mano/métodos , Mano/crecimiento & desarrollo , Determinación de la Edad por el Esqueleto/estadística & datos numéricos , Niño , Desarrollo Infantil , Estudios de Seguimiento , Antebrazo/cirugía , Humanos , Masculino , Estudios de Casos Únicos como Asunto , Resultado del TratamientoRESUMEN
Proper bone age assessment is crucial for the clinical diagnosis and evaluation of treatment responses. We investigated the applicability of Greulich and Pyle (GP), and Tanner and Whitehouse 3 (TW3) methods for children in modern Taiwan, using computer-aided diagnosis. Hand and wrist radiographs were obtained from 611 children (3-17 years) who came to our emergency department due to trauma. Ages 0 to 2 years old were excluded because of a limited number of cases. Skeletal maturation was assessed using the BoneXpert (version 2.5.4.1 automated software), which determines GP and TW3 bone age. The two scoring systems were evaluated for comparing the chronological ages in each subgroup. In boys, mean GP bone age vs mean chronological ages were delayed for ages 3 to 11 and advanced for age 12 to 17. In girls, mean GP bone age vs mean chronological ages was delayed for ages 4 to 8 and 17, and advanced for ages 3 and 9 to 17. In boys, the mean TW3 bone ages vs mean chronological ages were delayed for ages 5 to 10 except age 8, and advanced for ages 3 to 4, 8, and 11 to 15. In girls, the mean TW3 bone ages vs mean chronological ages were delayed for ages 4 to 12, and advanced for ages 3 and 13 to 14. By using the BoneXpert automatic software, we established bone age reference standards for children in Taiwan. Clinical application of GP and TW3 scoring methods can be adjusted according to our results to better assess bone age.
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Envejecimiento/fisiología , Antropometría/métodos , Mano/anatomía & histología , Radiografía/estadística & datos numéricos , Muñeca/anatomía & histología , Adolescente , Niño , Preescolar , Femenino , Mano/diagnóstico por imagen , Mano/crecimiento & desarrollo , Humanos , Masculino , Estudios Retrospectivos , Factores Sexuales , Taiwán , Muñeca/diagnóstico por imagen , Muñeca/crecimiento & desarrolloRESUMEN
INTRODUCTION: The aim of this study was to evaluate the height growth of Class I and III orthodontic patients according to the Fishman skeletal maturation index (SMI) and to compare it with that of a general population. METHODS: The study sample included 81 Class I and 71 Class III adolescents who had height measurements and hand-wrist radiographs taken annually and categorized according to SMI. Height completion rate, residual height, height increase per sequential SMI stage, and height velocity were analyzed. Sex differences were evaluated and comparisons between Class I and Class III groups were made. In addition, the height of orthodontic patients was indirectly compared with that of the general population. RESULTS: In boys and girls, height completion rate was >90% at SMI 6, residual height was fewer than 10 cm at SMI 7, and height increase per sequential SMI stage was greatest from SMI 6 to SMI 7. Height velocity was greatest from SMI 5 to SMI 6 in boys and from SMI 4 to SMI 5 in girls. CONCLUSIONS: There was no significant difference in body height parameters for all SMI stages between Class I and Class III adolescents. Adolescents who had orthodontic treatment were not shorter in stature at growth completion compared with the general population.
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Estatura , Maloclusión de Angle Clase III/terapia , Maloclusión Clase II de Angle/terapia , Ortodoncia Correctiva , Adolescente , Determinación de la Edad por el Esqueleto , Desarrollo Óseo , Niño , Femenino , Gráficos de Crecimiento , Mano/diagnóstico por imagen , Mano/crecimiento & desarrollo , Huesos de la Mano/diagnóstico por imagen , Huesos de la Mano/crecimiento & desarrollo , Humanos , Estudios Longitudinales , Masculino , Radiografía , República de Corea , Estudios Retrospectivos , Factores Sexuales , Muñeca/diagnóstico por imagen , Muñeca/crecimiento & desarrolloRESUMEN
The relationship between the length of the second and fourth ring finger (2D:4D ratio) is a sexually dimorphic trait, higher in females than in males. It is established during early prenatal development under the influence of sex hormones, as demonstrated in numerous studies both in humans and in mice. The current study involves patients with congenital GH/IGF-1 deficiency, a population not yet investigated. The 2D:4D ratio was measured from hand x-rays and compared with normal hand x-rays taken from the Greulich & Pyle Atlas. The analyses of our results revealed that patients with congenital GH/IGF-1 deficiency show an identical 2D:4D ratio for both sexes, but a higher (more feminine) ratio than the normal population. These findings may be explained by a higher estrogen effect resulting from the absence of a functional GH-IGF-1 axis prenatally.
Asunto(s)
Factor I del Crecimiento Similar a la Insulina , Caracteres Sexuales , Animales , Femenino , Dedos/crecimiento & desarrollo , Mano/crecimiento & desarrollo , Humanos , Factor I del Crecimiento Similar a la Insulina/deficiencia , Masculino , Ratones , Embarazo , RadiografíaRESUMEN
Whether the 1st segment of the human autopod 1st ray is a 'true' metapodial with loss of the proximal or mid phalanx or the original basal phalanx with loss of the metacarpal has been a long-lasting discussion. The actual knowledge of the developmental pattern of upper autopod segments at a fetal age of 20-22 weeks, combined with X-ray morphometry of normal long bones of the hand in the growing ages, was used for analysis of the parameters, percentage length, position of epiphyseal ossification centers and proximal/distal growth rate. The symmetric growth pattern in the fetal anlagen changed to unidirectional in the postnatal development in relation to epiphyseal ossification formation. The percentage length assessment, the distribution of the epiphyseal ossification centers, and differential proximal/distal growth rate among the growing hand segments supported homology of most proximal segment of the thumb with the 2nd-5th proximal phalanges and that of the proximal phalanx of the thumb with the 2nd-5th mid phalanges in the same hand. Published case reports of either metanalysis of 'triphalangeal thumb' and 'proximal/distal epiphyseal ossification centers' were used to support the applied morphometric methodology; in particular, the latter did not give evidence of growth pattern inversion of the proximal segment of the thumb. The presented data support the hypothesis that during evolution, the lost segment of the autopod 1st ray is the metacarpal.
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Mano/embriología , Mano/crecimiento & desarrollo , Huesos del Metacarpo/embriología , Huesos del Metacarpo/crecimiento & desarrollo , Adolescente , Niño , Preescolar , Humanos , LactanteRESUMEN
BACKGROUND: The aims of the study were (1) to assess hand sensibility in healthy young children using instruments validated for adults; (2) to identify which test tools are suitable; and (3) to compare the dominant and nondominant sides. METHODS: Twenty-five healthy children aged seven to 11 years (meanâ¯=â¯9.5 years) were investigated. Sensibility was assessed with the Semmes-Weinstein monofilament test, two-point discrimination, localization test, and stereognosis object recognition. RESULTS: The thinnest Semmes-Weinstein filament (Dâ¯=â¯2.83 mm) was felt at 94% of examined points. A two-point discrimination at the smallest distance of 2 mm was found in the thumb in 84% of children and in the index finger in 94%. Only 60% felt this distance in the fifth digit. The difference between little finger and index finger was statistically significant. Near-maximum value on the localization test was scored in both hands. All children had a 100% score for both hands in the stereognosis object recognition. CONCLUSIONS: Most children can detect touch in the digits at low pressure. The majority are able to discern two points 2 mm apart in the first and second digits, but significantly less so in the fifth digit. Children are well able to localize on which side of a fingertip pressure is applied. Objects are recognized well. There appear to be no differences between the dominant and nondominant hands in either test. Adjustment of sensory test protocols routinely used in adults is necessary to optimize hand sensation testing in children, in view of the detection limits.
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Mano , Tacto , Niño , Mano/crecimiento & desarrollo , Mano/fisiología , Humanos , Detección de Señal Psicológica , Tacto/fisiologíaRESUMEN
The length ratio of the second to the fourth finger (2D:4D) is a possible biomarker of prenatal sex hormone levels, which play a significant role in determining the sex-related body traits. The aim of this study was to assess the association between the 2D:4D ratio and morphological characteristics, related to sexual dimorphism. We analyzed a group of Russian males (N = 169) and females (N = 193) aged between 17 and 27 years (with mean ages of 18.6±1.50 and 18.9±1.85, respectively) for the association between the 2D:4D ratio and a wide range of morphological characteristics, some of which were considered in this aspect for the first time. The 2D:4D ratio in males was significantly lower than in females (p ˂ 0.000). A highly statistically significant correlation was found between 2D:4D and sexually dimorphic morphological traits in the total sample. The association of 2D:4D ratio with morphological signs of masculinity/femininity within male and female samples were revealed only as a trend, which was more distinct for the functional indicators (handgrip strength)
No disponible
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto Joven , Adulto , Dedos/anatomía & histología , Caracteres Sexuales , Mano/crecimiento & desarrollo , Desarrollo Fetal/fisiología , Testosterona , Federación de Rusia , Identidad de Género , Pesos y Medidas Corporales/métodos , Fuerza de la ManoRESUMEN
Functional lateralization can be an indicator of brain maturation. We have consistently shown that, in the adult brain, proprioceptive processing of muscle spindle afferents generating illusory movement of the right hand activates inferior frontoparietal cortical regions in a right-side dominant manner in addition to the cerebrocerebellar motor network. Here we provide novel evidence regarding the development of the right-dominant use of the inferior frontoparietal cortical regions in humans using this task. We studied brain activity using functional magnetic resonance imaging while 60 right-handed blindfolded healthy children (8-11 years), adolescents (12-15 years), and young adults (18-23 years) (20 per group) experienced the illusion. Adult-like right-dominant use of the inferior parietal lobule (IPL) was observed in adolescents, while children used the IPL bilaterally. In contrast, adult-like lateralized cerebrocerebellar motor activation patterns were already observable in children. The right-side dominance progresses during adolescence along with the suppression of the left-sided IPL activity that emerges during childhood. Therefore, the neuronal processing implemented in the adult's right IPL during the proprioceptive illusion task is likely mediated bilaterally during childhood, and then becomes right-lateralized during adolescence at a substantially later time than the lateralized use of the cerebrocerebellar motor system for kinesthetic processing.
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Lateralidad Funcional/fisiología , Ilusiones/fisiología , Lóbulo Parietal/crecimiento & desarrollo , Lóbulo Parietal/fisiología , Propiocepción/fisiología , Adolescente , Mapeo Encefálico , Niño , Femenino , Mano/crecimiento & desarrollo , Mano/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Movimiento/fisiología , Lóbulo Parietal/diagnóstico por imagen , Estimulación Física , Psicofísica , Vibración , Adulto JovenRESUMEN
In this article, the author surveys the best available evidence to guide decision-making in pediatric burn reconstruction. Evidence-based protocols are examined in the context of optimizing form and function in children who have sustained burn injury.
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Quemaduras/cirugía , Procedimientos de Cirugía Plástica , Axila/lesiones , Axila/cirugía , Desarrollo Óseo , Mama/crecimiento & desarrollo , Mama/lesiones , Mama/cirugía , Niño , Cicatriz/cirugía , Contractura/etiología , Contractura/cirugía , Traumatismos Faciales/cirugía , Mano/crecimiento & desarrollo , Traumatismos de la Mano/cirugía , Humanos , Terapia por Láser , Desarrollo Maxilofacial , Cuidados Preoperatorios , Rango del Movimiento Articular , Piel/crecimiento & desarrollo , Piel/lesiones , Colgajos Quirúrgicos , Expansión de TejidoRESUMEN
Congenital hand malformations are rare, but hand function and aesthetics cannot be improved by surgery in every affected child. However, whenever this is possible, it is important to create an individual surgical plan for each child. Growth has to be taken into account in the accurate planning of incisions and local flaps. Just because it is technically possible, not every flap should be used in the malformed child's hand. In the following article, we present a collection of reliable flaps in the surgery of the congenitally malformed hand.
Asunto(s)
Deformidades Congénitas de la Mano/cirugía , Colgajos Quirúrgicos/cirugía , Niño , Estética , Mano/crecimiento & desarrollo , Mano/cirugía , Humanos , Comunicación Interdisciplinaria , Colaboración Intersectorial , Destreza Motora , Planificación de Atención al Paciente , Pronóstico , Herida QuirúrgicaRESUMEN
PURPOSE: We aimed to establish a practical method to evaluate skeletal age using cervical vertebrae. METHODS: The study consisted of hand-wrist and cephalometric radiographs of 324 subjects (167 girls, 157 boys; age range, 7.3-17.2 years). Skeletal ages of the subjects were calculated from hand-wrist radiographs, and cervical vertebral bodies were measured using cephalometric radiographs. A single formula based on C3 and C4 vertebral body heights with different coefficients for each gender was derived using ridge regression analysis. RESULTS: The correlation coefficients for vertebral and hand-wrist bone age were 0.825 and 0.856 for girls and boys, respectively. The correlations among vertebral bone age and C3 and C4 vertebral body heights were also found to be significant. The intraclass correlation (ICC) score was found to be 0.914, which shows high consistency between the two measurements of the same investigator for each C3 and C4 vertebral body height result. CONCLUSION: The formula derived for evaluating skeletal age in cephalometric radiographs is reliable and can be applied to both girl and boy subjects for legal requirements or therapeutic needs of age estimation.
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Determinación de la Edad por el Esqueleto/métodos , Cefalometría/instrumentación , Vértebras Cervicales/crecimiento & desarrollo , Mano/crecimiento & desarrollo , Articulación de la Muñeca/crecimiento & desarrollo , Muñeca/crecimiento & desarrollo , Adolescente , Cefalometría/métodos , Vértebras Cervicales/anatomía & histología , Vértebras Cervicales/diagnóstico por imagen , Niño , Femenino , Mano/diagnóstico por imagen , Humanos , Masculino , Reproducibilidad de los Resultados , Estudios Retrospectivos , Muñeca/diagnóstico por imagen , Articulación de la Muñeca/diagnóstico por imagenRESUMEN
Background: Stature is a significant anthropometric determinant of the physical identity of an individual. Aim: This study was carried out to estimate stature of Nigerian Annang indigenes of Akwa Ibom State from hand and foot dimensions. Methods: Two hundred (200) adults Annang indigenes (100male and female each) were randomly selected for this study. Hand and foot dimensions were obtained by direct linear measurements using a 150mm digital vernier caliper (with accuracy of 0.01mm); while stature was determined by stadiometric measurement of the height (to the nearest 0.1m). Measurements obtained include; second (2D), fourth digit (4D) and right foot length (RFL). All measurement were converted to centimeters (cm). SPSS (IBM® version 20, Armonk, New York, USA) t-test was to evaluate gender difference in the measured dimensions; while Pearson's correlation and Generalized Linear Modeling were used to derive Regression equation for estimation of stature from the measured dimensions. The significance level was set at 95% as Pâ¤0.05 was considered significant. Results: The t-test showed that males displayed significantly higher mean values than the females for all measured parameters (P<0.001). Single regression sex specific regression formulae were derived and the result showed that better prediction (r) values were obtained for females F (2D=0.428, 4D=0.430, RFL=0.587; P<0.01) population when compared to males M (2D=0.319, 4D=0.231, RFL=0.456 P<0.05). Conclusion: This study suggests the existence of sexual difference in hand and foot dimension and also the possibility of accurately estimating stature from the right foot length, right second and fourth digit
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Estatura , Pie/crecimiento & desarrollo , Mano/crecimiento & desarrollo , NigeriaRESUMEN
Falling on the outstretched hands (FOOSH), a protective mechanism to arrest the body and avoid injury, requires upper limb and trunk motor control for effective body descent. The purpose of this study was to investigate muscle activity during three phases of an unexpected FOOSH in healthy older and younger women. Twenty young (mean age 22.9yrs, SD±3.7) and 20 older females (mean age 68.1yrs, SD±5.0) performed five trials of unexpected FOOSHs. Surface electromyography (EMG) determined muscle activations for left shoulder girdle, elbow and abdominal muscles during an unexpected FOOSH. Root mean squared EMG data were calculated during three phases: (1) baseline (BL; 500msprior to release), (2) the preparatory phase (PRE; time between release and impact) (mean 257±37ms) and post-impact (POST; 200msafter impact). A mixed MANOVA determined differences between phases and age groups. There was a significant multivariate interaction effect of age and time phase on muscle activity (p=0.001). Younger women had significantly higher internal oblique/transversus abdominus activity during PRE (p=0.006) as well as variations in muscle activity of shoulder girdle and elbow muscles. The age differences observed may lead to poorer preliminary trunk activation and greater arm bracing in older women, potentially increasing risk of fallrelated injury.
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Accidentes por Caídas , Envejecimiento/fisiología , Mano/fisiología , Músculo Esquelético/fisiología , Torso/fisiología , Adolescente , Adulto , Anciano , Fenómenos Biomecánicos , Electromiografía , Femenino , Mano/crecimiento & desarrollo , Humanos , Persona de Mediana Edad , Músculo Esquelético/crecimiento & desarrollo , Equilibrio Postural , Torso/crecimiento & desarrolloRESUMEN
Bone (skeletal) age determination is the simplest and most used index for the assessment of developmental and physiological age in healthy children and those with growth disorders. At present the test is done by manual or automated reading of the hand and wrist X-rays, necessitating two visits by the child: to the pediatrician and radiology departments. A newly developed simple quantitative ultrasound technique (QUST) using several hand and wrist bones, which can be performed in the pediatrician's office could combine the child's growth and biological age evaluation in one visit.
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Determinación de la Edad por el Esqueleto/métodos , Determinación de la Edad por el Esqueleto/normas , Adolescente , Desarrollo Óseo , Niño , Preescolar , Etnicidad , Femenino , Mano/diagnóstico por imagen , Mano/crecimiento & desarrollo , Humanos , Lactante , Recién Nacido , Masculino , Ultrasonografía , Muñeca/diagnóstico por imagen , Muñeca/crecimiento & desarrollo , Adulto JovenRESUMEN
El manejo del eczema de manos es complejo, ya que engloba eczemas de etiopatogenia, curso y pronóstico muy diferentes; la mayoría de tratamientos disponibles no cuentan con niveles de eficacia establecidos, y en sus formas graves la calidad de vida se afecta de forma importante. La educación del paciente, las medidas de protección y el uso de emolientes constituyen un pilar fundamental en el abordaje de estos pacientes. Los corticoides tópicos de alta potencia son el tratamiento de elección, seguidos de los inhibidores de la calcineurina para el mantenimiento de la enfermedad. En los casos refractarios a estos tratamientos deberíamos utilizar la fototerapia o tratamientos sistémicos, los cuales no deberían demorarse para evitar sensibilizaciones, bajas laborales y alteración en la calidad de vida. La alitretinoína es el único tratamiento oral disponible que ha sido aprobado para su utilización en el eczema crónico de manos
Management of hand eczema is complex because of the broad range of different pathogeneses, courses, and prognoses. Furthermore, the efficacy of most available treatments is not well established and the more severe forms can have a major impact on the patient's quality of life. Patient education, preventive measures, and the use of emollients are the mainstays in the management of hand eczema. High-potency topical corticosteroids are the treatment of choice, with calcineurin inhibitors used for maintenance. Phototherapy or systemic treatments are indicated in patients who do not respond to topical treatments. Switching from topical treatments should not be delayed to avoid sensitizations, time off work, and a negative impact on quality of life. Alitretinoin is the only oral treatment approved for use in chronic hand eczema
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Femenino , Humanos , Masculino , Eccema/metabolismo , Eccema/patología , Mano/patología , /normas , Calcineurina/provisión & distribución , Terapéutica/métodos , Calidad de Vida/psicología , Prevención Primaria/métodos , Prevención Secundaria/educación , Prevención Terciaria/métodos , Eccema/diagnóstico , Mano/crecimiento & desarrollo , Calcineurina/uso terapéutico , Terapéutica/tendencias , Terapéutica , Calidad de Vida/legislación & jurisprudencia , Prevención Primaria , Prevención Secundaria/normas , Prevención Terciaria , Educación del Paciente como Asunto/clasificaciónRESUMEN
BACKGROUND: Age estimation of individuals is important in human biology and has various medical and forensic applications. Recent interest in MR-based methods aims to investigate alternatives for established methods involving ionising radiation. Automatic, software-based methods additionally promise improved estimation objectivity. AIM: To investigate how informative automatically selected image features are regarding their ability to discriminate age, by exploring a recently proposed software-based age estimation method for MR images of the left hand and wrist. SUBJECTS AND METHODS: One hundred and two MR datasets of left hand images are used to evaluate age estimation performance, consisting of bone and epiphyseal gap volume localisation, computation of one age regression model per bone mapping image features to age and fusion of individual bone age predictions to a final age estimate. RESULTS: Quantitative results of the software-based method show an age estimation performance with a mean absolute difference of 0.85 years (SD = 0.58 years) to chronological age, as determined by a cross-validation experiment. Qualitatively, it is demonstrated how feature selection works and which image features of skeletal maturation are automatically chosen to model the non-linear regression function. CONCLUSION: Feasibility of automatic age estimation based on MRI data is shown and selected image features are found to be informative for describing anatomical changes during physical maturation in male adolescents.
Asunto(s)
Determinación de la Edad por el Esqueleto/métodos , Mano/crecimiento & desarrollo , Aprendizaje Automático , Imagen por Resonancia Magnética , Muñeca/crecimiento & desarrollo , Adolescente , Austria , Humanos , Masculino , Programas Informáticos , Adulto JovenRESUMEN
BACKGROUND: Diffusion tensor imaging (DTI) has expanded our knowledge of corticospinal tract (CST) anatomy and development. However, previous developmental DTI studies assessed the CST as a whole, overlooking potential differences in development of its components related to control of the upper and lower extremities. The present cross-sectional study investigated age-related changes, side and gender differences in streamline volume of the leg- and hand-related segments of the CST in children. SUBJECTS AND METHODS: DTI data of 31 children (1-14 years; mean age: 6±4 years; 17 girls) with normal conventional MRI were analyzed. Leg- and hand-related CST streamline volumes were quantified separately, using a recently validated novel tractography approach. CST streamline volumes on both sides were compared between genders and correlated with age. RESULTS: Higher absolute streamline volumes were found in the left leg-related CST compared to the right (p=0.001) without a gender effect (p=0.4), whereas no differences were found in the absolute hand-related CST volumes (p>0.4). CST leg-related streamline volumes, normalized to hemispheric white matter volumes, declined with age in the right hemisphere only (R=-.51; p=0.004). Absolute leg-related CST streamline volumes showed similar, but slightly weaker correlations. Hand-related absolute or normalized CST streamline volumes showed no age-related variations on either side. CONCLUSION: These results suggest differential development of CST segments controlling hand vs. leg movements. Asymmetric volume changes in the lower limb motor pathway may be secondary to gradually strengthening left hemispheric dominance and is consistent with previous data suggesting that footedness is a better predictor of hemispheric lateralization than handedness.
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Imagen de Difusión Tensora/métodos , Pierna , Actividad Motora , Tractos Piramidales/anatomía & histología , Tractos Piramidales/crecimiento & desarrollo , Adolescente , Niño , Desarrollo Infantil , Preescolar , Femenino , Lateralidad Funcional , Mano/crecimiento & desarrollo , Mano/fisiología , Humanos , Lactante , Pierna/crecimiento & desarrollo , Pierna/fisiología , Imagen por Resonancia Magnética , Masculino , Actividad Motora/fisiología , Tamaño de los Órganos , Tractos Piramidales/fisiología , Caracteres Sexuales , Sustancia Blanca/anatomía & histología , Sustancia Blanca/crecimiento & desarrollo , Sustancia Blanca/fisiologíaRESUMEN
To act on the environment, organisms must perceive object locations in relation to their body. Several neuroscientific studies provide evidence of neural circuits that selectively represent space within reach (i.e., peripersonal) and space outside of reach (i.e., extrapersonal). However, the developmental emergence of these space representations remains largely unexplored. We investigated the development of space coding in infant macaques and found that they exhibit different motor strategies and hand configurations depending on the objects' size and location. Reaching-grasping improved from 2 to 4 weeks of age, suggesting a broadly defined perceptual body schema at birth, modified by the acquisition and refinement of motor skills through early sensorimotor experience, enabling the development of a mature capacity for coding space.
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Imagen Corporal , Espacio Personal , Desempeño Psicomotor/fisiología , Percepción Espacial/fisiología , Factores de Edad , Animales , Animales Recién Nacidos , Femenino , Mano/crecimiento & desarrollo , Fuerza de la Mano/fisiología , Macaca mulatta , Masculino , Tiempo de Reacción/fisiologíaRESUMEN
Este estudo analisou a aplicabilidade da Fórmula de Regressão Múltipla de Mito, Sato e Mitani (2002) na avaliação da maturidade esquelética em 289 crianças brasileiras, naturais da cidade de Ourinhos, com a idade cronológica variando entre sete e 15 anos, sendo 153 do sexo feminino e 136 do sexo masculino. Na sequência, comparou-se a idade esquelética verificada na vértebra cervical com a identificada na radiografia carpal, empregando-se o método computadorizado de Eklõf e Ringertz (1967), e o método comparativo de Greulich e Pyle (1959). Com a aplicação do teste t e da análise de correlação, e considerando a metodologia adotada, concluiu-se que: 1) para o sexo feminino, observou-se uma maior correlação entre a idade ER e a idade GP; com relação à idade das vértebras, a correlação foi significante com a idade GP, ao passo que, no sexo masculino, verificou-se a diferença entre a idade vertebral e as demais; 2) o resultado das proporções mostrou-se semelhante ao de Mito, Sato e Mitani, para o sexo feminino; 3) a morfologia das vértebras apresentou maior correlação com o metacarpo do segundo dedo; 4) a fórmula de regressão não foi aplicável à amostra avaliada, devendo ser individualizada segundo a composição racial.
This study verified the applicability of the Multiple Regression Formula of Mito, Sato and Mitani (2002) in the assessment of skeletal maturity in 289 Brazilian children that were born in Ourinhos, with chronological ages ranging from 7-15 years, of which 153 were of the female gender and 136 of the male gender. Next, we compared the skeletal age checking the cervical vertebrae with the carpal index on radiographs, using the computerized method of the Eklõf Ringertz (1967), and the comparative method of Greulich and Pyle (1959). The application of the test t and correlation analysis, considering the methodology, it can be concluded that: 1) children of the female gender, showed a higher correlation between ER and GP age; with the vertebrae age, the correlation was significant, with the GP age; however in children of the male gender, it was verified a difference between the vertebral age with the others; 2) the result of the proportions was similar to the Mito, Sato and Mitani, for females; 3) the morphology of the vertebrae showed a higher correlation with the second finger metacarpal; 4) the regression formula was not applicable to the assessed sample and should be individualized according to racial composition.