背包类型对大学生楼梯行走运动学和足底压力的影响

目的 分析不同背包类型和载荷对大学生上楼梯行走时运动学和足底压力的影响,为大学生选择合适的背包及携带方式提供参考。方法 采用Nokov红外光点运动捕捉系统和Podomed足底压力测试系统分析15名男大学生上楼梯支撑期内躯干和下肢关节活动范围、峰值时刻下肢运动学参数、足底各分区压力峰值、接触时间、全足最大压强、平均压强等参数的差异。结果 5%BW和10%BW背包载荷会减小躯干旋转活动范围(range of motion, ROM),增加踝关节屈伸和内外翻ROM,10%BW背包载荷下足底第1、3跖骨压力峰值和全足最大压强提升(P<0.05)。单肩包和手提包减小躯干侧倾和旋转ROM,增大了踝关节屈伸ROM、髋关节屈曲角、足弓和足跟内侧压力峰值(P<0.05)。双肩包负重增加足趾区的压力峰值(P<0.05)。结论 楼梯行走时,5%BW和10%BW背包载荷均会限制躯干旋转,增加踝关节ROM,10%BW载荷还会增加足跖区的负荷。单侧负重模式会使躯干向未负重侧倾斜以及向负重侧旋转。携带双肩包时足趾处的压力较高,而单肩包和手提包主要集中增加足弓和足跟内侧压力。建议大学生群体选择对称性...     

Writing without Graphic Motor Patterns: A Case of Dysgraphia for Letters and Digits Sparing Shorthand Writing

This paper reports the case of a patient HP who presents a dysgraphia affecting the production of letters and digits while sparing shorthand writing. HP's writing impairmentis two-fold. On one hand, HP produces systematic lettersubstitutions affecting exclusively lower-case letters b, p, d, and q. Such confusions are also observed in tasks assessing the mental imagery of letters and the processing of visually presented, isolated letters. This deficit is attributed to a circumscribed disruption of allographic representations. On the other hand, HP can write correctly formed letters and digits but the production of these symbols is slow and nonfluent. This disturbance was investigated by using a digitising tablet to record movements performed in grapho-motor production. The results of the analysis of temporal and kinematic indices suggest that graphic motor patterns of letters and digits are no longer available to this patient, whereas motor patterns underlying the production of shorthand seem unaffected. Itis suggested thatthere are two ways forproducing spatially well-formed symbols. One route is mediated by graphic motor patterns and the other by a motor planning system that would be used in other tasks involving the generation of 2D trajectories as in drawing or in tracing unfamiliar symbols.     

Stimulus-Specific Patterns of Cardiovascular Reactivity in Type A and B Subjects: Evidence for Enhanced Vagal Reactivity in Type B

Recent evidence suggests that the differences in cardiovascular reactivity between individuals exhibiting the Type A behavior pattern and those that do not are not limited to excessive betaadrenergic reactivity in Type A's. Research also suggests the possibility of a tendency for enhanced alpha-adrenergically and vagally mediated cardiovascular reactivity in Type B's. In the present study, Type A and Type B subjects were exposed to stressor stimuli known to elicit either betaadrenergic or alpha-adrenergic and vagal responses in the cardiovascular system. Heart rate, blood pressure, and forearm blood flow and vascular resistance responses were measured. The two Types did not differ in response to the beta-adrenergic stimulus (mental arithmetic). However, the alpha-adrenergic/vagal stimulus (cold face stimulus) produced more prolonged heart rate and blood flow responses in Type B subjects. Results suggest that Type B's show hyperreactivity (compared to Type A) when alpha-adrenergic or vagal cardiovascular responses are elicited. The nature of this hyperreactivity suggests possible mechanisms for reduced cardiovascular disease risk in Type B individuals.     

Neuropsychological Significance of Variations in Patterns of Academic Performance: Motor, Psychomotor, and Tactile-Perceptual Abilities

Forty-five 9 to 14-year-old children with learning disabilitieswhose WISC Full Scale IQs fell within the 86–114 rangewere divided into 3 groups on the basis of their patterns ofreading, spelling, and arithmetic achievement. Group 1 was composedof children who were uiformly deficient in reading, spelling,and arithmetic; children in Group 2 were relatively adept atarithmetic as compared to their performance in reading and spelling;Group 3 was composed of children whose reading and spellingperformances were average or above, but whose arithmetic performancewas relatively deficient. The performances of these childrenwere compared on 13 dependent measures, including tests formotor. psychomotor, and tactile-perceptual abilities. Group3 was found to be generally deficient on the more complex, heterogenouspsychomotor measures and on a composite tactile-perceptual measure.The results are discussed with referrence to (a) the neuropsychologicalabilities which mey limit performance on calculation tasks,(b) problems with the exclusive use of the "level of performance"approach to the investigation of children with arithmetic disabilities,and (c) some remedial educational implications of the differentialpatterns of abilities and deficits exhibited by such children.     

In Vivo 3D Analysis of Thoracic Kinematics: Changes in Size and Shape During Breathing and Their Implications for Respiratory Function in Recent Humans and Fossil Hominins

The human ribcage expands and contracts during respiration as a result of the interaction between the morphology of the ribs, the costo‐vertebral articulations and respiratory muscles. Variations in these factors are said to produce differences in the kinematics of the upper thorax and the lower thorax, but the extent and nature of any such differences and their functional implications have not yet been quantified. Applying geometric morphometrics we measured 402 three‐dimensional (3D) landmarks and semilandmarks of 3D models built from computed tomographic scans of thoraces of 20 healthy adult subjects in maximal forced inspiration (FI) and expiration (FE). We addressed the hypothesis that upper and lower parts of the ribcage differ in kinematics and compared different models of functional compartmentalization. During inspiration the thorax superior to the level of the sixth ribs undergoes antero‐posterior expansion that differs significantly from the medio‐lateral expansion characteristic of the thorax below this level. This supports previous suggestions for dividing the thorax into a pulmonary and diaphragmatic part. While both compartments differed significantly in mean size and shape during FE and FI the size changes in the lower compartment were significantly larger. Additionally, for the same degree of kinematic shape change, the pulmonary thorax changes less in size than the diaphragmatic thorax. Therefore, variations in the form and function of the diaphragmatic thorax will have a strong impact on respiratory function. This has important implications for interpreting differences in thorax shape in terms of respiratory functional differences within and among recent humans and fossil hominins. Anat Rec, 300:255–264, 2017. © 2016 Wiley Periodicals, Inc.     

The Role of the Supplementary Motor Region in Overt Reading: Evidence for Differential Processing in SMA-Proper and Pre-SMA as a Function of Task Demands

A differentiation in function between the pre-SMA (i.e., cognitive load) and the SMA-proper (i.e., motor execution) has been described (Zhang et al., Cereb Cortex 22:99–111, 2012). These differential SMA functions may be influential in overt reading tasks. The present study examined the relationships between various segments of the SMA and overt reading through the modulation of task demands in an effort to explore the complexity of the print-to-speech network. Skilled reading adults (N?=?15) took part in five overt reading tasks: pure regular word reading, pure exception word reading, mixed regular word and exception word reading, go/no-go reading with nonword foils and go/no-go reading with pseudohomophone foils. Five regions of interest that spanned the pre-SMA to the SMA-proper were isolated. Behaviour-function relationships were tested to examine the associations between performance (response time) and brain activity (percent signal change). Further, the coherence between feedforward (SMA) and feedback (supramarginal gyrus) regions were explored to further refine the print-to-speech network. We found that the pre-SMA was related to cognitively demanding tasks (go/no-go with pseudohomophones), whereas the SMA-proper was related to an automatized task (pure regular words). Notably, only those tasks that required information from the feedback system (i.e., mixed word lists, go/no-go tasks) showed connections between SMA regions and the supramarginal gyrus, which is in line with the role of feedback and feedforward systems in the print-to-speech network. Together, these results support the notion that the pre-SMA and SMA-proper are sensitive to reading tasks that differentially invoke higher cognitive resources (mixed word lists, go/no-go) versus automatized articulation (pure lists), respectively. We discuss our findings in the context of print-to-speech neural networks.     

Vascular Patterns in the Heads of Dinosaurs: Evidence for Blood Vessels,Sites of Thermal Exchange,and Their Role in Physiological Thermoregulatory Strategies

Body size has thermal repercussions that impact physiology. Large-bodied dinosaurs potentially retained heat to the point of reaching dangerous levels, whereas small dinosaurs shed heat relatively easily. Elevated body temperatures are known to have an adverse influence on neurosensory tissues and require physiological mechanisms for selective brain and eye temperature regulation. Vascular osteological correlates in fossil dinosaur skulls from multiple clades representing different body-size classes were identified and compared. Neurovascular canals were identified that differentiate thermoregulatory strategies involving three sites of evaporative cooling that are known in extant diapsids to function in selective brain temperature regulation. Small dinosaurs showed similarly sized canals, reflecting a plesiomorphic balanced pattern of blood supply and a distributed thermoregulatory strategy with little evidence of enhancement of any sites of thermal exchange. Large dinosaurs, however, showed a more unbalanced vascular pattern whereby certain sites of thermal exchange were emphasized for enhanced blood flow, reflecting a more focused thermal strategy. A quantitative, statistical analysis of canal cross-sectional area was conducted to test these anatomical results, confirming that large-bodied, and often large-headed, species showed focused thermal strategies with enhanced collateral blood flow to certain sites of heat exchange. Large theropods showed evidence for a plesiomorphic balanced blood flow pattern, yet evidence for vascularization of the large antorbital paranasal air sinus indicates theropods may have had a fourth site of heat exchange as part of a novel focused thermoregulatory strategy. Evidence presented here for differing thermoregulatory strategies based on size and phylogeny helps refine our knowledge of dinosaur physiology. Anat Rec, 303:1075–1103, 2020. © 2019 American Association for Anatomy