Biomechanics of the tarsal mechanism. A key to the function of the normal human foot

2000 ◽  
Vol 90 (1) ◽  
pp. 12-17 ◽  
Author(s):  
A Huson
Keyword(s):  
Joint Function ◽  
Tarsal Joint ◽  
Human Foot ◽  
Normal Human ◽  
Midtarsal Joint ◽  
The Relationship

This article describes the function of the tarsal complex as a constrained mechanism. The relationship between the interdependence of the motions of the tarsal joints and the special nature of tarsal joint function is explained, with emphasis on the midtarsal joint and its presumed two axes of motion.

Difference in Attachment of the Tensor Veli Palatini Muscle to the Eustachian Tube Cartilage with Age

2003 ◽  
Vol 112 (5) ◽  
pp. 439-443 ◽  
Author(s):  
Chiaki Suzuki ◽  
Isamu Sando ◽  
Miwa Kitagawa ◽  
Carey D. Balaban ◽  
Kenji Takasaki
Keyword(s):  
Eustachian Tube ◽  
Later Life ◽  
Measurement Methods ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Tensor Veli Palatini Muscle ◽  
Normal Human ◽  
Development And Aging ◽  
Temporal Bones ◽  
The Relationship

To test a hypothesis that ventilation of the eustachian tube (ET) varies with age, we investigated the relationship between age and the attachment of the tensor veli palatini muscle (TVPM) to the lateral lamina of the ET cartilage in 12 normal human temporal bones obtained from individuals 3 months to 81 years old. We used computer-aided 3-dimensional reconstruction and measurement methods. We found that the length of the TVPM attachment and its ratio to the length of the ET, especially that of the cartilaginous portion of the ET, increases with age from infancy to adulthood, and decreases with age from young adulthood to later life. These findings are thought to be related to postnatal development and aging. The possibility of differences in ventilation function with age is discussed.

Modelling the relationship between maternal blood flow and villus tree density in normal human pregnancy

Placenta ◽  
2015 ◽  
Vol 36 (9) ◽  
pp. A13-A14
Author(s):  
Rojan Saghian ◽  
Joanna James ◽  
Sally L. Collins ◽  
Merryn Tawhai ◽  
Alys R. Clark
Keyword(s):  
Blood Flow ◽  
Maternal Blood ◽  
Tree Density ◽  
Human Pregnancy ◽  
Normal Human ◽  
The Relationship

scholarly journals Siderocytes in mammalian blood

1946 ◽  
Vol 133 (872) ◽  
pp. 235-248 ◽  
Keyword(s):  
Clinical Medicine ◽  
Close Correlation ◽  
Bile Pigment ◽  
Pigment Formation ◽  
Adverse Conditions ◽  
Large Numbers ◽  
Mammalian Blood ◽  
Normal Human ◽  
Relationship Of ◽  
The Relationship

Since a review of the conditions under which siderocytes appear will support a hypothesis that it is an ageing erythrocyte at least as strongly as Grüneberg’s (1941 a ) theory that it should be considered as a young cell, a search was made in blood films of stored mammalian blood and large numbers of siderocytes were found. The conditions affecting the rate of appearance of the siderocytes were studied, and it was found that adverse conditions would hasten their appearance. The relationship of the siderotic material to the 'easily split’ blood iron was also considered, and it seems probable that both are derived from a special and identical fraction of ‘haemoglobin’, and that this phenomenon is related to an intracorpuscular bile pigment formation. The occurrence of siderocytosis after the ingestion of acetyl phenylhydrazine by a ‘normal’ human being was followed, and a close correlation between siderocytosis, erythrocyte destruction and urinary siderosis as described by Peyton Rous (1918) is shown. The siderocyte extrudes its siderotic granules and reverts to a state at present morphologically indistinguishable from the normal erythrocyte, but appears to be susceptible of phagocytosis at this stage. The application of siderocyte counts to clinical medicine is suggested.

scholarly journals Sensitivity and Specificity of the Functional Hallux Limitus Test to Predict Foot Function

2002 ◽  
Vol 92 (5) ◽  
pp. 269-271 ◽  
Author(s):  
Craig Payne ◽  
Vivienne Chuter ◽  
Kathryn Miller
Keyword(s):  
Sensitivity And Specificity ◽  
Metatarsophalangeal Joint ◽  
Clinical Test ◽  
Joint Function ◽  
Compensatory Mechanisms ◽  
First Metatarsophalangeal Joint ◽  
Hallux Limitus ◽  
First Ray ◽  
Foot Function ◽  
Midtarsal Joint

Functional hallux limitus is an underrecognized entity that generally does not produce symptoms but can result in a variety of compensatory mechanisms that can produce symptoms. Clinically, hallux limitus can be determined by assessing the range of motion available at the first metatarsophalangeal joint while the first ray is prevented from plantarflexing. The aim of this study was to determine the sensitivity and specificity of this clinical test to predict abnormal excessive midtarsal joint function during gait. A total of 86 feet were examined for functional hallux limitus and abnormal pronation of the midtarsal joint during late midstance. The test had a sensitivity of 0.72 and a specificity of 0.66, suggesting that clinicians should consider functional hallux limitus when there is late midstance pronation of the midtarsal joint during gait. (J Am Podiatr Med Assoc 92(5): 269-271, 2002)

Chronogenetics. Its Foundations, Scope, and Impact

1974 ◽  
Vol 23 (S1) ◽  
pp. 131-143
Author(s):  
L. Gedda ◽  
G. Brenci
Keyword(s):  
Preventive Medicine ◽  
Animal Species ◽  
Higher Plants ◽  
Cosmic Time ◽  
Future Perspective ◽  
Fourth Dimension ◽  
Biological Time ◽  
Normal Human ◽  
Object Of Study ◽  
The Relationship

Many chronological correlations in different plant and animal species, in populations, in human families, and between cotwins, prove the existence of characteristic biological times. Some such times also tend to be related to cosmic time, in which they develop and from which they are induced, resulting in peculiar composite times, such as the daily, monthly, or annual rhythms, that are the object of study of chronobiology.Beyond these examples of exogenous chronological induction, the existence of a hereditary biological time is postulated, as the basic phenomenon in the relationship between time and life. The newborn scientific branch of “chronogenetics” is devoted to the study of the fundamental, endogenous genetic time, with its theoretical and practical, normal and pathologic implications. To explain and interpret the mechanisms of the hereditary biological time, the authors have developed a model based on the concepts of “ergon” (i.e., stability of the gene) and “chronon” (i.e., lifespan of the information). This Ergon/Chronon System is related to the gene, bringing into focus the fourth dimension and the dynamic aspects of unit of inheritance.The applications of chronogenetics extend to every expression of life, from the most primitive unicellular to the higher plants and animals. In the area of normal human traits, the study of the hereditary biological time contributes significantly to the interpretation of such phenomena as development, reproduction, homeostasis, and senescence. In the area of medicine, chronogenetics interpretes, unifies, and develops the temporal phenomena of inheritance. In a future perspective, chronogenetics appears to be fundamental for eugenics, preventive medicine, and prognosis.

Theory of mind and executive functions in normal human aging and Parkinson's disease

2000 ◽  
Vol 6 (7) ◽  
pp. 781-788 ◽  
Author(s):  
JENNIFER SALTZMAN ◽  
ESTHER STRAUSS ◽  
MICHAEL HUNTER ◽  
SARAH ARCHIBALD
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Theory Of Mind ◽  
Executive Functions ◽  
Right Hemisphere ◽  
Human Aging ◽  
Brain Functions ◽  
Normal Human ◽  
Relationship Of ◽  
The Relationship

Although the majority of research in theory of mind (TOM) has focused on young children or individuals with autism, recent investigations have begun to look at TOM throughout the lifespan and in other neurological and psychiatric populations. Some have suggested that TOM may represent a dissociable, modular brain system that is related to, but separable, from other brain functions including executive functions (EF). Recently, studies have shown that TOM performance can be compromised following an acquired brain insult (e.g, damage to the right hemisphere). However, the relationship of such impaired TOM performance to other brain functions in these cases has not been explored. This study investigated the effects of both normal human aging and Parkinson's disease on TOM. The relationship of TOM performance and EF in these groups was also examined. The results suggested that although TOM performance appeared compromised in the group of individuals with Parkinson's disease, the elderly control participants were relatively unimpaired relative to younger individuals. Significant relationships between several measures of TOM and EF were also found. The implications of these findings, and also the finding that failure on one measure of TOM did not necessarily predict failure on all measures of TOM, are discussed. (JINS, 2000, 6, 781–788.)

Analysis Techniques for Congruence of the Patellofemoral Joint

2009 ◽  
Vol 131 (12) ◽  
Author(s):  
K. D. Connolly ◽  
J. L. Ronsky ◽  
L. M. Westover ◽  
J. C. Küpper ◽  
R. Frayne
Keyword(s):  
Patellofemoral Joint ◽  
Contact Region ◽  
Mean Value ◽  
Knee Angle ◽  
Mr Images ◽  
Joint Function ◽  
Surface Representation ◽  
Local Measure ◽  
Joint Congruence ◽  
The Relationship

Quantifying joint congruence may help to understand the relationship between joint function and health. In previous studies, a congruence index (CI) has been used to define subject-specific joint congruence. However, the sensitivity of the CI algorithm to surface representation was unknown. The purpose of this study was to assess the effects of applying five modifications (M1–M5) to the CI algorithm to determine whether the magnitude and variability of the patellofemoral CI is dependent on the surface representation used. The five modifications focused on calculating the CI based on the principal curvature (M1) at the centroid of the contact region, (M2) using an root mean square value for the contact region, (M3) using a mean value for the contact region, (M4) using all digitized points of the patellar surface, and (M5) using all digitized points in contact. The CI found using the contact area (M1, M2, M3, and M5) provides a local measure for congruence, which was shown to increase (decreasing CI) with increasing joint angle. In ten healthy subjects measured with magnetic resonance (MR) images, the patellofemoral joint became significantly more congruent as the knee angle increased from 15 deg to 45 deg using method M5. The magnitude and variability of the patellofemoral CI was dependent on the surface representation used, suggesting that standardization of the surface representation is important to provide a consistent measure. Specifically, M5 provides a local measure of joint congruence, which can account for joint position and orientation. M5 balances the ability to detect differences in congruence between knee angles without introducing high variability.

scholarly journals Free moment induced by oblique transverse tarsal joint: investigation by constructive approach

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Tsung-Yuan Chen ◽  
Takahiro Kawakami ◽  
Naomichi Ogihara ◽  
Koh Hosoda
Keyword(s):  
Reaction Force ◽  
Axial Loading ◽  
Bipedal Walking ◽  
Transverse Motion ◽  
Constructive Approach ◽  
Tarsal Joint ◽  
Free Moments ◽  
Human Foot ◽  
Flexion Extension ◽  
Free Moment

The human foot provides numerous functions that let humans deal with various environments. Recently, study of the structure of the human foot and adjustment of an appropriate reaction force and vertical free moment during bipedal locomotion has gained attention. However, little is known about the mechanical (morphological) contribution of the foot structure to the reaction force and free moment. It is difficult to conduct a comparative experiment to investigate the contribution systematically by using conventional methods with human and cadaver foot experiments. This study focuses on the oblique transverse tarsal joint (TTJ) of the human foot, whose mechanical structure can generate appropriate free moments. We conduct comparative experiments with a rigid foot, a non-oblique joint foot (i.e. mimicking only the flexion/extension of the midfoot), and an oblique joint foot. Axial loading and walking experiments were conducted with these feet. The axial loading experiment demonstrated that the oblique foot generated free moment in the direction of internal rotation, as observed in the human foot. The walking experiment showed that the magnitude of the free moment generated with the oblique foot is significantly lower than that with the rigid foot during the stance phase. Using this constructive approach, the present study demonstrated that the oblique axis of the TTJ can mechanically generate free moments. This capacity might affect the transverse motion of bipedal walking.

scholarly journals Expression of Sigma-Class Glutathione-S-Transferase in Fetal and Pediatric Filum Terminale Samples: A Comparative Study

Medicina ◽  
2019 ◽  
Vol 55 (5) ◽  
pp. 133
Author(s):  
Cahit Kural ◽  
Serpil Oguztuzun ◽  
Gülçin Güler Şimşek ◽  
Servet Guresci ◽  
Pınar Kaygın ◽  
...  
Keyword(s):  
Tethered Cord ◽  
Filum Terminale ◽  
Glutathione S Transferase ◽  
Chi Square ◽  
Significant Difference ◽  
Chi Square Test ◽  
Normal Human ◽  
Group 2 ◽  
The Relationship ◽  
Group 1

Background and objectives: The pathophysiology of tethered cord syndrome (TCS) in children is not well elucidated. An inelastic filum terminale (FT) is the main factor underlying the stretching of the spinal cord in TCS. Our study aimed to investigate the expression of glutathione-S-transferase (GST) in children and fetal FT samples in order to understand the relationship between this enzyme expression and the development of TCS. Materials and Methods: FT samples were obtained from ten children with TCS (Group 1) and histological and immunohistochemical examinations were performed. For comparison, FT samples from fifteen normal human fetuses (Group 2) were also analyzed using the same techniques. Statistical comparison was made using a Chi-square test. Results: Positive GST-sigma expression was detected in eight (80%) of 10 samples in Group 1. The positive GST-sigma expression was less frequent in nine (60%) of 15 samples from Group 2. No statistically significant difference was detected between the two groups (p = 0.197). Conclusions: Decreased FT elasticity in TCS may be associated with increased GST expression in FT. More prospective studies are needed to clarify the mechanism of the GST–TCS relationship in children.

Voluntary activation of human quadriceps during and after isokinetic exercise

1991 ◽  
Vol 71 (6) ◽  
pp. 2122-2126 ◽  
Author(s):  
D. J. Newham ◽  
T. McCarthy ◽  
J. Turner
Keyword(s):  
Human Subjects ◽  
Knee Extension ◽  
Voluntary Activation ◽  
Isometric Contractions ◽  
Knee Angle ◽  
Lower Velocity ◽  
Isokinetic Contractions ◽  
Normal Human ◽  
Voluntary Contractions ◽  
The Relationship

The extent of voluntary activation in fresh and fatigued quadriceps muscles was investigated during isometric and isokinetic voluntary contractions at 20 and 150 degrees/s in 23 normal human subjects. The muscles were fatigued by a total of 4 min of maximal knee extension at an angular velocity of 85 degrees/s. Voluntary activation was determined by the superimposition of tetanic electrical stimulation at 100 Hz for 250 ms, initiated at a constant knee angle. The relationship between voluntary and stimulated force was similar to that found with the established twitch superimposition technique used on isometric contractions. In fresh muscle all the subjects showed full voluntary activation during isometric contractions. Some activation failure was seen in five subjects at 20 degrees/s [2.0 +/- 0.9 degrees (SE)] and in two subjects at 150 degrees/s (0.7 +/- 0.5). After fatigue all subjects showed some activation failure at 0 and 20 degrees/s (36.4 +/- 3.1 and 28.8 +/- 4.1 degrees, respectively), but only two showed any at 150 degrees/s (1.4 +/- 5.7). We conclude that brief high-intensity dynamic exercise can cause a considerable failure of voluntary activation. This failure was most marked during isometric and the lower-velocity isokinetic contractions. Thus a failure of voluntary activation may have greater functional significance than previous studies of isometric contractions have indicated.

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