scholarly journals The relationship between the glenoid track and the range of shoulder motion: A cadaver study

2018 ◽  
Vol 104 (6) ◽  
pp. 793-796 ◽  
Author(s):  
N. Yamamoto ◽  
J. Kawakami ◽  
H. Nagamoto ◽  
Y. Shiota ◽  
E. Itoi
Keyword(s):  
Cadaver Study ◽  
Glenoid Track ◽  
Shoulder Motion ◽  
The Relationship

In Vivo Glenoid Track Width Can Be Better Predicted With the Use of Shoulder Horizontal Extension Angle

2019 ◽  
Vol 47 (4) ◽  
pp. 922-927 ◽  
Author(s):  
Jun Kawakami ◽  
Nobuyuki Yamamoto ◽  
Toshimitsu Etoh ◽  
Taku Hatta ◽  
Mitsuyoshi Mineta ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Range Of Motion ◽  
Correlation Coefficient ◽  
External Rotation ◽  
Pearson Correlation ◽  
Sitting Position ◽  
Track Width ◽  
Glenoid Track ◽  
Shoulder Motion ◽  
The Relationship

Background: The glenoid track concept has been widely used to assess the risk of instability caused by a bipolar lesion. The mean glenoid track width is reported to be 83% of the glenoid width. However, this width seems to be affected by the range of motion of the shoulder. By clarifying the relationship between the range of shoulder motion and the glenoid track width, a more precise determination of the glenoid track width for each individual could be possible. Purpose: To determine the relationship between the glenoid track width and the range of motion of healthy volunteers. Study Design: Descriptive laboratory study. Methods: Magnetic resonance imaging was taken in 41 shoulders of 21 healthy volunteers (mean age, 32 years) with the arm in maximum horizontal extension, with the arm kept in 90° of abduction and 90° of external rotation. Three-dimensional surface bone models of the glenoid and the humerus were created with image analysis software. The distance from the anterior rim of the glenoid to the medial margin of the footprint of the rotator cuff tendon was defined as the glenoid track width. Active and passive ranges of shoulder motion were measured in the supine and sitting positions. The correlations between the glenoid track width and the ranges of shoulder motion were investigated with Pearson correlation coefficients. Intra- and interobserver reliabilities based on the intraclass correlation coefficient were also analyzed to assess the reliability of the glenoid track measurement. Results: The intra- and interobserver reliabilities for the glenoid track measurement were excellent (0.988 and 0.988, respectively). Among all the measurements, the glenoid track width and the active range of motion in horizontal extension in the sitting position showed the greatest correlation coefficient ( r = −0.623, P < .0001). A correlation between the glenoid track width and this angle was expressed as Y = −0.49 X + 90, where X is the horizontal extension angle (degrees) and Y is the glenoid track width (percentage of glenoid width). Conclusion: The present data demonstrate that the greater the horizontal extension angle in abduction and external rotation, the smaller the glenoid track width. An individualized glenoid track width can be obtained by measuring the active horizontal extension angle with the arm in abduction and external rotation in the sitting position. Clinical Relevance: An individualized glenoid track width enables selection of a more precise surgical option by the on-track/off-track concept.

scholarly journals Morphological Change in the Biceps Brachii Muscles during Shoulder Rotation: A Cadaver Study

2021 ◽  
Vol 11 (19) ◽  
pp. 9262
Author(s):  
Shuji Katsuki ◽  
Shogo Hayashi ◽  
Ryuta Tanaka ◽  
Daisuke Kiyoshima ◽  
Ning Qu ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Morphological Changes ◽  
External Rotation ◽  
Cadaver Study ◽  
Passive Movement ◽  
Mean Values ◽  
Significant Difference ◽  
Shoulder Motion ◽  
The Mean ◽  
Long Head

In the literature, the passive movement of the biceps brachii during shoulder motion is unclear. This study investigated the passive movement of the long head (LHBB) and short head (SHBB) of the biceps brachii during shoulder rotation. We included 18 shoulders from 15 cadavers. At three shoulder positions (internal rotation [IR]20°, 0°, external rotation [ER]20°), the three sides of the triangle consisting of the confluence of the SHBB and LHBB, coracoid processes, and lesser tubercles were measured. The confluence angle of the LHBB and SHBB (Angle A) was calculated using the cosine theorem. The mean values for Angle A and standardized three sides of the triangle were statistically compared among the three shoulder positions. Angle A values were 13.5° ± 7.6° at IR20°, 15.2° ± 5.8° at 0°, and 15.7° ± 4.3° at ER20° with no significant difference (p = 0.096). The lengths of all three sides and Angle A were the smallest at IR20° and highest at ER20°. All the three sides revealed significant differences among the three shoulder positions (p < 0.0001). These results imply that morphological changes of the biceps brachii occur during shoulder rotation. These morphological changes in biceps brachii may contribute to shoulder joint stabilization by adjusting the forces the act on the tendons of both heads.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Tinkering with cognitive gadgets: Cultural evolutionary psychology meets active inference

2019 ◽  
Vol 42 ◽  
Author(s):  
Paul Benjamin Badcock ◽  
Axel Constant ◽  
Maxwell James Désormeau Ramstead
Keyword(s):  
Evolutionary Psychology ◽  
Research Program ◽  
Active Inference ◽  
Innovative Research ◽  
Cognitive Faculties ◽  
Cultural Evolutionary ◽  
The Relationship

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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