Patterns and variations in morphology of glenoid cavity in mammals:Implications for locomotion efficiency
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Date
2019-02-01
Authors
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Journal ISSN
Volume Title
Publisher
Tanzania Veterinary Journal
Abstract
The aim of this study was to evaluate and compare the morphology and dimensions of
glenoid cavity and examine their relationship with body size and locomotion efficiency. The
study was performed on 356 glenoid cavities from 178 mammals, representatives of all major
taxa from rodents, sirenians, marsupials, pilosa, cetaceans, carnivores, ungulates, primates
and apes. Parameters measured included cranio-caudal and lateral-medial diameters and their
ratios; areas of articular surfaces; glenoid cavity index; angles-alpha, -beta and -gamma and
length of supraglenoid tubercle and coracoid process. Images were taken using computed
tomographic (CT) scanning technology (CT-Aquarium, Toshiba and micro CT- LaTheta,
Hotachi, Japan) and measurement values were acquired and processed using Avizo computer
software and CanvasTM 11 ACD systems. Statistical analysis was performed using Microsoft
Excel 2013. Results obtained showed that mammals exhibit various patterns in the
morphology of glenoid cavities that may be associated with adaptation of the glenohumeral
joint to robust mobility for locomotion. When the diameters of glenoid cavities were
compared between groups of mammals, significant difference was observed in diameters of
articular surfaces between rodents and ungulates (1.34±0.32); carnivores and primates
(1.39±0.16); primates and rodents and carnivores (1.3±0.12) and between ungulate and
carnivores, rodents and primates (1.19±0.18). The mean values of glenoid cavity index in
ungulates were found to be lower (0.15±0.13) than those of carnivores (0.22±0.71) and apes
(0.26±0.16), indicating that the depth of glenoid cavities of ungulates is shallow compared to
those of carnivores and apes. The inclination of the scapula relative to the trunk was found to
be tilted lateromedially in apes; mediolaterally in primates (monkeys); craniocaudally in
carnivores; vertically in ungulates and cranially in diggers. Significantly, the angles were
wider in apes but narrower in ungulates. The length of supraglenoid tubercle was long in
ungulates but short in carnivores while the coracoids process was short in ungulates but long
in primates and moderately in carnivores and other mammals. The morphological
characteristics of the glenoid cavities and the functional interpretation of the parameters in
mammals are discussed in detail.
Description
Keywords
Mammalian, Glenoid cavity, Morphology, CT analysis
Citation
C. Luziga and N. Wada (2019). Patterns and variations in morphology of glenoid cavity in mammals:Implications for locomotion efficiency. Tanzania Veterinary Journal, 34(2): 39-50. http://tvj.sua.ac.tz:9094/index.php/TVJ/article/view/96