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Quadrupedal Mechanics - Anatomy & Physiology (view source)
Revision as of 06:23, 28 November 2013
, 06:23, 28 November 2013→Patterns of limb joint movement
==='''Patterns of limb joint movement'''===
==='''Patterns of limb joint movement'''===
The possible movements in the corresponding joints between the forelimb and hindlimb have some similarities between the different limb segments:
The possible movements in the corresponding joints between the forelimb and hindlimb have some similarities between the different limb segments:
:::::'''Forelimb''' '''Hindlimb''' '''Axes of movement'''
:::::Shoulder Hip Flexion-extension; Adduction-abduction; Rotation
:::::Elbow Stifle Flexion-extension; Rotation
:::::Carpus Tarsus Flexion-extension
:::::Metacarpo- & metatarsophalangeal Flexion-extension
:::::Interphalangeal Flexion-extension
The axes of movement thus become more restricted distally. A limb can be regarded as an extensible rod, rather freely moveable about the shoulder and hip joints, and extensible because flexion and extension are possible in all joints, in an alternating pattern distally as far as the metacarpophalangeal joints (Fig. 8.1). Proximally, the more complex movements are matched by the complexity of the muscles surrounding these joints.
The axes of movement thus become more restricted distally. A limb can be regarded as an extensible rod, rather freely moveable about the shoulder and hip joints, and extensible because flexion and extension are possible in all joints, in an alternating pattern distally as far as the metacarpophalangeal joints (Fig. 8.1). Proximally, the more complex movements are matched by the complexity of the muscles surrounding these joints.
[[File:QMFig 8.1.png|thumb|'''Fig 8.1 Flexion and extension of the limbs of the horse during the gallop''']]
:::::'''Fig 8.1 Flexion and extension of the limbs of the horse during the gallop'''
:::::Note the extreme flexion of joints distal to the stifle and elbow during protraction, the interdependence of stifle and hock movement, and that the flexion position differs markedly between forelimb and hindlimb.
:::::Note the extreme flexion of joints distal to the stifle and elbow during protraction, the interdependence of stifle and hock movement, and that the flexion position differs markedly between forelimb and hindlimb.
==='''Limbs as struts'''===
==='''Limbs as struts'''===