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PubMed1991

Cat Distal Forelimb Joints and Locomotion: An X-ray Study.

The complex construction of the joint apparatus of the cat distal forelimb, which allows the paw three degrees of freedom, poses special requirements on the neural signals controlling the paw position. To understand the electromyography (emg) signals of the distal forelimb muscles during locomotion, it is necessary to know the kinematics of the forelimb joints in detail. As no such information is available, we used the pulsed X-ray technique in trained cats during treadmill locomotion to analyse the angular excursions of the wrist, the metacarpophalangeal (MCP) and the proximal interphalangeal (PIP) joints. X-ray illuminations were done in either the parasagittal or the frontal plane. At the beginning of the stance phase the wrist (WR) and the MCP joints extended slowly, and the PIP joints flexed. Whereas the WR and the PIP joints maintained a constant angular position of approximately 200 degrees and 60 degrees, respectively, throughout the stance phase, extension continued in the MCP joints from 240 degrees at touch-down to 300 degrees at the end of the stance phase. Slightly before lift-off (100 ms) the WR and the MCP joints flexed rapidly. This flexion changed approximately 150 ms after lift-off into a slow extension. The PIP joints extended rapidly at the beginning and at the end of the swing phase, during the interposed period of the swing phase they displayed a slow flexion. Rotatory movements of the forelimb in the radioulnar joints were present during the swing and stance phases. During the swing phase the limb first supinated (starting 100 ms after lift-off); pronation occurred immediately before ground contact. During the stance phase the supination angle was kept constant until 100 ms before lift-off, when a short pronation was found. The paw was kept in an ulnar deviated position throughout the complete step cycle. Ulnar deviation decreased at the end of the swing and stance phases. The results of this study increase our understanding of how the body weight is transmitted on to the ground. They suggest four main functions for the skeletomotor apparatus and the underlying neural commands to secure the forward movement of the animal during the stance phase: (i) preparation and stabilization of a force-transmitting platform; (ii) stabilization of the wrist and the carpal/metacarpal joints; (iii) stabilization of the supination angle; (iv) antigravity control of the extension in the MCP.

Journal Article↗
PubMed1985

Carotid sinus and blood pressure control during hindlimb and forelimb contractions.

Arterial blood pressure (ABP) regulation during exercise involves in part medullary interaction of afferent information from contracting skeletal muscles and the major baroreceptors. This study examined in chloralose-anesthetized dogs the role of the carotid sinus baroreceptors in modulating reflex changes in ABP, nonexercising hindlimb skeletal muscle vascular resistance, and heart rate (HR) evoked by two separately contracting (4, 16, and 48 Hz) groups of skeletal muscle, the right hindlimb and forelimb. When arterial and cardiopulmonary baroreceptor afferent information was interrupted, hindlimb contractions evoked a greater augmentation of ABP (16 and 48 Hz) and no further increase in nonexercising hindlimb perfusion pressure (HLPP). Forelimb contractions, which in the presence of baroreceptors had not affected ABP (4 and 16 Hz), now reduced it profoundly. Nonexercising HLPP, which increased independently of contraction frequency, now was decreased by 4 Hz, not affected by 16 Hz, and increased by 48 Hz. The increase in HR was abolished. Increasing carotid sinus pressure to 220 mmHg in vagotomized dogs abolished the reflex changes evoked by hindlimb skeletal muscle contractions. However, forelimb contractions continued to decrease ABP. Nonexercising HLPP and HR did not change from the precontraction values. These data indicate that the carotid sinus baroreceptor could buffer completely those changes in the selected cardiovascular variables evoked by hindlimb but not forelimb skeletal muscle contractions. Thus the role of the carotid sinus baroreceptors in controlling ABP during exercise depends on the group of skeletal muscle initiating the somatic afferent signal and its influence on the contraction-induced distribution of the efferent signals.

Animals↗
PubMed1999

The homeobox gene Msx1 is expressed in a subset of somites, and in muscle progenitor cells migrating into the forelimb.

In myoblast cell cultures, the Msx1 protein is able to repress myogenesis and maintain cells in an undifferentiated and proliferative state. However, there has been no evidence that Msx1 is expressed in muscle or its precursors in vivo. Using mice with the nlacZ gene integrated into the Msx1 locus, we show that the reporter gene is expressed in the lateral dermomyotome of brachial and thoracic somites. Cells from this region will subsequently contribute to forelimb and intercostal muscles. Using Pax3 gene transcripts as a marker of limb muscle progenitor cells as they migrate from the somites, we have defined precisely the somitic origin and timing of cell migration from somites to limb buds in the mouse. Differences in the timing of migration between chick and mouse are discussed. Somites that label for Msx1(nlacZ )transgene expression in the forelimb region partially overlap with those that contribute Pax3-expressing cells to the forelimb. In order to see whether Msx1 is expressed in this migrating population, we have grafted somites from the forelimb level of Msx1(nlacZ )mouse embryos into a chick host embryo. We show that most cells migrating into the wing field express the Msx1(nlacZ )transgene, together with Pax3. In these experiments, Msx1 expression in the somite depends on the axial position of the graft. Wing mesenchyme is capable of inducing Msx1 transcription in somites that normally would not express the gene; chick hindlimb mesenchyme, while permissive for this expression, does not induce it. In the mouse limb bud, the Msx1(nlacZ )transgene is downregulated prior to the activation of the Myf5 gene, an early marker of myogenic differentiation. These observations are consistent with the proposal that Msx1 is involved in the repression of muscle differentiation in the lateral half of the somite and in limb muscle progenitor cells during their migration.

Animals↗
PubMed1986

Premotor cortex neurons in macaques: activity before distal and proximal forelimb movements.

Single unit activity was examined in the premotor cortex of three awake, behaving macaque monkeys. Premotor cortex (PM) neurons were found to be active in association with a movement involving specifically the distal forelimb. Other PM neurons were active in relation to more proximal forelimb movements. The spatial distribution of neurons related to distal movements differed from that of neurons related to proximal forelimb movements, the former being focused at a postarcuate region near the genu of the arcuate sulcus and the latter being shifted more posteromedially. The distal movement was triggered by one of the three sensory signals: visual, auditory, and vibrotactile. Of 190 PM neurons related to the distal forelimb movements, 123 (65%) showed similar premovement activity changes irrespective of the modality of the triggering signal. However, a number of neurons (35%) responded preferentially to one or two of the three signals. The modality-specific activity before movements distinguishes PM from the caudally adjacent primary motor cortex.

Animals↗
PubMed1993

Visually guided reaching with the forelimb contralateral to a "blind" hemisphere: a metabolic mapping study in monkeys.

The 2-14C-deoxyglucose method was used to map local cerebral metabolic activity in monkeys performing a unimanual task requiring visually guided arm reaching and key pressing. The study was carried out with monkeys that either had intact brains or had one hemisphere deprived of visual input by unilateral optic tract section combined in some cases with forebrain commissurotomy. The metabolic mapping revealed activation of sensorimotor cortex only in the hemisphere contralateral to the moving forelimb, irrespective of whether this hemisphere was intact or visually deafferented. These results suggest that visually guided reaching with the forelimb contralateral to the "blind" hemisphere is subserved by that hemisphere's sensorimotor cortex and not by the cortex of the ipsilateral, "seeing" hemisphere. Other areas that were more active metabolically in the "blind" than in the "seeing" hemisphere included the supplementary motor, the secondary somatosensory, and certain posterior parietal cortical areas, intraparietal lateral 5 (lateral 5-ip), 7a, and intraparietal 7 (7-ip). It is suggested that the "blind" hemisphere utilizes at least two distinct pieces of information to guide forelimb movements to visual targets: (1) information about the location of the visual target derived from head and eye movements made to this target and mediated via the inferior parietal cortical areas 7a and 7-ip, and (2) information about the instantaneous upper extremity position derived from forelimb proprioceptive mechanisms and mediated via the somatosensory cortex and thereafter via the superior parietal cortical area, lateral 5-ip.

Animals↗
PubMed2000

Cervical motoneuron topography reflects the proximodistal organization of muscles and movements of the rat forelimb: a retrograde carbocyanine dye analysis.

Behavioral evidence reveals that the laboratory rat and other rodent species display skilled paw and digit use in handling food during eating and skilled limb use in reaching for food in formal laboratory skilled reaching tests that is comparable to that described in carnivores and primates. Because less is known about the central control of skilled movements in rodents than in carnivores or primates, the purpose of the current study was to examine the relation between the rat's spinal motoneurons and the individual forelimb muscles that they innervate. In two experiments, 14 forelimb muscles (in the shoulder and the upper and lower arm segments) were injected with carbocyanine dye tracers. The topography of spinal motoneurons was reconstructed by using fluorescence microscopy. Motor neurons were found to be organized in columns throughout the length of the cervical and upper thoracic area, with 1) extensor motoneurons located more laterally than flexor motoneurons, 2) rostral motoneurons innervating more proximal muscles than caudal motoneurons, and 3) more dorsally located motoneurons innervating more distal muscles. These results reveal that the topography of rodent cervical spinal cord motoneurons is very similar to that of carnivores and of primates, which also are characterized by well-developed, skilled movements. In addition, the proximal-distal organization of motoneuron columns parallels the proximal-to-distal pattern of forelimb movement used by the rat when reaching. The data from this study enable the development of predictions about the specific movements that would be compromised by experimental transections or other injuries at different levels of the spinal cord in rat models of spinal injury.

Animals↗
PubMed1997

Evolution of forelimb movement patterns for prey manipulation in anurans.

Unlike other amphibians, frogs often use their forelimbs to capture and transport prey. In the present study, high-speed videography was used to observe forelimb use during feeding in a diverse group of anurans in order to determine the evolution of forelimb movement patterns among anuran taxa. Data were gathered from 488 individuals representing 104 species, 55 genera, and 16 families. Five distinct behavior patterns were identified: scooping entails using the back of the hand to push prey into the mouth; wiping involves the use of the palm of the hand to push prey, protruding laterally from the mouth, toward the midline; during prey stretching, one end of the prey is held in a stationary position by the hands while the other end is pulled upward by the jaws; in grasping, the palms face the midline or the substrate as the fingers are wrapped around the prey; grasping with wrist rotation is similar to grasping, but the wrists rotate inward as the hands grasp the prey so that the palms face the mouth. The distribution of these behavior patterns was mapped onto the most recent phylogenetic hypothesis for anurans. Maximum parsimony analyses suggest that scooping and wiping are primitive and have been retained by many frog lineages. Wiping was not observed in the pipids, which are the only anurans that lack tongues and use hydraulic transport. Prey stretching appears to have evolved several times in unrelated taxa. Grasping and grasping with wrist rotation appear to have evolved only in arboreal groups, suggesting that the ability to climb is a preadaptation for the ability to grasp prey. Several species were observed using grasping motions in place of the tongue to capture prey.

Animals↗
PubMed1998

Effects of testosterone administration and castration on the forelimb musculature of male leopard frogs, Rana pipiens.

In Rana pipiens, forelimb muscles that are used by males to clasp females during amplexus are sexually dimorphic in mass, protein content, and fiber composition. This experiment examined the effects of castration and exogenous testosterone on wet mass, dry mass, and protein content of the 22 major forelimb muscles of male leopard frogs to determine whether established patterns of sexual dimorphism of the muscles are reflected in differential androgen sensitivity. Muscles ranged from highly and moderately responsive to testosterone treatment (e.g., flexors of the elbow and of the carpus; adductors of the shoulder and of the first digit) to nonresponsive to testosterone (antagonists to these muscles). The mean dry mass of the testosterone-responsive muscles ranged broadly from 28-164% over control values. Castration had little or no effect on the response to testosterone, nor did it affect muscle mass in frogs not treated with hormone, as compared to sham-operated animals. Experimental treatment did not alter water content or protein concentration of muscles. The degree of testosterone sensitivity exhibited among the muscles of males closely correlated with their degree of sexual dimorphism. We postulate that androgens influence the functional attributes of male forelimb muscles through both organizational and activational effects.

Analysis of Variance↗
PubMed2005

A teratoproteomics analysis: heat shock protein 70 is upregulated in mouse forelimb bud by methoxyacetic acid treatment.

BACKGROUND: Methoxyacetic acid (MAA) causes fetal limb abnormalities when the substance is administrated on gestation day (GD) 11 in mice. Limb abnormalities are caused mainly by extensive cell death in the mesoderm of the limb plate. This investigation focused on identifying a protein that is linked with mouse limb teratogenicity. METHODS: A single dose of MAA at 10 mmol/kg body weight was administered by gavage on GD 11; controls were administered vehicle only. Dams were killed by cervical dislocation 4 hr after treatment and forelimb buds were isolated from both the control and treated embryos. Proteins in forelimb buds GD 11 + 4 hr were precipitated out using 40-60% ammonium sulfate and were then analyzed by 2D SDS-PAGE. Excised protein spots were identified by mass spectrometry and amino acid internal sequence analysis. Identified protein was further confirmed by Western blotting. RESULTS: Two-dimensional gel analysis indicated that 1 protein spot of 81.7 kDa/pI 7.3 was overexpressed, and the protein matched heat shock protein 70 (HSP70; accession no. P08109, SwissProt). CONCLUSIONS: The results suggest that MAA, when administered to pregnant mice, upregulates HSP70 in the forelimb buds.

Abnormalities, Drug-Induced↗
PubMed2004

Dose-response for retinoic acid-induced forelimb malformations and cleft palate: a comparison of computerized image analysis and visual inspection.

BACKGROUND: The objectives of this study were to (1) compare two techniques (computerized image analysis and visual morphological evaluation) for the assessment of fetal forelimb malformations and (2) increase the robustness of the dose-response curve for forelimb and cleft palate malformations resulting from all-trans retinoic acid (RA) exposure in GD 11 mice. METHODS: Pregnant CD-1 mice were administered a single oral dose of all-trans RA (0, 2.5, 10, 30, 60, or 100 mg/kg) on GD 11. GD 18 fetuses were examined for malformations using visual morphological scoring and computerized image analysis. RESULTS: Dose-dependent changes occurred in the size and shape of the humerus, radius, and ulna based on both assessment methodologies. The most sensitive indicators for the lowest effect level (10 mg/kg) on forelimbs were roundness, a shape measurement determined by image analysis, and visual morphological scoring. For all other bone measurements (proximal and distal width, area, length, and perimeter), the lowest effect level was 30 mg/kg. The maximum effect for limb defects and total malformed fetuses was seen at 60 mg/kg and higher. Incidence of cleft palate increased over the entire range of administered doses reaching a maximum of 74% (100 mg/kg). CONCLUSIONS: Overall, results indicate that computerized image analysis was no more sensitive in detecting changes in the humerus, radius, and ulna than gross visual examination. Dose-response modeling of developmental endpoints yielded comparable benchmark dose levels for long bones and cleft palate that ranged from 0.24 to 7.6 mg/kg all-trans RA. Birth Defects Res B 71:289-295, 2004.

Abnormalities, Drug-Induced↗
PubMed2003

Comparison of reorganization of the somatosensory system in rats that sustained forelimb removal as neonates and as adults.

Studies of sensory pathways in several species indicate that the extent and form of reorganization resulting from deafferentation early in life vs. adulthood are not the same. The reasons for such differences are not well understood. To gain further insight into age-dependent mechanisms of reorganization, this study compared the consequences of neonatal vs. adult forelimb amputation in rats at multiple levels of the sensory pathway, including primary somatosensory cortex, brainstem, and dorsal root ganglia. At the cortical level, the average area of the functional forelimb-stump representation from rats amputated as adults was significantly smaller (P < 0.05) than that of neonatally amputated rats (4.3 +/- 1.3 mm(2) vs. 6.6 +/- 1.5 mm(2), respectively). At the brainstem level, neonatally amputated rat cuneate neurons possessed the following responsivities: 20% stump responsive, 40% responsive to both stump and hindlimb, 30% responsive to another body region, and 10% unresponsive. In contrast, cuneate neurons of adult amputated rats were 70% stump responsive, 2% responsive to both stump and hindlimb, and 30% unresponsive. A significantly (P < 0.001) greater percentage of the C(6)-C(8) dorsal root ganglia neurons of adult amputated rats were unresponsive to peripheral stimulation vs. neurons from neonatally amputated rats (48% vs. 16%, respectively). These results indicate that the reorganization that occurs in response to forelimb amputation at birth vs. adulthood is distinctly different at each of these levels of the dorsal column-medial lemniscal pathway. Possible mechanisms to account for these differences are considered.

Action Potentials↗
PubMed1986

Location of motoneurones projecting to the cat distal forelimb. I. Deep radial motornuclei.

The position of the motornuclei projecting through the dorsal interosseus (DR) nerve to the distal forelimb muscles has been investigated in the cat. Horseradish peroxidase (HRP) and fluorescent (Fl) compounds have been used as retrograde tracers. They were either injected into forelimb muscles or applied to the proximal end of transected forelimb nerves. Limb muscles that were not investigated have been carefully denervated. HRP was used to trace the position and the architecture of the individual motornuclei. The topographical relations between the nuclei were established with application of up to three F compounds in the same animal. The position of the labeled motornuclei was reconstructed with a computer-assisted approach which is described in the appendix. The DR representation area extends from the caudal C5 to the caudal Th1 segments. In C6 it forms a dorsoventrally oriented narrow region at the lateral border of the ventral horn; in C7 and rostral C8 it forms a broad column in the dorsolateral corner of the ventral horn. In caudal C8 and Th1 this column is shifted into a ventral direction. The motoneurones projecting to the individual DR muscles are not randomly distributed in this area, but arranged in long, slender columns. These motornuclei occupy specific positions with only minimal interindividual variations. Three nuclei (brachioradialis, extensor carpi radialis, and supinator) are located in the C6 and C7 segments. They compose about one-third of the DR cell population. The nuclei to the other radial muscles are all located in C8 and Th1. Thus most of the DR motoneurones are located in these two segments. These results, together with those from the companion paper on the location of the median and ulnar motornuclei, provide important anatomical knowledge for the investigation of the cat brachial enlargement.

Animals↗
PubMed1986

Location of motoneurones projecting to the cat distal forelimb. II. Median and ulnar motornuclei.

The position of the motornuclei projecting through the median (Mn) and ulnar (Ul) nerves to the cat distal forelimb has been investigated. Horseradish peroxidase (HRP) and fluorescent (Fl) compounds have been used as retrograde tracers. They were either injected into forelimb muscles or applied to the proximal end of transected forelimb nerves. Limb muscles that were not investigated were carefully denervated. The position and the architecture of the individual motornuclei were traced with HRP. The topographical relations between the nuclei were established with application of up to three different Fl compounds in the same animal. The Mn motoneurones had a bimodal distribution in the brachial spinal cord. The motoneurones to the pronator teres and flexor carpi radialis muscles were located in C7 and the other Mn motoneurones were located in C8 and Th1. In C7 the Mn motoneurones occupied a single representation area, which is located some distance medially of the lateral funiculus. In C8 and Th1 two Mn representation areas were found: A dorsal one that contacts the lateral funiculus and is located at the level of the central canal; a ventral one that is located ventrally in the ventral horn. The dorsal area is occupied by the motornuclei projecting to the intrinsic hand muscles and the ventral one by the nuclei projecting to the limb. The Ul motoneurones extend with an unimodal distribution from the caudal C7 to the caudal Th1 segments. They occupy a single, broad representation area. The dorsal part, which contacts the lateral funiculus, is located at the level of the central canal and harbours the nuclei to the intrinsic hand muscles. The other Ul nuclei are located ventromedially deep in the ventral horn. These results, together with those from the companion paper on the location of the deep radial motornuclei, provide important anatomical information for the investigation of the cat brachial enlargement.

Animals↗
PubMed2005

Transcriptome analysis of the murine forelimb and hindlimb autopod.

To gain insight into the coordination of gene expression profiles during forelimb and hindlimb differentiation, a transcriptome analysis of mouse embryonic autopod tissues was performed using Affymetrix Murine Gene Chips (MOE-430). Forty-four transcripts with expression differences higher than 2-fold (T test, P < or = 0.05) were detected between forelimb and hindlimb tissues including 38 new transcripts such as Rdh10, Frzb, Tbx18, and Hip that exhibit differential limb expression. A comparison of gene expression profiles in the forelimb, hindlimb, and brain revealed 24 limb-signature genes whose expression was significantly enriched in limb autopod versus brain tissue (fold change >2, P < or = 0.05). Interestingly, the genes exhibiting enrichment in the developing autopod also segregated into significant fore- and hindlimb-specific clusters (P < or = 0.05) suggesting that by E 12.5, unique gene combinations are being used during the differentiation of each autopod type.

Animals↗
PubMed1982

Pattern regulation during regeneration of embryonically produced symmetrical forelimbs in the axolotl, ambystoma mexicanum.

Embryonic axolotls (Stages 32-34) underwent surgery during which a graft of flank tissue was transferred from a donor animal to the anterior margin of the forelimb field in a host animal. Double-posterior forelimbs containing from one to eight digits developed. These limbs were amputated at a level proximal to the elbow to assess their regenerative ability. The majority (62%) of these limbs failed to regenerate externally visible structures. Symmetrical limbs bearing five digits or more than five digits regenerated with greatest frequency (54%). Symmetrical forelimbs bearing four digits or fewer that four digits regenerated less frequently (31%). All regenerates displayed double-posterior symmetry and usually contained fewer digits than were present in the original limb. The significance of these findings is discussed in the context of the current model for pattern regulation in epimorphic fields.

Ambystoma↗
PubMed1985

Pattern-deficient forelimb regeneration in adult bullfrogs.

This study was designed to test the ability of adult bullfrogs (Rana catesbeiana) to regenerate forelimbs, both with and without various experimental treatments. Distal humerus-level forelimb amputations provided with additional deviated (sciatic) nerve and/or repeated soft-tissue injury exhibited considerable outgrowth. However, control sham-operated forelimbs also produced regenerates with comparable frequency, size, and morphological complexity. The lengths of the regenerates ranged from 0.4 to 2.6 cm, representing an outgrowth of 10-65% of the portion removed by the distal humerus amputation plane; some regenerates exhibited an external morphology indicative of digitlike structures. Some outgrowths were flexible but only one was capable of independent movement. Victoria Blue staining of whole regenerates revealed a variety of internal cartilage elements. Staining showed a single solid mass of cartilage in some regenerates while others had several individual and variably shaped cartilages projecting distally. Histological analysis also revealed the presence of connective tissue, striated muscle, and abundant nerve fibers in addition to the individual cartilage elements. We have tentatively termed these responses pattern-deficient regeneration.

Animals↗
PubMed2003

Architectural properties of distal forelimb muscles in horses, Equus caballus.

Articular injuries in athletic horses are associated with large forces from ground impact and from muscular contraction. To accurately and noninvasively predict muscle and joint contact forces, a detailed model of musculoskeletal geometry and muscle architecture is required. Moreover, muscle architectural data can increase our understanding of the relationship between muscle structure and function in the equine distal forelimb. Muscle architectural data were collected from seven limbs obtained from five thoroughbred and thoroughbred-cross horses. Muscle belly rest length, tendon rest length, muscle volume, muscle fiber length, and pennation angle were measured for nine distal forelimb muscles. Physiological cross-sectional area (PCSA) was determined from muscle volume and muscle fiber length. The superficial and deep digital flexor muscles displayed markedly different muscle volumes (227 and 656 cm3, respectively), but their PCSAs were very similar due to a significant difference in muscle fiber length (i.e., the superficial digital flexor muscle had very short fibers, while those of the deep digital flexor muscle were relatively long). The ulnaris lateralis and flexor carpi ulnaris muscles had short fibers (17.4 and 18.3 mm, respectively). These actuators were strong (peak isometric force, Fmax=5,814 and 4,017 N, respectively) and stiff (tendon rest length to muscle fiber length, LT:LMF=5.3 and 2.1, respectively), and are probably well adapted to stabilizing the carpus during the stance phase of gait. In contrast, the flexor carpi radialis muscle displayed long fibers (89.7 mm), low peak isometric force (Fmax=555 N), and high stiffness (LT:LMF=1.6). Due to its long fibers and low Fmax, flexor carpi radialis appears to be better adapted to flexion and extension of the limb during the swing phase of gait than to stabilization of the carpus during stance. Including muscle architectural parameters in a musculoskeletal model of the equine distal forelimb may lead to more realistic estimates not only of the magnitudes of muscle forces, but also of the distribution of forces among the muscles crossing any given joint.

Animals↗
PubMed2005

Morphometric and anatomic study of the forelimb of the dog.

The object of this study was to obtain the anatomic and morphometric data required for biomechanical analyses of the forelimb in dogs. Following the euthanasia of four healthy, adult, crossbred dogs, 44 muscles of the right forelimb were identified and meticulously removed. Morphometric data for all muscles were collected and physiologic cross-sectional areas (PCSA) and architectural indices (AI) were calculated. The coordinates of the origin and insertion of each muscle were determined using orthogonal, right-handed coordinate systems embedded in the scapula, humerus, and radius-ulna. The PCSA and AI were calculated for all the muscles and coordinates for the origins and insertions of these muscles were determined. Results provide the morphometric and anatomic data necessary for three-dimensional biomechanical studies of the forelimb in dogs.

Animals↗