scholarly journals Three-dimensional muscle architecture of the infant and adult trapezius: a cadaveric study

Author(s):  
Mikaela L. Stiver ◽  
Luke R. Bradshaw ◽  
Ethan M. Breinhorst ◽  
Anne M. R. Agur ◽  
S. Ali Mirjalili

Objectives: The elaborate morphometry of the human trapezius muscle facilitates its involvement in numerous active movements of the shoulder girdle and passive stabilization of the upper extremity. Despite its functional importance throughout the lifespan, little is known about the 3D architecture of trapezius at any post-natal timepoints. Accordingly, the aim of this preliminary cadaveric study was to digitize, quantify, model, and compare the 3D architecture of trapezius at two temporal extremes: infancy and adulthood. Methods: We examined trapezius in two female formalin-embalmed cadavers, aged 6 months and 72 years, respectively. We meticulously dissected each muscle, allowing us to digitize and model the comprehensive muscle architecture in situ at the fiber bundle level. We quantified standard architectural parameters to facilitate comparison between each functional partition of trapezius (i.e., descending, transverse, ascending) and proportionally between the infant and adult specimens. Results: We found markedly different patterns in fiber bundle length range, physiological cross-sectional area, and muscle volume within and between muscles. Notably, the proportional physiological cross-sectional area of the ascending and descending partitions was equal (1:1) in the infant, in contrast to 3:1 in the adult. The transverse partitions were proportionally similar, accounting for over half of the whole muscle physiological cross-sectional area in both specimens. Conclusion: This study provides preliminary insights into infant and adult trapezius architecture at an unparalleled level of detail and precision. The quantifiable architectural differences appear to coincide with functional development-a notion that warrants further investigation in larger samples and with longitudinal approaches.

2016 ◽  
Vol 52 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Ran S Sopher ◽  
Andrew A Amis ◽  
D Ceri Davies ◽  
Jonathan RT Jeffers

Data about a muscle’s fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.


2009 ◽  
Vol 95 (3) ◽  
pp. 203-212 ◽  
Author(s):  
Kajeandra Ravichandiran ◽  
Mayoorendra Ravichandiran ◽  
Michele L. Oliver ◽  
Karan S. Singh ◽  
Nancy H. McKee ◽  
...  

2003 ◽  
Vol 95 (6) ◽  
pp. 2229-2234 ◽  
Author(s):  
M. V. Narici ◽  
C. N. Maganaris ◽  
N. D. Reeves ◽  
P. Capodaglio

The effect of aging on human gastrocnemius medialis (GM) muscle architecture was evaluated by comparing morphometric measurements on 14 young (aged 27–42 yr) and on 16 older (aged 70–81 yr) physically active men, matched for height, body mass, and physical activity. GM muscle anatomic cross-sectional area (ACSA) and volume (Vol) were measured by computerized tomography, and GM fascicle length ( Lf) and pennation angle (θ) were assessed by ultrasonography. GM physiological cross-sectional area (PCSA) was calculated as the ratio of Vol/ Lf. In the elderly, ACSA and Vol were, respectively, 19.1% ( P < 0.005) and 25.4% ( P < 0.001) smaller than in the young adults. Also, Lf and θ were found to be smaller in the elderly group by 10.2% ( P < 0.01) and 13.2% ( P < 0.01), respectively. When the data for the young and elderly adults were pooled together, θ significantly correlated with ACSA ( P < 0.05). Because of the reduced Vol and Lf in the elderly group, the resulting PCSA was found to be 15.2% ( P < 0.05) smaller. In conclusion, this study demonstrates that aging significantly affects human skeletal muscle architecture. These structural alterations are expected to have implications for muscle function in old age.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7764
Author(s):  
Ho-Jae Lee ◽  
Eun-A Seo ◽  
Won-Woo Kim ◽  
Jun-Mo Yang ◽  
Jae-Heum Moon

In this study, we experimentally analyzed the deformation shape of stacked layers developed using three-dimensional (3D) printing technology. The nozzle traveling speed was changed to 80, 90, 100, and 110 mm/s when printing the layers to analyze its effect on layer deformation. Furthermore, the cross-sectional area and the number of layers were analyzed by printing five layers with overall dimensions of 1000 (w) × 2200 (l) × 50 (h) mm (each layer was 10 mm high) using Vernier calipers. Moreover, we analyzed the interface and cross-sectional area of layers that are difficult to confirm visually using X-ray computed tomography (X-ray CT) analysis. As a result of measuring the deformation at the center of the layer, it was confirmed that the deformation was greater for lower nozzle traveling speeds. Consequently, the X-ray CT analysis verified that the layer had the same cross-sectional area irrespective of the layer printing order at the same nozzle travel speed, even if the layer was deformed.


2001 ◽  
Vol 27 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Daniel F Leotta ◽  
Jean F Primozich ◽  
Kirk W Beach ◽  
Robert O Bergelin ◽  
D.Eugene Strandness

2016 ◽  
Vol 87 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Seerone Anandarajah ◽  
Raahib Dudhia ◽  
Andrew Sandham ◽  
Liselotte Sonnesen

ABSTRACT Objective: To analyze which parameters, gathered from standard orthodontic diagnostic material, were most relevant for identifying small pharyngeal airway dimensions in preorthodontic children. Materials and Methods: The sample was composed of 105 cone beam computed tomography scans of healthy preorthodontic children (44 boys, 61 girls; mean age, 10.7 ± 2.4 years). Airway volume and minimal cross-sectional area were three-dimensionally assessed. Cephalometric features and skeletal maturity were assessed on generated two-dimensional cephalograms. Associations were analyzed and adjusted for age, gender, and skeletal maturity by multiple regression analyses. Results: Airway volume and minimal cross-sectional area were significantly smaller in prepubertal children (P &lt; .001, P &lt; .05, respectively) and positively associated with age (P &lt; .001, P &lt; .01, respectively). After adjustment of age, skeletal maturity and gender significant associations were found between pharyngeal airway dimensions and craniofacial morphology. Airway volume was positively associated with maxillary and mandibular width (P &lt; .01; P &lt; .001, respectively) and anterior face height (P &lt; .05; P &lt; .05, respectively). Minimal cross-sectional area was positively associated with maxillary and mandibular width (P &lt; .01; P &lt; .001, respectively) and negatively associated with sagittal jaw relationship (AnPg, P &lt; .05). Mandibular width and age were the most relevant factors for airway volume (r2 = 0.36). Mandibular width and sagittal jaw relationship were the most relevant factors for minimal cross-sectional area (r2 = 0.16). Conclusion: Pharyngeal airway dimensions were significantly associated with age, skeletal maturity, and craniofacial morphology in all three planes. Children with a reduced mandibular width and increased sagittal jaw relationship are particularly at risk of having small pharyngeal airway dimensions.


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