Growth Dynamics of the Triceps Brachii Muscle in the Human Fetus

Abstract

Background. The triceps brachii muscle, the strongest extensor of the elbow joint, is characterized by the three heads: long, lateral and medial. Objectives. In the present study we aimed to examine the linear parameters (length, width) of the fetal triceps brachii muscle and to provide their growth dynamics. Material and Methods. Using anatomical dissection, digital image analysis (Multiscan v.14.02), and statistics (Student's t-test, regression analysis) we measured in mm the length and width of the triceps brachii in 30 fetuses of both sexes (12♂,18♀) aged 12-29 weeks. Results. Neither sex nor laterality differences were found. all the parameters studied increased proportionately with age. The linear functions were computed as follows: y = 6.797 + 2.079 x age (r = 0.886) for length of the long head's belly, y = -0.041 + 0.215 × age (r = 0.786) for width of the long head's belly, y = 1.889 + 0.174 × age (r = 0.796) for length of the long head's proximal tendon, y = 0.158 + 0.052 × age (r = 0.864) for width of the long head's proximal tendon, y = 5.270 + 1.809 × age (r = 0.855) for length of the lateral head's belly, y = 0.348 + 0.284 × × age (r = 0.829) for width of the lateral head's belly, y = 0.942 + 1.837 × age (r = 0.839) for length of the medial head's belly, y = 0.314 + 0.234 × age (r = 0.852) for width of the medial head's belly, y = -3.191 + 0.984 × age (r = 0.929) for lenght of the common tendon, and y = -0.478 + 0.133 × age (r = 0.933) for width of the common tendon. Conclusions. Neither male-female nor right-left differences are observed in morphometric parameters of the triceps brachii muscle. The long head's belly is the thinnest, while the lateral head's belly is the widest one. The long head is the longest and the medial head is the shortest one. The developmental dynamics of the triceps brachii muscle follow proportionately (Adv Clin Exp Med 2014, 23, 2, 177-184).

Morphometric properties of the tensor fascia lata muscle in human foetuses

“…In accordance with the previous study results on morphometric properties of different muscle groups [2,4,13,14,17], this study revealed a rational increase in numerical values of TFL surface area, width and lengths from 18 th to 30 th week and showed no statistically significant difference between sides and sexes.…”

“…Although literature reported a number of differences in many muscle growth dynamics between fetuses [2,4,13,14,17,25], no quantitative studies on TFL were…”

Mathematical modelling of the growth of human fetus anatomical structures

“…Neither sexual dimorphism nor asymmetry was very characteristic. Other observations based on less material comprising a smaller age span (Badura et al 2011a, b; Grzonkowska et al 2014; Szpinda et al 2011, 2013) revealed similar results.…”

“…1) present parameters of analysed monoequation, biparametric ( b 0 and b 1 ) mathematical models for CRL of the trunk ( verte - tuberale ). Approximation was made on the basis of CRLs included in Scammon’s and Calkins’ tables (Bożiłow and Sawicki 1980; Grzonkowska et al 2014). Extrapolation of a linear model from the first weeks of life results in negative values (Fig.…”

Quantitative Anatomy of the Trapezius Muscle in the Human Fetus

“…They found no sex differences, which is in line with our current study. Furthermore, numerous morphometric studies on skeletal muscles in the human fetus, including triceps brachii [23], biceps brachii [24], deltoid [25], semitendinosus [26], semimembranosus [27], and biceps femoris [28] indubitably divulged no significant male-female differences. Not even once did we notice any laterality differences in the material under examination.…”