Features of organometric parameters of the palm in the perinatal period of ontogenesis

Selective single data on the organometric parameters of the palm in the perinatal period of ontogenesis determines the relevance of the study. The purpose of the study is to establish the organometric parameters of the palm during the fetal and early neonatal periods of human ontogenesis. The study of the palm was performed on 51 preparations of fetal corpses (from 4 to 10 months) and 10 newborns using adequate anatomical methods: macropreparation, radiography, topographic and anatomical sections, morphometry, statistical analysis. It was found that the right hand in the perinatal period of ontogenesis is characterized by its elbow shape (54 %), for the left hand radial (71 %). The parameters of the length of the right palm are greater than the parameters of the length of the left palm in the second trimester of fetal development and in the neonatal period; in the third trimester of fetal development the length of the left palm is greater than the length of the right. The parameters of the width of the right palm exceed these parameters of the left palm during the entire perinatal period of ontogenesis. During the perinatal period of ontogenesis the organometric parameters of the palm are characterized by two periods of accelerated development and a period of relatively slow development. For the length and width of the right and left palms, periods of accelerated development from the 4th to the 5th month of fetal development and from the 7th month to the neonatal period; from the 5th to the 7th month of fetal development a period of relatively slow development. Models for predicting the normative values of organometric parameters of the palm during the perinatal period of ontogenesis are: palm length = β 0 + 0.042 x crown-heel length of the fetus, where β 0 : 3.587, if the age period = 4 months; 5.562 = 5 months; 4.071 = 6 months; 4.840 = 7 months; 6.881 = 8 months; 5.624 = 9 months; 5.448 = 10 months; 5.765 = newborns; palm width = β 0 + 0.038 x crown-heel length of the fetus, where β 0 : 2.887, if age period = 4 months; 4.341 = 5 months; 2.638 = 6 months; 3.324 = 7 months; 3.548 = 8 months; 1.714 = 9 months; 1.814 = 10 months; 3.231 = newborns.


Higher State Educational Establishment of Ukraine "Bukovinian State Medical University", Chernivtsi, Ukraine
Selective single data on the organometric parameters of the palm in the perinatal period of ontogenesis determines the relevance of the study. The purpose of the study is to establish the organometric parameters of the palm during the fetal and early neonatal periods of human ontogenesis. The study of the palm was performed on 51 preparations of fetal corpses (from 4 to 10 months) and 10 newborns using adequate anatomical methods: macropreparation, radiography, topographic and anatomical sections, morphometry, statistical analysis. It was found that the right hand in the perinatal period of ontogenesis is characterized by its elbow shape (54 %), for the left hand -radial (71 %). The parameters of the length of the right palm are greater than the parameters of the length of the left palm in the second trimester of fetal development and in the neonatal period; in the third trimester of fetal development the length of the left palm is greater than the length of the right. The parameters of the width of the right palm exceed these parameters of the left palm during the entire perinatal period of ontogenesis. During

Introduction
Unlike the anatomy of the lower extremity, in which the principle of connecting the individual parts, strengthening their connections, each component of the hand seeks to become free, each joint tries to get rid of its shackles, and each link -to get an individual sharpened shape. In the process of evolution of the three parts of the hand (shoulder, forearm and hand), its final (distal) part -the hand -acquired special significance. It becomes not only an executor of the will, but also a creator, an educator of the brain. It should also be noted that the human hand serves not only as a tool for physical manipulation, but also as an organ of cognition and communication. The human hand, as a complex formation of bones, ligaments, muscles, blood vessels and nerves, work in harmony to perform various and complex movements [1,2,10,11,15].
Information about the individual anatomical variability of the palm depending on the sex and age is necessary to develop optimal tactics of surgical interventions on it [4,6,7,14,19]. The newborn's palms have certain features and different organometric parameters compared to adults [8,20]. Unfortunately, in the modern scientific literature there is only selective single information about the organometric parameters of the palm in the perinatal period of ontogenesis [3,16].
The purpose of the study is to establish the organometric parameters of the palm during the fetal and early neonatal

BIOMEDICAL AND BIOSOCIAL ANTHROPOLOGY
Official Journal of the International Academy of Integrative Anthropology journal homepage: http://bba-journal.com periods of human ontogenesis.

Materials and methods
The study was performed on 51 preparations of fetal corpses (4 to 10 months) and 10 newborns of both sexes who died of causes not related to diseases of the musculoskeletal system and without external signs of anatomical abnormalities or anomalies and without obvious macroscopic abnormalities structure of the upper extremities. Adequate anatomical methods were used during the study: macropreparation, radiography, topographic anatomical sections, morphometry, statistical analysis [9].
Both fresh and fixed corpses of fetuses and newborns were used for macropreparation. The crown-heel length (CHL) of the fetus was measured before the study. In addition, the study involved some preparations of the upper extremity from the fund of the Department of Anatomy, Clinical Anatomy and Operative Surgery of the Higher Education Institution of Ukraine "Bukovynian State Medical University". Before the morphometric examination, each hand preparation was fixed on the polyfoam with hairpins. All measurements were performed using a centimeter tape and a compass rod.
For our studies, we used the following points of the hand: A (proximal point of the palm) -the middle of the distance between the elbow and radial surfaces of the wrist on the skin fold (the border between the wrist and the front surface of the forearm); B (end point of the palm) -the place of skin connection of III-IV fingers (the most distal part of the superficial transverse metacarpal ligament between III-IV fingers); G (middle point of the palm) -the most protruding part of the rise of the thumb along the line that runs along the border between the palm and the back of the hand; D (lateral point of the palm) -the thumb in pronation, the base of the first finger, which passes to the radial surface of the palm. The distance between points A and B determines the length of the palm, the distance between G and D points -the width of the palm (Fig. 1).
Statistical analysis of the obtained data was performed using a licensed program RStudio. The null hypothesis that the samples were taken from the same distribution or from distributions with the same medians was tested: Н 0 : {each group has the same distribution}, Н 1 : {each group does not have the same distribution}. We used the Student's test, the non-parametric Kruskal-Wallis test (answers the question of whether there is a difference between group distributions, but does not specify which groups differ), the Conover-Iman test to compare stochastic dominance and to obtain results between different pairwise comparisons after the Kruskal-Wallis test for stochastic dominance among k groups. When analyzing the sample correlation coefficient (r), the correlation strength was evaluated on the Chaddock scale: at r = 0 -no correlation; at r = from 0.1 to 0.3 -weak correlation; 0.3-0.5moderate force correlation; 0.5-0.7 -noticeable correlation; 0.7-0.9 -high power correlation, 0.9-1 -very high-power correlation. The values at p<0.05 were considered statistically significant. The

Results
It is established that in the perinatal period of ontogenesis the shape of the hand is determined by two forms depending on the length of the second and fourth fingers: elbow and radial. In the second trimester of fetal development for the right and left hand is characterized by a radial form, which occurs in 60 % and 82 % of cases, respectively, and the rest (40 % and 18 %) elbow. In the third trimester of fetal development, the elbow shape of the right hand is observed in 68 %, on the left hand -in 40 % of cases. The radial shape of the hand is found in 32 % on the right, on the left -in 60 % (Table 1).
During the perinatal period of ontogenesis, the length of the right palm increases from 11.70±0.31 mm (4-month-   Table 2). According to the results of the Conover-Iman test for the length of the right and left palms, the difference in medians for all possible age pairs is statistically significant, except for pairs for the right palm "8 months -9 months" and "10 months -newborns", for the left -"5 months -6 months" and "8 months -9 months".
The width of the right palm in the perinatal period of ontogenesis increases from 10.36±0.37 mm (4-monthold fetuses) to 22.26±0.31 mm (neonatal period), the leftfrom 9.600±0.341 mm to 21.81±0.37 mm (Table 3). According to the results of the Conover-Iman test for the width of the right and left palms, the difference in medians for all possible age pairs is statistically significant, except for pairs for the right palm "8 months -9 months", for the left -"5 months -6 months" and "8 months -9 months".
Correlation analysis between all organometric parameters of the right and left palms during the perinatal period of ontogenesis, using the Pearson correlation coefficient, found that the values of all paired correlation coefficients are positive and close to 1 (>0.85), indicating a close strong positive correlation between all organometric parameters.

Discussion
In the perinatal period of ontogenesis, the elbow shape is characteristic of the right hand (54 %), radial -for the left hand (71 %). With the age of the fetus, the percentage of the radial shape of the right and left hands decreases compared to the elbow shape.
Analyzing organometric data of the length of the right and left palms, we can state that in the second trimester of fetal development the parameters of the length of the right palm slightly exceed the parameters of the left palm, in the third trimester of fetal development the opposite of these parameters is found. In our opinion, this can be justified by the fact that for the third trimester of fetal development and for the newborn period for the right hand is characterized by its elbow shape. Organometric parameters of the length of the right and left palms increase the most from the 4th to the 5th month of fetal development and from the 7th month to the newborn period. In the period from the 5th to the 7th month of fetal development, these parameters increase slightly, this period can be called a period of delayed development.
The parameters of the width of the right palm during the perinatal period of ontogenesis are always slightly larger compared to the parameters of the width of the left palm. For the width of the right and left palms is characterized two periods of accelerated development, from the 4th to the 5th month of fetal development and from the 7th month to the newborn period. From the 5th to the 7th month of fetal development, the width of the right and left palms increases slightly.
Comparing the average values of all organometric parameters of the right and left palms in all age groups, using the Wilcoxon test, we can state that all p-values are greater than the significance level ?=0.05, which means no significant difference. Thus, based on the arithmetic mean of the right and left palms, it is possible to build models for predicting the normative values of organometric parameters of the palm during the perinatal period of ontogenesis, using the age of the fetus and its crown-heel length. Some evidence of a significant difference in mean values relative to the organometric parameters of the palm are given in the scientific works of Albay S. et al. [3], Ritterband-Rosenbaum A. et al. [16].
The model of palm length during the perinatal period of ontogenesis has the form: palm length = β 0 + 0.042 x crownheel length of the fetus, where β 0 = 3.587, if the age period = 4 months; 5.562 = 5 months; 4.071 = 6 months; 4.840 =   Modifications of the structure and shapes of the upper limb, in particular the hand, demonstrate a large number of variants, the etiological basis of which are complex and numerous processes of changes in embryonic development [5,12,13,17,18]. Interest in the anatomical features of the hand is due to the increase in the number of medical and diagnostic procedures that require direct access to the lower structures of the palm, considering the individual typological characteristics of patients.

Conclusions
1. For the right hand in the perinatal period of ontogenesis is characterized by its elbow shape (54 %), for the left hand -radial (71 %). The parameters of the length of the right palm are greater than the parameters of the length of the left palm in the second trimester of fetal development and in the neonatal period, in the third trimester of fetal development the length of the left palm is greater than the length of the right. The parameters of the width of the right palm exceed these parameters of the left palm during the entire perinatal period of ontogenesis.
2. During the perinatal period of ontogenesis, the organometric parameters of the palm are characterized by two periods of accelerated development and a period of relatively slow development. For the length and width of the right and left palms periods of accelerated development continue from the 4th to the 5th month of fetal development and from the 7th month to the neonatal period; from the 5th to the 7th month of fetal development -a period of relatively slow development.