Understanding the assessment of biological maturation
Entendiendo la evaluación de la maduración biológica
Compreender a avaliação da maturação biológica
Mr. Janfer Fernandez
Ed. S. Osvaldo Leopoldo Fernandez
*Bachelor Degree in Physical Education Sport and Fitness
Master Degree in Kinesiology and Sport Science
Florida International University
**Bachelor Degree in Physical Educations Sport Science
Master in Methodology and theory of training for high performance athletes
Specialist Degree in Cycling Specialist Degree Track and Field
Universidad de las Ciencias la Cultura Física y el Deporte, en la Havana, Cuba
Reception: 11/09/2017 - Acceptance: 03/29/2018
1st Review: 03/24/2018 - 2nd Review: 03/24/218
The reason of this research paper is to review the literature that is applied to understand how to analyze the biological maturation assessment in athletes at young ages.The methods used to estimate biological maturity are skeletal maturity, sexual maturity, somatic or morphological maturity, and dental maturity. Among all these methods, skeletal maturation seems to be the most used, and its importance comes from the need of obtaining how ossified the bones are, to know the biological age among young athletes. Sophisticated methods of measuring biological maturity are still costly which make it hard for the practitioner to afford it. Physical Education coaches should prevent grouping students with difference in biological maturation to match up in collisional sports. Indirect assessment should be implemented any time is possible, like at the beginning of the school year, and past the half of the year.
Keywords: Skeletal maturity. Sexual maturity. Somatic or morphological maturity. Dental maturity. Percentage of loading.
La razón de este trabajo de investigación es revisar la literatura que se aplica para entender cómo analizar la evaluación de maduración biológica en atletas en edades tempranas. Los métodos utilizados para estimar la madurez biológica son madurez esquelética, madurez sexual, madurez somática o morfológica y madurez dental. Entre todos estos métodos, la maduración esquelética parece ser la más utilizada, y su importancia viene de la necesidad de obtener cómo los huesos osificados los huesos son realmente conocer la edad biológica entre los atletas jóvenes. Métodos sofisticados de medición de la madurez biológica siguen siendo costosos que hacen que sea realmente difícil para el profesional de pagarla. Los profesores de Educación Física deben evitar agrupar a los estudiantes con diferencias en la maduración biológica para que coincidan con los deportes de colisión. La evaluación indirecta debe ser implementada en cualquier momento posible, como al principio del año escolar, y después de la mitad del año.
Palabras clave: Madurez esquelética. Madurez sexual. Madurez somática o morfológica. Madurez dental. Porcentaje de carga.
O motivo deste trabalho de pesquisa é revisar a literatura que é aplicada para entender como analisar a avaliação da maturação biológica em atletas em idades jovens. Os métodos usados para estimar a maturidade biológica são maturidade esquelética, maturidade sexual, maturidade somática ou morfológica, e maturidade dental. Entre todos esses métodos, a maturação esquelética parece ser a mais utilizada, e sua importância vem da necessidade de se obter a consistência óssea, para se conhecer a idade biológica entre os jovens atletas. Métodos sofisticados de medir a maturidade biológica ainda são caros, o que torna difícil para o praticante pagar por isso. Os professores de Educação Física devem evitar que o agrupamento de alunos com diferença na maturação biológica corresponda aos esportes de colisão. A avaliação indireta deve ser implementada sempre que possível, como no início do ano letivo e após a metade do ano.
Unitermos: Maturidade esquelética. Maturidade sexual. Maturidade somática ou morfológica. Maturidade dentária. Porcentagem de carregamento.
Lecturas: Educación Física y Deportes, Vol. 22, Núm. 238, Mar. (2018)
In the world of sports and physical activities (PA), we see young athletes of the same age, but with a different somatotype. Sports that have these differences are Baseball, Soccer, Archery, and Basketball at young ages, and others.Through time, we know that chronological age is defined by the number of year we have lived since we were born. We also know that biological age refers to the extent of physiological changes that occurs while we develop in life. As children develop, they do not have the same biological age. Considering this, it is acceptable to say that two children of the same chronological may differ on their biological age.
With these perspectives, Sport Coaches (SC), and Physical Education Coaches (PECs) should base their knowledge when they want to make groups for playing and participating on contact physical activities (PAs). Collisions laws in physics dictates that if two object of different masses collapse, after the collision; the object with the smallest mass will take the same velocity and weight from the impacted object. This means that the smallest object will have more damage than the heavier object. This physic explanation demonstrates what could happen if two boys of same age, but different biological maturity collapse on the PE area, or training field. So, by grouping students by biological age instead by chronological age, PECs will make a better choice of the care of students while working in contact sports.
The information just said is very important in the world of sports, especially in sports and children. Coaches consider learning the changes of development in the child, so that they can expect normal behavior, body changes, emotional reaction to losses or victory, and know how to manage them (De Sanctis et al., 2016; Camargo et al., 2013; Fleta et al., 2000, & Clark, 1960).In addition, a deeper understanding of these ideas will give coaches the characteristics of individuals, so they can create good periodization of training, programs, that aim to a long plan development, not just the immediate development.The reason of this research paper is to review the literature that is applied to understand how to analyze the biological maturation assessment in athletes at young ages.
In order to create this literature review, several research databases were examined thoroughly. Those databases were PubMed, Cinahl, Eric, Medline, EBSCO Host, and Sport Discus. We searched for the following terminologies: biological maturation status, skeletal maturation system, sexual mature child,somatic and morphological maturation identification, sport participation, and conditioning for young athletes. Forty research reports were designated as having a good chance of being used. From those, only fifteen were the ones that best correspond our basic needs. Individual journals and books were investigated, such like Revista Andaluza de Medicina del Deporte, Journal of Gerontology, Act Biomedical Journal, Journal of Human Kinetics, Paediatric Exercise Science and Medicine (2nd ed.), and Human Growth (2nd ed.).
Most common method used to assess biological age
As we know, students and athletes have been grouped by chronological age for a long time, which makes it difficult to be effective when training with bigger groups. So, maturation differences must be known within a group if coaches want to state the differences among athletes. The methods used to estimate biological maturity are skeletal maturity, sexual maturity, somatic or morphological maturity, and dental maturity.
Among all these methods, skeletal maturation seems to be the most used (Lloyd et al., 2014) states that skeletal age maturation refers to the development and maturation of skeletal tissue. In their brief review, this group of authors help us understand the different methods used nowadays. One of skeletal maturation method used is the Greulich-Pyle Method. This method is uses the left hand and a radiograph that compares the skeletal maturation of children against those in an X-Ray plate maturation standard. According to Lloyd et al. (2014), skeletal maturity will be assess depending on how close to the standard age of bone maturation the child is. This method has shown to be weak on demonstrating differences of development among ethnicities.
Another common method for evaluating skeletal development and maturation is the Tanner-Whitehouse (TW) method. This method has been reviewed already 3 times calling them the TW1, TW2, and TW3. This method assesses specific bones of the wrist and hand and it measures from the initial ossification to total unions of the bones.Based on Lloyd et al. (2014), TW3 measures 13 bone assessment including the radius, ulna, and phalanges; or the 20-bone assessment incorporating the radius, ulna, phalanges, and carpals). The radiograph of each individual bone is analyzed separately and added together so the skeletal age can be obtained. Even being a validated measurement, the TW can underestimate girls and boys of 12-13 years of age. The last method mentioned by Lloyd et al. (2014) in their brief review is the Fels method. This is another method that relies on bone specific. This method measures the radius, ulna, carpals, metacarpals, and phalanges looking for the width and length of epiphysis and the metaphysis of the long bones, then it grades the results based on sex differences and age. Fels method has shown great validity in girl’s teenagers, but it has shown no accuracy with boys. According to Lloyd et al. (2014), the aforementioned methods have shown a great validity through time, but they are costly, need a specialist for the equipment, and issues have come up for the use of too much radiations.
The second method used to evaluate biological age is sexual maturity. This characteristics maturation assessment was created from the work of Tanner naming the five different stages (TS1, TS2, TS3, TS4, and TS5) of secondary sex characteristics. Armstrong and Van Mechelen (2009) in their book Paediatric Exercise Science and Medicinestated that the study of secondary sex characteristics goes from early embryonic differentiation to full maturity of the organs and fertility. The secondary characteristics viewed by this method are for the male's pubic hair and genital development, and for the female are breasts, pubic hair, and menarche. Even this is a great method to use, it has some disadvantage like not knowing the time of maturation within the stage, or how different are adolescents within the same stages of development. Specifically, in girls, the menarche which is the first menstruation period, must be assess in retrospective which means to ask the girls when was the first menstrual period they had. This assessment limits its use in sport settings, due to according to Lloyd et al. (2014), a girl who is premenarcheal does not necessarily suggest that she is also prepubertal. The Center for Disease Control and Prevention made public the work of professor James M. Tanner and the different secondary sex characteristics in maturation. According to James M. Tanner, starting with the boys’ development of external genitalia, stage 1 occurs at the prepubertal years. In stage 2, there is an enlargement of scrotum and testes; scrotum skin reddens and changes in texture. Stage 3 there is an enlargement of penis (length at first); further growth of testes. At the stage 4, the penis increases in size with growth in breadth and development of glans; testes and scrotum larger, scrotum skin darker; until it gets to adult’s genitalia at stage 5. Girls show a similar path in which stage 1 for breast development shows the prepubertal years. In addition, stage 2 happens when breast bud stage with elevation of breast and papilla; enlargement of areola. Following, the stage, there is a further enlargement of breast and areola; with a no separation of their contour. At stage 4, areola and papilla form a secondary mound above level of breast, that continues to stage 5 (mature stage) in which there is a projection of papilla only, related to recession of areola. To conclude, boys' and girls’ pubic hair development, stage 1 occurs at the prepubertal years. Stage 2 happens when sparse growth of long, slightly pigmented hair, straight or curled, at base of penis or along labia. In stage 3, there is a darker, coarser and more curled hair, spreading sparsely over junction of pubes. At stage 4, there are hair adult in type, but covering smaller area than in adult; no spread to medial surface of thighs, until stage 5, in which adult in type and quantity, with horizontal distribution ("feminine").
The assessment of somatic or morphological age can also give us some insight of biological maturation. Based on Freitas et al. (2014), “Somatic growth is based on change in dimension that occur in our body as we develop such as growth, peak high velocity (PHV), and how they relate to final adult stature”. The growth spurt rates can be assessed by traditional assessment of skin folds calculations, breadths, widths, specific landmarks, and stature.In addition, the growth spurts according to Armstrong and Van Mechelen (2009) is classified in 2 phases: the first one is at onset of adolescent growth curve, the second one is at the point of maximal PHV. It is interesting to notice that girls enter the second phase mentioned by Armstrong and Van Mechelen (2009) at ages of 11-12 years whereas boys enter at 13-14 years of age. Also, it is important to remember that later maturers will take at least a year more to enter this phase whilst early mature already entered a year before. To the struggle of predicting PHV, Mirwald et al. (2003), in a research called “An assessment of maturity from anthropometric measurements” published by the Medicine and Science in Sports and Exercise Journal, identified a few equations that may predict the peak height velocity. This work was also cited by Lloyd et al (2014) who explained that to predict PHV it is necessary to have the chronological age (years and months), body mass, standing height, and seated height. Taken from the study of Lloyd et al (2014):
Numerous studies have been conducted with the intention to know and predict the differences in somatic age variation between rural and urban children. In a research project from 2011-2013 performed by Dorota et al. (2013), the participants were 1,057 boys and girls, whose average age was 5.87 (±0.30) years in which 742 lived in the city and the rest lived in the rural area. Dorota et al. (2013), tested somatic development by measuring the height and weight, 3 circumferences (shoulder, chest and waist), and 5 skin folds (above the biceps and triceps, subscapular, on the stomach and on the calf). Results indicated that average values of height and weight, and body circumferences were lower in urban areas. Dorota et al. (2013) stated that differences in circumferences of chest and waist to the advantage of children in rural areas have proved to be significant in both sexes, and of the arm – in boys. The average values of skin folds in the tested environments were similar (Dorota et al. 2013). There is not a definite answer to the results obtained in this study. This topic is still growing among the pediatric scientists that look to define an absolute reality to these differences.
The last method mentioned above is the dental maturity assessment. Demirjian develop a scale of dental maturity based on the principle of Tanner-Whitehouse method to measure skeletal age (Armstrong and Van Mechelen 2009). In their brief review, De Sanctis et al. (2016) explained that dental maturity is easy to assess because it does not get affected by environmental factors, malnutrition, or illness. Pereira-Viera (2001), stated that stage A represents the beginning of mineralization of separate cusps, stage B appears after fusion of cusps, stage C means dentinal deposits, in stage D the formation is completed, stage E the root length is less than the crown height, stage F the root length equals to or exceed the crown height, stage G the walls of the root canal are parallel and its apical end is still opened, and stage H the apical formation is completed. De Sanctis et al. (2016) concluded that dental age is a fast, and not very influenced by intra- and interobserver error method, but ethical concerns are starting to question the use of radiation in children of so young ages.
Analysis of biological age and how it influences sports’ participations
As it was mentioned,biological age differs among athletes of the same team, and coaches need to know those differences to prepare and dosify training intensities, if the intent is to maximize the positive effect of the session.The review of literature presented here so far, gave us an example of how biological age is measured in pediatric and youth sport world. It was analyzed the most common methods used for assessing biological age and compared among young athletes of different levels of development.
From the review, it is worth to mention the methods that the authors used to perform and conduct their research. It seems that most method used to measure biological age, as stated above are skeletal maturity, sexual maturity, somatic or morphological maturity, and dental maturity. For the skeletal maturity, the above review showed that Greulich-Pyle, Tanner-Whitehouse (TW), and Fels method are the most used. Sexual maturity uses the 5 stages of secondary sex characteristic methods used by professor Tanner. The secondary sexual characteristics that are evaluated are for the male's pubic hair and genital development, and for the female are breasts, pubic hair, and menarche. Morphological maturity in this work was evaluated by reviewing what Armstrong and Van Mechelen (2009), Mirwald et al. (2003), and Lloyd et al. (2014) used to conduct their studies. The assessments used are the traditional skin folds calculations, breadths, widths, specific landmarks, and formulas for predicting stature. The last method of assessing biological maturity mentioned in the review was dental maturity. Pereira-Viera (2001), stated that Demirjian created a scale that is linked to the 5 Tanner stages. Later, De Sanctis et al. (2016) concluded that dental age is a fast, and not very influenced by intra- and interobserver error.
The reason of this research paper is to review the literature that is applied to understand how to analyze the biological maturation assessment in athletes at young ages. It was shown the methods that are used on the field to analyze biological maturity are skeletal maturity, sexual maturity, somatic or morphological maturity, and dental maturity. In addition, as stated above, biological maturation can affect or favor the way athletes participate in organized sports. Skeletal maturation methods seemed to be used the most on the field. Besides being reliable on their own way, skeletal maturity methods are costly. Greulich-Pyle Method uses the left hand and radiographs that compares the skeletal maturation of children against those in an X-Ray plate maturation standard. The Tanner-Whitehouse (TW) method measures 13 bone assessment including the radius, ulna, and phalanges; or the 20-bone assessment incorporating the radius, ulna, phalanges, and carpals). The radiograph of each individual bone is analyzed separately and added together so the skeletal age can be obtained. Other method mentioned was the sexual maturity, which assesses throw the secondary sexual characteristics which are the male's pubic hair and genital development, and for the female are breasts, pubic hair, and menarche. Somatic method of growth was also analyzed. This method is based on change in dimension that occur in children’s body as they develop such as growth, peak high velocity (PHV), and how they relate to final adult stature. The changes through the life span can be assessed by traditional assessment of skin folds calculations, breadths, widths, specific landmarks, and stature. Last, but not least, dental maturation has also been a resource for evaluating biological maturity. As stated above, dental maturation is measured through stages of development, but ethical concern is starting to question the use of radiation in children of so young ages.
The results of this brief review show that direct measurement of biological age through time have more validity that indirect measurement, but they are costly. A simple trainer most of the time cannot assess athlete’s skeletal maturity for just measure the difference in biological maturity. The reason why it is important to measure skeletal maturity is because it gives us an idea of how ossified bones are, which later is related to injury prevention. Numerous studies have been performed baseball pitching biomechanics and velocities. They have indicated that as we mature as we become so does the Ulnar collateral ligament, which is very important for pitchers’ health. The results of this review help us understand that stature equations are indirect measurements that coaches may need to assess future height in kids. In addition, traditional anthropometric measurements are very reliable on the field, since they have a low cost and can be done any time. Findings of this review can serve coaches in some ways. For example, it should exist a close follow up from the coaches to those athletes at pre-pubertal, pubertal, and post-pubertal. Physical Education coaches should prevent grouping students with difference in biological maturation to match up in collisional sports. Indirect assessment should be implemented any time is possible, like at the beginning of the school year, and past the half of the year to measure progress or delay. Parents should be advice when delays occur at any point of the school year. In relevance to sport settings, coaches should delimitate different percentage of loading of those that are little behind in development and put an extra effort for the technique development. It is important to notice that “Low maturation status may affect psychology on the young adults by feeling inferior to their peers” (Peres-Klug, Santos da Fonseca, 2006; Malina, 1990 & Malina, 1988).
The reason of this research paper is to review the literature that is applied to understand how to analyze the biological maturation assessment in athletes at young ages.I analyzed by reviewing the latest and most reviewed literature found in SportDiscus.As Beunen and Malina (2008), stated, it is clear now that long term development must be taken cautiously when training early and late maturers. It is my opinion that future works on research should focus on how dosify the loading and differences in training methodologies for early and late maturers. According to Bielicki (1986, p. 284), “sophisticated methods of measuring biological maturity are still costly which make it hard for the practitioner to afford it”. Implications of this study suggest that anthropometric measurements and somatic formulas, even though are indirect measurements are still respectively used on the sport and pediatric field.
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Lecturas: Educación Física y Deportes, Vol. 22, Núm. 238, Mar. (2018)