Highlights
● The selected football practice and corrective movements significantly decreased body weight, waist, and hip circumference.
● The selected football practice and corrective movements improved postural deformities, forward head, kyphosis, lordosis, and genu varum in all groups.
Plain Language Summary
The effectiveness of performing football exercises and selected corrective exercises highlights those as a nonpharmacological method for improving body composition and the indicators of physical readiness and postural deformities in children, teenagers, and youth. Therefore, the exercises and follow-up courses are recommended to be longer for the participants. Different strength and stretching training with corrective moves are also advised to be investigated in all three groups of participants.
1. Introduction
Studies indicate that physical deformities among students are important [1]. These deformities which are not often severe can be improved by simple exercises. Although correct body posture is not adequate for being healthy, it includes a part of the general health of individuals [2]. Physical condition and posture are related to bio-psychological health [3]. Additionally, overweight in children is associated with musculoskeletal deformities [4]. Postural deformities are highly prevalent in Iran [5, 6]. In this regard, Daneshmandi et al. reported that 80.68% of students have spinal deformities which are more frequent in girls than boys [7].
Prevention is more important than treatment. Prevention also depends on teaching correct principles and maintaining correct postures to a great extent [8]. Appropriate methods for preventing and improving postural deformities include implementing physical activities, being capable of improving all affecting factors on physical readiness and health [9], and help the correction and maintenance of body posture through muscular balance [10]. Karimian et al. investigated the prevalence rate of postural deformities and its relationship with sports activities in 148 children. They reported a significant difference between the natural and unnatural posture of children.
There was also a significant difference between the number of skeletal deformities and sports activities in male and female children. According to them, lordosis had the highest prevalence rate in boys; lordosis and kyphosis were the highest and lowest prevalent complications in girls, respectively [11]. Emery et al. investigated the effect of 12 weeks of Pilates exercises performed twice per week for 60 minutes per session on the flexibility of 19 subjects. Their results indicated a significant improvement in kyphosis, increased neck power and flexibility in the upper chest area which can prevent the deformities of neck and shoulders [12].
Spinal postural deformities are highly prevalent; however, the correction of those have been neglected. Thus, improving physical posture by corrective exercises has been of researchers’ interest. Therefore, many people with kyphosis or lordosis can be contributed through corrective exercises to prevent deformities and the high costs of treatment. Proposing the desired profile about the prevalence of postural deformities in students can provide an opportunity to scientifically develop educational and corrective programs and ideally use the existing facilities and knowledge. Therefore, it is important to identify and investigate the deformities prevalence. We compared the prevalence rate of postural deformities in children, teenagers, and youth. Therefore, the current study aimed to compare the effect of eight weeks of selected football exercises and corrective movements on abnormalities, physical fitness factors and body composition in three different age groups, including children, teenagers, and youth.
2. Materials and Methods
This quasi-experimental study was conducted on three experimental groups. The statistical sample of this study included 60 football player students from Kazemiyan football college in Mashhad City, Iran, in 2018. The samples were selected through stratified simple random sampling method. The study participants were first familiarized with the nature and manner of cooperation with the study. The inclusion criteria were no substance intake, no smoking and being bio-psychologically healthy. The students voluntarily participated in the study and provided informed consent forms. They were then divided into children (n=20, Mean±SD age=12.25±0.78 y), teenagers (n=20, Mean±SD age=14.30±0.65 y), and youth (n=20, Mean±SD age=16.40±0.50 y) groups.
To evaluate the body compositions, the height of participants was measured by Seca Stadiometer (made in Germany) with a sensitivity of 5 mm, hip and waist circumference by band meter (Mabis, Japan) with a precision of 5 mm, weight by the digital scale (Beurer, Germany; model: PS07-PS06). Body Mass Index (BMI) was obtained by body weight divided by height squared (kg/m2). To measure the ratio of waist to hip circumference, band meter (Mabis, Japan) with a precision of 5 mm was used. The ratio of waist to hip circumference was determined by the division of minimum waist circumference and maximum hip circumference.
To measure postural deformities, a chessboard was used. The middle line of the chessboard with a distinctive color was considered as plummet which is a framework with the dimensions of 100×200 cm, longitudinally and latitudinally divided into 5-cm grid squares. The New York test and plummet were used for investigating forward head posture, rounded shoulder, kyphosis, scoliosis, piriformis, and lordosis. These tests are appropriate for determining any disorders in the lateral, posterior and anterior sides. Genu Varum was determined by the executors given the gaps between ankle and knee. Flat feet were evaluated measuring the foot arc height and hallux light from the foot length by the flow.
To evaluate the level of dorsal curvature (kyphosis angle), the study participants with bare torso comfortably stand backward (the eyes staring forward, the distance of feet is almost 15cm, and the hands hanging by sides, waiting for approximately 3 min; then, the measurement is conducted). The spinous process of T12 and T4 vertebrae are determined. Then, the flexible ruler is placed on the spinous process of T12 and T4 vertebrae, where it exactly matches the curvature of the study participant. Then, without changing the position, the ruler is placed on a paper and the surface curvature of the ruler placed on the skin is drawn.

Both ends of the curve are connected to create an L-shaped line; then, the most curved point on the back is connected to the L-shape to create an H-shaped line. Then, kyphosis angle is obtained through the formula in Figure 1. For a better validity, the back curve of each participant was measured twice by this method and the mean score of these 3 angles were considered [13]. Scores of ≥40° angle were considered as back hyperkyphosis.
The physiological indicators of this study included aerobic power (540 meters’ test), speed (36m sprint), anaerobic power (vertical or sergeant jump), explosive power (pair jump), muscular endurance (sit-ups), and general agility (4×9 meter test).
Each session of the program included symmetrical and asymmetrical stretching exercises.
Cat stretching
The goal was high length stretching the spinal cord and recovering its correct direction.
Sitting body rotation
The goal was active mobility; recovering correct direction of the spinal cord; and stretching rotator muscles.
One-way body stretching while lying on the side
The goal was passive stretching of the lateral muscles towards concavity.
Cat camel mobility
The goal was improving mobility and flexibility and increasing the deep sense in the muscles and spinal cord (mobility exercise).
Lying body stretching
The goal was improving the power, especially the endurance of extensor muscles; emphasizing on recovering the direction of the spinal cord (strength training with an emphasis on endurance).
Lateral flection of body while lying on the side
The goal was improving the power, especially the strength of lateral muscles and spinal rotators often towards curvature convexity.
Side or diagonal plank
The goal was improving the performance of muscles, especially in the central part of the body, and generally, the side muscles of the body with an emphasis on the contraction and increase of muscular strength; strengthening stability to recover and maintain the correct direction of spinal cord.
Complete plank
The goal was similar to number 7; however, the concentration is on the extensor and multifidus muscles [14].
The selected sports activities used in this study were specific to football, and practiced for 8 weeks, three times a week. The exercise program included a 10-min general warm up (walking, slow running, stretching moves and mobility), a 10-min particular warm up given the physiological and mental features, including short and speed starts, shuffle movements with a ball; and 10 starts of 10-15 meters. Then, the main football exercises were conducted for 45-60 min with an intensity of 60% to 75% of hearing bites; at the end of each session, the cool up (slow running, walking and stretching moves) were conducted for 10 minutes to return the body to the initial mood [15].
The collected data were analyzed by SPSS. After verifying the normal distribution of the obtained data, the Shapiro-Wilk test was used. In addition, the convergence of variances was examined by the Levene’s test; to compare the intergroup and intragroup mean scores, Analysis of Covariance (ANCOVA) was applied, and Tukey’s post hoc test was used to examine the differences between groups. The significance level was set at P<0.05.
3. Results
The characteristics and postural deformities of study participants are presented in Tables 1 and 2. As per Table 3, body weight, waist, and hip circumference significantly decreased in all groups of children, teenagers, and youth. However, BMI only significantly decreased in children and youth groups. The mean scores of intergroup changes were significantly different in all groups in respect of BMI, body weight, waist, and hip circumference. According to Table 4, the results of Tukey’s post hoc test indicated that there were significant intragroup differences in the mean scores of weight, BMI, waist, hip, and WHR between the three groups (P=0.001).
Table 5 reveals that physical readiness, cardiorespiratory endurance, anaerobic power, agility, muscular endurance, and muscular strength were statistically significant in all groups. The record of speed significantly decreased in the children and teenagers. The mean scores of intergroup changes were significantly different in all groups; the records of male students’ physical readiness significantly differed in physical readiness, cardiorespiratory endurance, anaerobic power, agility, muscular endurance, and muscular strength.

According to Table 6, the results of Tukey’s post hoc test suggested that the intragroup differences in terms of the mean scores of cardiovascular fitness, anaerobic power, speed, agility, and power were significant between all the three groups (P=0.001).

Based on Table 7, abnormalities such as forward head posture, kyphosis, lordosis, and Genu Varum were significant in all three age groups. Regarding the scoliosis variable, only two groups of children and teenagers had meaningful results. The mean score of changes in intermediate groups in the three age groups were significantly different between the three groups in forward head posture and Genu Varum.

According to Table 8, the results of Tukey’s post hoc test indicated that the intragroup differences in the mean scores of forward head posture were only significant between the children and teenagers groups (P=0.004). Scoliosis was only significantly different between the children and youth groups (P=0.028). Kyphosis was only significantly different between the children and youth groups (P=0.045).

According to the obtained results, body weight, waist, and hip circumference significantly decreased in all three groups. However, BMI only significantly decreased in children and youth groups. The obtained data are consistent with the results of Andersen et al. and De Campos et al. [16, 17], but inconsistent with the findings of Donnelly and associates [18]. Andersen et al. investigated the effects of 52 weeks of football and endurance exercises on unexercised men; they concluded that BMI significantly decreased and the muscular mass significantly increased in the samples [16].

De Campos et al. argued that the maximum level of energy and anaerobic power of participants significantly increased at the end of course; however, there was no significant change in body weight, BMI and body fat percentage [17]. In this case, race differences and the nutrition diet of participants have not been controlled; the level of pre-exercise physical readiness and the manner of body compatibility and the response of participants are very important. One of the most important reasons of reducing body composition is the increased fat oxidation by enhanced beta-oxidation enzymes and the Kreb’s cycle after exercise. Therefore, the increased fat metabolism in athletes decreases the rate of fat and improves the anthropometric factors in them [19].

During sport exercises, by the increase of epinephrine, norepinephrine, cortisol, and growth hormone, the endocrine system enhances the fat oxidation; also by the increase of recalling and use of free fatty acids, the energy is supplied; thus, the body mass will be reduced. Therefore, in addition to an increase in energy and fat oxidation, the intercellular changes of muscles and capillary network seem to be effective [20]. The level of cardiorespiratory endurance, anaerobic power, agility, muscular endurance, and muscular strength was statistically significant in all three studied age groups. The record of speed significantly decreased in children and teenagers.

The present study is consistent with the results of Shafabakhsh et al. [21], but inconsistent with the findings of Lesinski and colleagues [22]. Shafabakhsh et al. reported that cardiorespiratory endurance, flexibility, muscular endurance, and raw power have significantly improved in male students [21]. Lesinski et al. investigated the effect of football exercises on anthropometric features, body composition, and the physical fitness factors of young female football players. They concluded that BMI significantly increased and body balance and endurance improved in the subjects. There was no significant change in muscular power, speed, and changing the direction in speed. Muscle strength of knee extensor muscles decreased [22].

There was no significant change in muscular strength/endurance, speed, and directional change in speed. The muscle strength of thigh muscle was reduced [22]. The selected football exercises had significantly affected participants’ agility. Unlike the researchers’ idea regarding the ineffectiveness of exercising on agility, some studies reported that agility is affected by different muscular body types; thus, it can be considered as the compatibility of cardiovascular, muscular and metabolic systems to aerobic exercises.

The increase of maximum consumed energy and decrease of heart rate, and resting after exercise are probably because of the increased aerobic capacity of muscles, increased total hemoglobin, increased fat metabolism, increased end-diastolic volume, decreased end-diastolic volume, and increased impact volume. The increase in maximum oxygen can be due to the increased difference in arteriovenous oxygen, the increased activity of the Kreb’s cycle and the electron transfer system, the increased number and size of mitochondria, and increased muscular tissue and its efficiency [23, 24].

According to the obtained results, postural deformities, forward head posture, kyphosis, lordosis, and Genu Varum improved in all groups. The achieved results indicated that corrective exercises, including strength and stretching exercises, significantly affect people and its power section affects the muscular length, moves different skeletal parts, and causes the stability of ligaments. Stretching exercises are used for coordinating agonist and antagonist muscles and increase the length of involved muscles such as iliacus muscle and spine extensor [25]. Participating in stretching exercising increases the mobility of the lower limbs of individuals and age does not limit it. Therefore, stretching exercises are of a great role in returning the appropriate posture of muscles [26].

The most important factor in increasing muscular power is a neural system which will not be gained without the emergence of neural compatibilities. After exercising, neural compatibility is reflected through an improved neural coordination, the increased efficiency of mobilizing motor neurons, increased neural activation, the decreased inhibitory action of Golgi tendon organ, and the activation of passive or weak neural communications [27].

Compliance with ethical guidelines

The steps of tests were approved by the Ethics Committee of the Faculty of Humanities and Basic Sciences, Toos Institute of Higher Education.

This work was financially supported by Toos Institute of Higher Education.

All authors contributed in designing, running, and writing all parts of the research.

The authors declared no conflict of interest.

The authors would like to thank the subjects who participated in this study.

Norris CM. Back stability. Champaign: Human Kinetics; 2000.

Norris CM. Spinal stabilisation: Muscle imbalance and the low back. Physiotherapy. 1995; 81(3):127-38. [DOI:10.1016/S0031-9406(05)67068-X]

Daneshmandi H, Alizadeh MH, Gharakhaklou R. Corrective exercises. Tehran: SAMT; 2007.

Krul M, van der Wouden JC, Schellevis FG, van Suijlekom-Smit LW, Koes BW. Musculoskeletal problems in overweight and obese children. The Annals of Family Medicine. 2009; 7(4):352-6. [DOI:10.1370/afm.1005] [PMID] [PMCID]

Seneh A. [Comparison of the prevalence of abnormalities in upper limbs of male and female in male and female students of guidance school (Persian)]. Quarterly Journal of Educational Innovations. 2009; 30(8):139-56.

Heidari S, Moghadasi M. Effect of aerobic training intensity on irisin in streptozotocin-induced diabetic rats. Journal of Physical Activity and Hormones. 2018; 1(4):23-32.

Daneshmandi H, Pourhossein H, Sardar M. [Comparison of spinal abnormalities in boys and girls students (Persian)]. Harkat. 2006; 1383(23):143-56.

Penha PJ, João SM, Casarotto RA, Amino CJ, Penteado DC. Postural assessment of girls between 7 and 10 years of age. Clinics. 2005; 60(1):9-16. [DOI:10.1590/S1807-59322005000100004] [PMID]

Bullo V, Bergamin M, Gobbo S, Sieverdes JC, Zaccaria M, Neunhaeuserer D, et al. The effects of Pilates exercise training on physical fitness and wellbeing in the elderly: A systematic review for future exercise prescription. Preventive Medicine. 2015; 75:1-11. [DOI:10.1016/j.ypmed.2015.03.002] [PMID]

Patti A, Bianco A, Paoli A, Messina G, Montalto MA, Bellafiore M, et al. Effects of pilates exercise programs in people with chronic low back pain: A systematic review. Medicine. 2015; 94(4):e383. [DOI:10.1097/MD.0000000000000383] [PMID] [PMCID]

Karimian R, Karimian M, Hadipour M, Heyat F, Janbozorgi A. [The prevalence of children’s postural abnormalities and its association with sport activity (Persian)]. Journal of Fasa University of Medical Sciences. 2016; 6(1):106-12.

Emery K, De Serres SJ, McMillan A, Côté JN. The effects of a Pilates training program on arm-trunk posture and movement. Clinical Biomechanics. 2010; 25(2):124-30. [DOI:10.1016/j.clinbiomech.2009.10.003] [PMID]

Post RB, Leferink VJ. Spinal mobility: Sagittal range of motion measured with the SpinalMouse, a new non-invasive device. Archives of Orthopaedic and Trauma Surgery. 2004; 124(3):187-92. [DOI:10.1007/s00402-004-0641-1] [PMID]

Najafi H, Seidi F. [The effect of an eight week selected corrective exercises program on non-structural scoliosis deformity (Persian)]. Journal of Research Sport Rehabilitation. 2014; 2(3):11-9.

Hosseini SR, Hejazi K. The effects of Ramadan fasting and physical activity on blood hematological-biochemical parameters. Iranian Journal of Basic Medical Sciences. 2013; 16(7):845-49. [PMID] [PMCID]

Andersen TR, Schmidt JF, Pedersen MT, Krustrup P, Bangsbo J. The effects of 52 weeks of soccer or resistance training on body composition and muscle function in +65-year-old healthy males: A randomized controlled trial. PLOS One. 2016; 11(2):e0148236. [DOI:10.1371/journal.pone.0148236]

De Campos LC, de Athayde Costa A, dos Santos LT, Costa LT, Montagner PC, Borin JP, et al. Effects of training in physical fitness and body composition of the brazilian 5-a-side football team. Revista Andaluza de Medicina del Deporte. 2013; 6(3):91-5. [DOI:10.1016/S1888-7546(13)70041-8]

Donnelly JE, Hill JO, Jacobsen DJ, Potteiger J, Sullivan DK, Johnson SL, et al. Effects of a 16-month randomized controlled exercise trial on body weight and composition in young, overweight men and women: The Midwest exercise trial. Archives of Internal Medicine. 2003; 163(11):1343-50. [DOI:10.1001/archinte.163.11.1343] [PMID]

Farrell PA, Joyner M, Caiozzo V. ACSM’s advanced exercise physiology. Auckland, New Zealand: Wolters Kluwer Health Adis (ESP); 2011

Shad R, Bijeh N, Fathi M. [The effects of eight weeks of aerobic exercise on insulin resistance, body composition and aerobic power of overweight female students (Persian)]. Journal of Knowledge & Health. 2017; 12(2):17-24.

Shafabakhsh SR, Shafizadeh M, Dehkhoda MR. [Effects of training and fitness education on the health-related physical fitness factors in adolescent students: Evaluating the mediating role of knowledge and internal motivation (Persian)]. Research in Sport Management & Motor Behavior. 2012; 2(3):1-15.

Lesinski M, Prieske O, Helm N, Granacher U. Effects of soccer training on anthropometry, body composition, and physical fitness during a soccer season in female elite young athletes: A prospective cohort study. Frontiers in Physiology. 2017; 8:1093. [DOI:10.3389/fphys.2017.01093] [PMID] [PMCID]

Soori R, Ranjbar K, Jafarpour SH. [Effect of dose response relate to number of training sessions of physical fitness in sedentary adolescence boys (Persian)]. Sport Physiology. 2013; 5(17):13-27.

Janssen I, LeBlanc AG. Systematic review of the health benefits of physical activity and fitness in school-aged children and youth. International Journal of Behavioral Nutrition and Physical Activity. 2010; 7(1):40-55. [DOI:10.1186/1479-5868-7-40] [PMID] [PMCID]

Kratěnová J, ŽEjglicová K, Mal M, Filipová V. Prevalence and risk factors of poor posture in school children in the Czech Republic. Journal of School Health. 2007; 77(3):131-7. [DOI:10.1111/j.1746-1561.2007.00182.x] [PMID]

Zakas A, Galazoulas C, Grammatikopoulou MG, Vergou A. Effects of stretching exercise during strength training in prepubertal, pubertal and adolescent boys. Journal of Bodywork and Movement Therapies. 2002; 6(3):170-6. [DOI:10.1054/jbmt.2001.0275]

Enoka RM. Muscle strength and its development. Sports Medicine. 1988; 6(3):146-68. [DOI:10.2165/00007256-198806030-00003] [PMID]