The human foot is an important part of the static-dynamic motor organ and is shaped uniquely in each individual. Its construction and setting have major impacts on the quality of gait and postural stability. A properly arched foot is elastic and flexible and absorbs microtrauma and shocks during locomotion, making the gait light and springy [
Down syndrome (DS), also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21 [
The aim of this study was the analysis of selected features of the foot structure in boys with DS versus their age- and gender-matched peers without Down syndrome.
The study included 30 boys with DS (16 were 14-year-olds and 14 were 15-year-olds) attending the Special Purpose School and Education Center in Mrowla, the Special Purpose School and Education Center in Ropczyce and UNICEF Special Schools Complex in Rzeszow (Poland). The inclusion criteria were a confirmed genetic diagnosis of Down syndrome by a pediatric neurologist, age between 14 and 15 years, physical fitness that allowed for walking without orthopedic equipment, and the ability to take a standing position on the podoscope independently. In addition, understanding the instructions that were necessary for the measurement procedures and written consent of parents or guardians to participate in the study were also criteria. The exclusion criteria included a previous orthopedic surgery. A control group consisting of 30 age- and gender-matched peers attending junior high school in the School Complex in Swilcza (Poland) without Down syndrome or cognitive disorders and without signs of orthopedic disease were also recruited for this study.
The CQ-ST podoscope (manufactured by Electronic System) was used as the main research tool. The podoscopic examination of the plantar side of the foot is the development and improvement of the well-known plantographic method. In addition to an exact foot print, we obtained information about the foot arching. The study entailed measuring of the plantar feet surfaces in a relaxed stance, with the upper limbs hanging along the body. Each time, both feet were subjected to examination. The width and foot angle were natural, unforced (Figure
Podoscopic survey sample. Source: own study. The authors obtained the participant’s parent consent to publish the image.
The following parameters were measured: foot length: the length of the segment connecting the most distal point of the forefoot (on the pad of the longest toe) with the farthest point within the hindfoot, in cm; foot width: the length of the segment connecting the most medially located point on the head of the first metatarsal bone (metatarsale tibiale: mtt) with the point lying most laterally on the head of the V metatarsal bone (metatarsale fibulare: mtf) in cm; Clarke’s angle: constructed by drawing a tangent to the medial edge of the foot (the prints) and a line connecting the deeper part of the footprint with the most medial point of the forefoot, in degrees; the Wejsflog hallux valgus angle ( the angle of the varus deformity of the fifth toe (
The procedures for calculating the feet structure indices are shown in Figure
Procedure for determining the feet structure indices: (a) foot length
Anthropometric measurements of the body mass and height were taken. The body mass was measured with electronic scales, determined to the nearest 0.1 kg. The body height was measured to the nearest 0.1 cm using a Martin-type anthropometer. The obtained data were used to calculate BMI. Basic descriptive statistics of the somatic features in the examined boys are presented in Table
Comparison of somatic features recorded for the DS group and control group.
Age |
DS group | Control group |
|
| ||||
---|---|---|---|---|---|---|---|---|
|
Me | Max–min | |
Me | Max–min | |||
Body weight [kg] | ||||||||
14 | 49.56 ± 10.11 | 46.50 | 67.00–33.00 | 56.06 ± 12.85 | 53.00 | 81.00–35.00 |
|
0.122 |
15 | 68.43 ± 6.91 | 69.50 | 81.00–58.50 | 63.39 ± 9.17 | 58.25 | 85.00–55.00 |
|
|
|
||||||||
Body height [cm] | ||||||||
14 | 149,44 ± 6,81 | 151.50 | 157.00–137.00 | 170.06 ± 9.84 | 171.00 | 185.00–149.00 |
|
<0.00 |
15 | 164,57 ± 5,46 | 164.00 | 172.00–155.00 | 176.86 ± 4.93 | 176.50 | 184.00–164.00 |
|
<0.00 |
|
||||||||
BMI | ||||||||
14 | 22.24 ± 4.48 | 20.91 | 30.47–17.31 | 19.25 ± 3.53 | 17.84 | 27.01–15.58 |
|
|
15 | 25.28 ± 2.52 | 25.97 | 28.49–20.03 | 20.26 ± 2.73 | 18.50 | 26.81–18.15 |
|
|
In order to preserve the integrity of the research process, all the measurements were taken in the gym, in the morning, using the same measuring instruments operated by the authors. Boys were wearing their gymnastic uniforms without shoes. Procedures were carried out in accordance with Declaration of Helsinki for experiments involving humans. All participants, their parents, or legal guardians received detailed information concerning the aim and methodology used in the study. The study was approved by the Ethical Review Board of the Rzeszow University (number 6/01/2015) and performed after obtaining written consent from the children’s parents or legal guardians.
Based on the accumulated data, the following descriptive statistics were calculated: arithmetical mean value
Table
Comparison of foot structure parameters recorded for the DS group and control group.
Age |
DS group | Control group |
|
| ||||
---|---|---|---|---|---|---|---|---|
|
Me | Max–min | |
Me | Max–min | |||
Length of the right foot [cm] | ||||||||
14 | 20.98 ± 0.98 | 20.90 | 22.50–19.30 | 24.40 ± 1.34 | 24.35 | 26.50–21.50 |
|
<0.00 |
15 | 23.12 ± 1.59 | 23.25 | 26.00–20.50 | 25.39 ± 0.60 | 25.20 | 26.90–24.70 |
|
<0.00 |
|
||||||||
Length of the left foot [cm] | ||||||||
14 | 20.86 ± 0.92 | 20.60 | 22.50–19.40 | 24.48 ± 1.35 | 24.20 | 26.90–21.50 |
|
<0.00 |
15 | 23.14 ± 1.69 | 23.10 | 26.50–20.90 | 25.52 ± 0.74 | 25.30 | 26.90–24.50 |
|
|
|
||||||||
Width of the right foot [cm] | ||||||||
14 | 8.27 ± 0.64 | 8.45 | 9.20–7.10 | 8.89 ± 0.89 | 8.90 | 10.70–7.50 |
|
|
15 | 8.62 ± 0.50 | 8.70 | 9.30–7.50 | 8.87 ± 0.67 | 8.90 | 9.90–8.00 |
|
0.274 |
|
||||||||
Width of the left foot [cm] | ||||||||
14 | 8.42 ± 0.55 | 8.60 | 9.30–7.20 | 8.99 ± 0.78 | 8.90 | 10.30–7.50 |
|
|
15 | 9.01 ± 0.70 | 9.10 | 10.10–7.60 | 9.03 ± 0.70 | 9.05 | 10.20–8.00 |
|
0.958 |
|
||||||||
Clarke’s angle of the right foot [°]—the medial longitudinal foot arch | ||||||||
14 | 21.06 ± 11.32 | 20.50 | 38.00–4.00 | 42.88 ± 9.46 | 41.00 | 56.00–16.00 |
|
<0.00 |
15 | 20.36 ± 9.99 | 18.50 | 34.00–3.00 | 38.79 ± 8.32 | 40.00 | 50.00–20.00 |
|
<0.00 |
|
||||||||
Clarke’s angle of the left foot [°]—the medial longitudinal foot arch | ||||||||
14 | 19.50 ± 9.65 | 19.50 | 38.00–3.00 | 41.81 ± 9.81 | 40.50 | 55.00–14.00 |
|
<0.00 |
15 | 19.00 ± 12.30 | 19.00 | 50.00–4.00 | 36.50 ± 6.45 | 37.00 | 45.00–18.00 |
|
<0.00 |
|
||||||||
Wejsflog |
||||||||
14 | 2.54 ± 0.22 | 2.55 | 2.87–2.10 | 2.75 ± 0.22 | 2.71 | 3.00–2.30 |
|
|
15 | 2.68 ± 0.17 | 2.73 | 2.92–2.36 | 2.84 ± 0.16 | 2.85 | 3.00–2.60 |
|
|
|
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Wejsflog |
||||||||
14 | 2.48 ± 0.19 | 2.47 | 2.86–2.20 | 2.73 ± 0.18 | 2.79 | 3.00–2.35 |
|
|
15 | 2.57 ± 0.16 | 2.59 | 2.79–2.27 | 2.81 ± 0.16 | 2.84 | 3.00–2.59 |
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|
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Hallux valgus angle ( | ||||||||
14 | 5.81 ± 5.82 | 4.00 | 20.00–0.00 | 3.12 ± 4.47 | 1.50 | 16.00–0.00 |
|
0.094 |
15 | 3.36 ± 3.63 | 2.00 | 10.00–0.00 | 3.79 ± 3.26 | 4.00 | 9.00–0.00 |
|
0.769 |
|
||||||||
Hallux valgus angle ( | ||||||||
14 | 7.81 ± 6.36 | 6.50 | 25.00–0.00 | 4.00 ± 4.56 | 2.00 | 14.00–0.00 |
|
0.056 |
15 | 6.07 ± 6.44 | 4.00 | 22.00–0.00 | 5.64 ± 4.18 | 5.50 | 13.00–0.00 |
|
0.804 |
|
||||||||
The V toe varus deformity angle ( | ||||||||
14 | 4.00 ± 5.72 | 0.00 | 16.00–0.00 | 15.25 ± 7.06 | 17.00 | 24.00–0.00 |
|
<0.00 |
15 | 9.93 ± 5.08 | 9.50 | 18.00–0.00 | 15.64 ± 6.82 | 16.50 | 26.00–0.00 |
|
|
|
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The V toe varus deformity angle ( | ||||||||
14 | 3.13 ± 4.99 | 0.50 | 17.00–0.00 | 13.25 ± 6.41 | 13.00 | 23.00–0.00 |
|
<0.00 |
15 | 7.00 ± 7.37 | 7.50 | 22.00–0.00 | 14.79 ± 5.04 | 14.00 | 26.00–6.00 |
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Issues concerning the construction of the foot have been repeatedly discussed by various authors. Many of them highlighted the correlation between insufficient movement, improper footwear, and excessive static loads with the foot structure. There are studies in the literature in which authors undertook the issues of foot structure in children and adolescents with developmental disorders. Concolino et al. [
The issue of the impact of the degree of intellectual disability on the longitudinal arch of the foot in 80 residents of Special Leeds Education Center in Tarnow (Poland) was described by Jankowicz-Szymanska et al. [
The research for our study showed that the feet of boys with DS are shorter and narrower compared to their healthy peers. There was a clear flattening of the dynamic foot arch. Also, in terms of the transverse arch, determined based on the ratio between the length and width of the foot, the boys with DS achieved worse results. The cause of the reduction of longitudinal and transverse arch rates may be abnormal function of the muscles and ligaments and excessive body weight. In turn, the comparison of the hallux valgus angle showed no intergroup differences and, more important, the average values of these angles are within the normal range in both groups. This leads to the conclusion that hallux valgus angle is not the most important feature differentiating the shape of the foot in the boys with DS and their healthy peers. It is worth noting that, in terms of the V toe setting, boys in the control group had poorer results. The tendency to a more pronounced varus of the V toe may be due to the increased load on the edge side of the foot. The analysis of literature related to the subject allowed us to note that most authors focused on assessing the formation of the longitudinal foot arch and hallux settings. This article is an attempt to conduct a comprehensive analysis of foot shape in boys with DS. Efforts were made to make the groups uniform, particularly for age (the results were analyzed separately for 14- and 15-year-olds) and gender. This approach justifies Demczuk-Włodarczyk’s [
Analysis of an extensive literature and the results of feet research point to the need to refer children and adolescents with DS to appropriate therapeutic procedures, which should include exercises aimed at strengthening the muscle around the foot joints and improving the stability of joints and proprioception, starting with static tasks and then adding exercises in dynamic conditions. The foot is one of the links in the proprioceptive kinetic chain of a man. Therefore, activities should be focused on exercises affecting the entire organ of movement and body posture. Improvement should take into account such specialized methods as Proprioceptive Neuromuscular Facilitation (PNF), kinetic control, and sensory integration, as well as general fitness exercises, swimming, and physical therapy. It is important to implement orthotics and proper footwear to stabilize and relieve overburdened parts of the feet. It is necessary to constantly monitor the state of the foot in order to modify the therapeutic treatment as needed. According to a holistic approach to the patent and his complex problems, physiotherapeutic issues should be treated in an interdisciplinary way. This implies the need to connect a variety of methods of enhancing motor skills, psychopedagogy, and various forms of social adaptation. The influence of environmental factors is equally important, especially through the education of families regarding proper diet of the patient, the importance of daily physical activity, and the selection of appropriate footwear.
The feet of boys with DS are shorter and narrower and longitudinally and transversely flatter compared to the feet of healthy peers. The hallux valgus angle is not the most important feature differentiating the shape of the foot in boys with DS and their healthy peers. In terms of the V toe setting, boys in the control group showed poorer results. Specialized therapeutic treatment in children and adolescents with DS should primarily involve exercises to increase the muscle strength around the foot joints, enhancing the stabilization in the joints and proprioception, as well as introducing orthotics and proper footwear. It is also necessary to constantly monitor the state of the foot in order to modify undertaken therapeutic conduct.
The authors declare that there are no conflicts of interest regarding the publication of this paper.