G Model MAT-6230; No. of Pages 7
ARTICLE IN PRESS Maturitas xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Maturitas journal homepage: www.elsevier.com/locate/maturitas
Gender and age related differences in foot morphology Daniele Tomassoni a,∗ , Enea Traini b , Francesco Amenta b a
Scuola di Bioscienze e Medicina Veterinaria, Università di Camerino, 62032 Camerino, Italy Centro di Ricerche Cliniche, Telemedicina e Telefarmacia, Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, 62032 Camerino, Italy b
a r t i c l e
i n f o
Article history: Received 18 April 2014 Received in revised form 29 July 2014 Accepted 30 July 2014 Available online xxx Keywords: Foot anatomy Age-dependent changes Quantitative morphology Elderly Footwear
a b s t r a c t Objective: This study has assessed age-related changes of foot morphology for developing appropriate footwear with particular reference to the elderly. Methods: Anatomical parameters such as foot length, circumference and height and ankle length, circumference and height were assessed in a sample of males (n = 577) and females (n = 528) divided into three age groups. The groups included young-adult, aged between 20 and 25 years; adult, aged between 35 and 55 years; and old, aged between 65 and 70 years individuals. Results: In terms of gender differences, in young-adult individuals the sex-related morphological differences observed, are just related to a significantly lower length of foot in females. In adult subjects morphological parameters investigated were significantly lower in females even after normalization for foot length. In old individuals, no differences of the parameters were found after normalization for foot length. Comparative analysis of morphometric data between young-adult and adult individuals revealed that the instep length was smaller in adults. The opposite was observed for the great toe and medial foot arch height. Length of ankle was higher in adult than in young-adult individuals, whereas ankle circumference and height were smaller. In old vs adult individuals foot circumference showed the most relevant age-related differences. Conclusions: Feet anatomy presents specific characteristics in different ages of life. The ideal footwear should take into account these characteristics. This is true primarily for the elderly for minimizing the risk of falls or of other problems related to inappropriate footwear. © 2014 Elsevier Ireland Ltd. All rights reserved.
1. Introduction The human feet are a complex structure each constituted by 26 bones, 33 joints, more than 100 muscles, tendons, ligaments, blood vessels, nerves, skin, and soft tissues. The above components, interacting together, create a flexible and articulated structure allowing the complex actions required for body support, movements and balance [1]. From a topographic anatomy point of view, foot is in general divided into three parts, namely forefoot, midfoot and hindfoot. The forefoot includes the five toes (phalanges) and the five longer bones (metatarsals). The midfoot represents a pyramid-like association of bones (cuneiform, cuboid and navicular bones) forming the arches of the feet. The hindfoot includes the heel (calcaneus)
∗ Corresponding author at: Scuola di Bioscienze e Medicina Veterinaria, Via Gentile III da Varano, 62032 Camerino (MC) Italy. Tel.: +39 0737-403320; fax: +39 0737 403325. E-mail addresses: [email protected] (D. Tomassoni), [email protected] (E. Traini), [email protected] (F. Amenta).
and the ankle. The heel bone is the largest bone of the foot, whereas the talus bone supports the leg bones (tibia and fibula), forming the ankle [1]. Feet are covered by footwear that may have a relevant role both in causing and in preventing foot and toe problems. A proper knowledge of foot anatomy represents the basis for the design and production of shoes. For instance, knowledge of the location of the metatarsophalangeal joint, is important for designing footwear with an appropriate grade of flexibility. Knowledge of ankle anatomy is important also from a medical point of view, being the ankle joint the site of many injuries affecting the lower limb. Hence, good basic anatomic information should be known by footwear designers that should consider properly foot shape and internal structure for developing “fit” and “healthy” shoes [2,3]. Several studies have investigated foot morphology as obviously footwear should be developed depending on foot shape. Possible gender differences in foot anatomy were one of the topic most investigated. [1,4,5]. Studies performed on different population groups (United States, Turkey, Native North and Central American) reported that
http://dx.doi.org/10.1016/j.maturitas.2014.07.019 0378-5122/© 2014 Elsevier Ireland Ltd. All rights reserved.
Please cite this article in press as: Tomassoni D, et al. Gender and age related differences in foot morphology. Maturitas (2014), http://dx.doi.org/10.1016/j.maturitas.2014.07.019
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men have longer feet than women for a given stature [6]. These finding are not consistent with data of other studies reporting no sex-specific differences in foot length [2] or larger values for the female population [2–5]. Foot morphology undergoes age-dependent changes and foot development and maturation is accompanied by variations in its shape and function. Younger people tend to have a smaller foot circumference compared with older people [7]. The elderly is reported to have flatter, longer, and wider feet than younger adults [8,9]. This explains the difficulty for older people to find, unless prepared specifically for them, fitting footwear, not too narrow or short for their feet [10–12]. The proportion of elderly people is increasing as well as the risk of falls with advanced aging [13,14]. Falls may have relevant consequences such as fractures, soft tissue injuries, functional impairment, and longstanding pain) [14–19]. This impairs quality of life and increases healthcare costs [20–25]. Risk factors for falls include intrinsic and extrinsic ones. The main intrinsic factors are impairment of the balance and of neuromuscular systems or other specific medical conditions [26–28]. Environmental factors comprising footwear represent the so-called extrinsic risk of falls [28–35]. Being footwear an easily modifiable falls risk factor, a better knowledge of age-related foot anatomy and the development of footwear taking into account changes advancing age induces in foot anatomy, may contribute to reduce the risk of falls. The present study has analyzed in a large population of individuals of different ages the main morphological parameters of foot to provide basic information for the development of appropriate footwear for the elderly.
2. Methods 2.1. Subjects The study was performed with the participation of 577 male and 528 female volunteers. Volunteers were all of the Caucasian race, born in Italy, from Italian parents. They were divided into three age groups, namely young-adult (aged between 20 and 25 years; n = 130 males and 128 females), adult (aged between 35 and 55 years; n = 283 males and 260 females) and old (aged between 65 and 70 years; n = 164 males and 140 females). Anthropometric evaluations in general classify people into at least four age-group classes such as infants, children, adolescents, adults and old people. Based on this classification our analysis included adult and old individuals. Recruitment of subjects for the present study was made grouping subjects according to the criteria of the US Anthropometric Reference Data [36]. Subjects of the young-adult group (20–25 years of age) and of the old people group (65–70 years of age) included the youngest and oldest group of individuals considered. For obtaining more homogeneous data in our inclusion we did consider only the first half of the 10-year groups reported by the US Anthropometric Reference Data [36]. The central age group (35–55 years) includes the estimated 25% of world population and was not subgrouped in our work as preliminary evaluations made on small groups of individuals aged within 5 years intervals did not reveal important inter age differences in the parameters evaluated. All participants met the following inclusion criteria: (1) no history of congenital deformity in the lower extremity or foot; (2) no previous history of lower extremity or foot fractures; (3) no surgical operation on foot and lower extremity; (4) no systemic diseases that could affect lower extremity or foot posture; (5) no history of trauma or pain to either foot, lower extremity
Fig. 1. Measurement of the foot length (A and B), instep length (C and D) and foot width (E and F). Left side panels photographs, right side panels schemes.
or lumbosacral region at least 12 months prior to start of the investigation. 2.2. Measurements This study was approved by the Joint Ethical Committee University of Camerino-Azienda ASUR 10 Marche, Camerino. After each participant completed a voluntary consent form, their height (stature) and weight were recorded by a weighing scale with height rod. Measurements of different foot parameters for the right and left foot independently, by the same investigator each subject, during morning (from 10 am to 01 pm), were taken using a millimetric table prepared for anthropometric measurements [37]. Before the study started, the technical error of the anthropometric variables by repeated measure on a small group of volunteers were evaluated; errors was from 0 to 0.1 mm for the length measures and from 0.2 to 0.3 for the circumference measurements, resulting acceptables [38]. The body was in a normal, upright position. The foot was placed on the measurement table so that the medial side would be touching the long side of the platform and the most prominent part of the heel would be touching the short side of it. The foot length (FL, Fig. 1, panels A and B) was measured between the extreme point of heel (foot end) and the extreme point of the longest toe (either first or second toe). The instep length (IL, Fig. 1, panels C and D) was measured as the distance between foot end (heel) and the fifth metatarso-phalangeal protrusion parallel to foot measuring line. The foot width (FW, Fig. 1, panels E and F) was
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Fig. 3. Measurement of the ankle length (A and B), ankle circumference (C and D) and ankle height (E and F).
the right and left foot were summed up and divided. Hence, values reported in the text refer to the mean value of right and left foot parameters under evaluation. Fig. 2. Measurement of the forefoot (ball) circumference (A and B), instep circumference (C and D), the medial foot arch height (E and F) and the great toe height (G and H).
taken as the distance between the inner side of the first metatarsal bone’s caput and the outer side of the fifth metatarsal bone’s caput. The forefoot (ball) circumference (FC, Fig. 2, panels A and B) was assessed at the level of metatarsal joint using a tape measure. The instep circumference (IC, Fig. 2, panels C and D) was considered as the measure of circumference passing through dorsal junction of the foot and leg. The distance between the floor and the higher point of the first toe was considered as the great toe height (GT, Fig. 2, panels E and F) while the distance between the floor and the highest point of the medial longitudinal arch of the foot was considered as the medial foot arch height (MH, Fig. 2, panels G and H). The distance between the medial dorsal junction of the foot and the hell of the foot was considered as the ankle length (AL, Fig. 3, panels A and B). Ankle circumference (AC, Fig. 3 panels C and D) was assessed by a tape-measure right above the medial and lateral malleoli. The ankle height (AH, Fig. 3, panels E and F) was considered as the distance between the heel of foot and the line right above the medial malleolus. Measurements of different morphometric parameters for each subject were recorded in millimeters and the values obtained from
2.3. Statistics Statistical analysis was done on all parameters before and after they are individually normalized for the length of the foot. Statistical significance of differences was evaluated by analysis of variance (ANOVA), followed by a two-tailed Student “t” test to evaluate the differences within the groups of different age. Significance was set at p < 0.05.
Table 1 Demographic characteristics of the population. Stature (cm)
BMI (kg/m2 )
Young-adults (20–25 years) 23 ± 1 Males 22 ± 1 Females
178 ± 7* 165 ± 6
21.4 ± 2.2 20.2 ± 2.3
Adults (35–55 years) Males 45 ± 8 44 ± 6 Females
175 ± 9 163 ± 10
23.2 ± 3.3 21.4 ± 2.4
Elders (65–70 years) Males 69 ± 2 67 ± 1 Females
173 ± 8 162 ± 7
23.7 ± 3.1 22.5 ± 2.2
Age (years)
BMI, body mass index. Data are the mean ± standard error. * Significative p < 0.05 vs female.
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Table 2 Foot morphometry in the young-adult group (age 20–25 years). Females n = 128
Males n = 130 Foot FL IL FW FC IC GT MH
261.7 177.1 101.7 242.1 257.7 18.37 22.61
Ankle AL AC AH
92.8 ± 13.8 244.2 ± 23.8 85.3 ± 11.0
± ± ± ± ± ± ±
13 15.8 6.3 17.4 13.6 2.34 3.32
233.7 157.0 91.2 217.2 226.2 17.09 18.89
± ± ± ± ± ± ±
Value normalized for foot length (males) 10.3* 12.6* 5.2* 11.5* 11.9* 2.29* 3.66*
0.68 0.39 0.93 0.98 0.07 0.09
82.5 ± 8.0* 210.7 ± 14.9* 77.1 ± 8.3*
± ± ± ± ± ±
Value normalized for foot length (females)
0.07 0.02 0.05 0.04 0.01 0.01
0.67 0.39 0.92 0.97 0.07 0.08
0.35 ± 0.04 0.93 ± 0.07 0.33 ± 0.04
± ± ± ± ± ±
0.04 0.01 0.05 0.06 0.01 0.02
0.35 ± 0.03 0.90 ± 0.06 0.33 ± 0.03
Data are express in millimeters (mm) and represent the mean ± S.D. of values obtained as indicated in Section 2. * p < 0.05 vs male group. FL, foot length; IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
3. Results
normalization of mean morphological values for foot length, statistical significance of differences was no longer observed (Table 4). The results of the comparative analysis of morphometric data, normalized by foot length, between young-adult and adult individuals are summarized in Table 5. As shown, both in male and female adults the instep length was smaller compared with young-adult individuals, whereas the opposite is for great toe height and medial foot arch height (Table 5). Length of ankle was higher in adult than in young-adult individuals, whereas ankle circumference and height were smaller (Table 5). In old vs adult individuals the foot circumference was the parameter showing the most relevant agerelated differences both in males and in females (Table 6), whereas other parameters assessed did not show other relevant dissimilarities except a slight reduction of medial foot arch (Table 6).
The main demographic characteristics of the population examined in this study are summarized in Table 1. Data of foot and ankle morphology in young-adult subjects are summarized in Table 2. The length of foot was significantly lower (−10.7%) in females compared to male individuals (Table 2). In individuals aged from 20 to 25 years the remaining six morphological of the foot and the three morphological parameters of the ankle investigated were significantly lower in females. Normalization of the different parameters for foot length resulted in the loss of inter-gender statistical significance (Table 2). Hence, except for the length of foot, no other sex-related morphological differences were noticeable in young-adult subjects (Table 2). In adult individuals, values of foot length were different between males and females (Table 3), and all other morphological parameters investigated were significantly lower in females (Table 3). Correction of the foot and ankle morphological parameters per foot length confirmed the statistical significance on inter-gender differences for all values except the medial foot height (Table 3). Hence, in the age range between 35 and 55 years female feet had a shorter foot compared to age-matched males. In old individuals, similarly as observed in the adult cohort, except than for the foot length, other parameters evaluated were significantly lower in females compared to males (Table 4). After
4. Discussion As mentioned in the introduction, knowledge of foot morphology may be useful in several areas ranging from pure anthropology to forensic medicine and footwear industry [39,40]. Foot morphological studies in the perspective of footwear design and production are probably those receiving more attention as knowledge of foot anthropometrics is a basic prerequisite for shoe design that should be based on foot shape [41–45]. The main scope of a shoe is to protect the foot and facilitate propulsion [46]. Unfortunately, influence
Table 3 Foot morphometry in the adult group (age 35–55 years). Females n = 260
Males n = 283 Foot FL IL FW FC IC GT MH
269.2 168.1 105.4 252.8 262.7 22.94 30.67
Ankle AL AC AH
108.9 ± 6.2 224.5 ± 6.0 127.2 ± 5.9
± ± ± ± ± ± ±
6.9 6.1 4.2 7.4 10.5 2.74 3.31
243.1 149.9 95.0 225.9 233.6 19.30 28.15
± ± ± ± ± ± ±
Value normalized for foot length (males) 3.9* 5.2* 3.7* 4.8* 5.2* 2.1* 3.4*
96.2 ± 4.4* 206.2 ± 19.9* 108.0 ± 6.2*
0.62 0.39 0.93 0.98 0.09 0.11
± ± ± ± ± ±
0.03 0.02 0.03 0.04 0.01 0.01
0.40 ± 0.02 0.83 ± 0.03 0.47 ± 0.02
Value normalized for foot length (females)
0.61 0.39 0.92 0.96 0.08 0.11
± ± ± ± ± ±
0.02* 0.01 0.02* 0.02* 0.01* 0.01
0.39 ± 0.01* 0.85 ± 0.08 0.44 ± 0.02*
Data are express in millimeters (mm) and represent the mean ± S.D. of values obtained as indicated in Section 2. * p < 0.05 vs male group. FL, foot length; IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
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Table 4 Foot morphometry in the old group (age 65–70 years). Males n = 164
Females n = 140
Value normalized for foot length (males)
Value normalized for foot length (females)
Foot FL IL FW FC IC GT MH
264.4 ± 11.6 163.9 ± 5.8 98.2 ± 4.42 256.4 ± 7.8 264.4 ± 11.6 23.81 ± 1.4 26.4 ± 3.17
247.4 ± 16.2* 148.7 ± 7.0* 94.1 ± 4.8* 235.4 ± 8.3* 240.4 ± 8.4* 22.35 ± 1.6* 22.3 ± 2.78*
0.62 ± 0.05 0.37 ± 0.02 0.97 ± 0.02 1.00 ± 0.06 0.09 ± 0.01 0.10 ± 0.01
0.60 ± 0.06 0.38 ± 0.03 0.96 ± 0.03 0.97 ± 0.08 0.09 ± 0.01 0.09 ± 0.02
Ankle AL AC AH
108.4 ± 5.9 224.7 ± 6.4 118.9 ± 4.6
99.1 ± 7.1* 213.1 ± 8.3* 109.1 ± 5.1*
0.41 ± 0.03 0.85 ± 0.06 0.45 ± 0.02
0.40 ± 0.02 0.86 ± 0.08 0.44 ± 0.03
Data are express in millimeters (mm) and represent the means ± S.D. of values obtained as indicated in Section 2. * p < 0.05 vs male group. FL, foot length; IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
Table 5 Comparison of foot morphometry values between young-adult and adult subjects. Young-adult males (age 20–25) Foot IL FW FC IC GT MH
0.68 0.39 0.93 0.98 0.07 0.09
Ankle AL AC AH
0.35 ± 0.04 0.93 ± 0.07 0.33 ± 0.04
± ± ± ± ± ±
0.07 0.02 0.05 0.04 0.01 0.01
Adult males (age 35–55) 0.62 0.39 0.94 0.98 0.09 0.11
± ± ± ± ± ±
0.03* 0.02 0.03 0.04 0.01* 0.01*
0.40 ± 0.02* 0.83 ± 0.03* 0.47 ± 0.02*
Young-adult females (age 20–25) 0.04 0.01 0.05 0.06 0.01 0.02
0.61 ± 0.02* 0.39 ± 0.01 0.93 ± 0.02 0.96 ± 0.02 0.08 ± 0.01* 0.11 ± 0.01*
0.35 ± 0.03 0.90 ± 0.06 0.33 ± 0.03
0.39 ± 0.01* 0.85 ± 0.08* 0.44 ± 0.02*
0.67 0.39 0.92 0.97 0.07 0.08
± ± ± ± ± ±
Adult females (age 35–55)
Data (mean ± S.D.) represent the comparative analysis of morphometric parameter evaluated normalized for foot length. * p < 0.05 vs young-adult group of the same gender. IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
Table 6 Comparison of foot morphometry values between adult and old subjects. Adult males (age 35–55) Foot IL FW FC IC GT MH
0.62 0.39 0.93 0.98 0.09 0.11
Ankle AL AC AH
0.40 ± 0.02 0.83 ± 0.03 0.47 ± 0.02
± ± ± ± ± ±
0.03 0.02 0.03 0.04 0.01 0.01
Old males (age 65–70) 0.62 0.37 0.97 1.00 0.09 0.10
± ± ± ± ± ±
0.05 0.02 0.02* 0.06 0.01 0.01*
0.41 ± 0.03 0.85 ± 0.06 0.45 ± 0.02
Adult females (age 35–55)
Old females (age 65–70)
0.61 ± 0.02 0.39 ± 0.01 0.92 ± 0.02 0.96 ± 0.02 0.08 ± 0.01 0.11 ± 0.01
0.60 0.38 0.96 0.97 0.09 0.09
0.39 ± 0.01 0.85 ± 0.08 0.44 ± 0.02
0.40 ± 0.02 0.86 ± 0.08 0.44 ± 0.03
± ± ± ± ± ±
0.06 0.03 0.03* 0.08 0.01 0.02*
Data (mean ± S.D.) represent the comparative analysis of morphometric parameter evaluated normalized for foot length. * p < 0.05 vs adult group of the same gender. IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
of fashion on footwear design throughout the ages has compromised the natural functioning of the foot. Several studies published on the topic have assessed gender differences in foot shape as well as variations related to age classes, races, and body type (for a review see [47]). In spite of many efforts, standardization of morphometric data for application to the footwear industry remains a complex task in view of differences in food shape from one subject to another one [45,47,48]. The idea of categorizing foot types into voluminous, flat-pointed and
slender [2] may facilitate definition of morphological differences across individuals, but the difficulties to systematize differences in foot anatomy still remain. Sex related-differences were the topic most extensively studied also recently. The former predominant idea was that male and female feet differ in terms of length, height, and width measures with larger values for the male population [2,49]. More recent investigations reported inconsistent results in values of foot or ballof-foot length between sexes [2,3]. At the present, the prevailing
Please cite this article in press as: Tomassoni D, et al. Gender and age related differences in foot morphology. Maturitas (2014), http://dx.doi.org/10.1016/j.maturitas.2014.07.019
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idea is that most of the reported gender differences are small in magnitude (
ARTICLE IN PRESS Maturitas xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Maturitas journal homepage: www.elsevier.com/locate/maturitas
Gender and age related differences in foot morphology Daniele Tomassoni a,∗ , Enea Traini b , Francesco Amenta b a
Scuola di Bioscienze e Medicina Veterinaria, Università di Camerino, 62032 Camerino, Italy Centro di Ricerche Cliniche, Telemedicina e Telefarmacia, Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, 62032 Camerino, Italy b
a r t i c l e
i n f o
Article history: Received 18 April 2014 Received in revised form 29 July 2014 Accepted 30 July 2014 Available online xxx Keywords: Foot anatomy Age-dependent changes Quantitative morphology Elderly Footwear
a b s t r a c t Objective: This study has assessed age-related changes of foot morphology for developing appropriate footwear with particular reference to the elderly. Methods: Anatomical parameters such as foot length, circumference and height and ankle length, circumference and height were assessed in a sample of males (n = 577) and females (n = 528) divided into three age groups. The groups included young-adult, aged between 20 and 25 years; adult, aged between 35 and 55 years; and old, aged between 65 and 70 years individuals. Results: In terms of gender differences, in young-adult individuals the sex-related morphological differences observed, are just related to a significantly lower length of foot in females. In adult subjects morphological parameters investigated were significantly lower in females even after normalization for foot length. In old individuals, no differences of the parameters were found after normalization for foot length. Comparative analysis of morphometric data between young-adult and adult individuals revealed that the instep length was smaller in adults. The opposite was observed for the great toe and medial foot arch height. Length of ankle was higher in adult than in young-adult individuals, whereas ankle circumference and height were smaller. In old vs adult individuals foot circumference showed the most relevant age-related differences. Conclusions: Feet anatomy presents specific characteristics in different ages of life. The ideal footwear should take into account these characteristics. This is true primarily for the elderly for minimizing the risk of falls or of other problems related to inappropriate footwear. © 2014 Elsevier Ireland Ltd. All rights reserved.
1. Introduction The human feet are a complex structure each constituted by 26 bones, 33 joints, more than 100 muscles, tendons, ligaments, blood vessels, nerves, skin, and soft tissues. The above components, interacting together, create a flexible and articulated structure allowing the complex actions required for body support, movements and balance [1]. From a topographic anatomy point of view, foot is in general divided into three parts, namely forefoot, midfoot and hindfoot. The forefoot includes the five toes (phalanges) and the five longer bones (metatarsals). The midfoot represents a pyramid-like association of bones (cuneiform, cuboid and navicular bones) forming the arches of the feet. The hindfoot includes the heel (calcaneus)
∗ Corresponding author at: Scuola di Bioscienze e Medicina Veterinaria, Via Gentile III da Varano, 62032 Camerino (MC) Italy. Tel.: +39 0737-403320; fax: +39 0737 403325. E-mail addresses: [email protected] (D. Tomassoni), [email protected] (E. Traini), [email protected] (F. Amenta).
and the ankle. The heel bone is the largest bone of the foot, whereas the talus bone supports the leg bones (tibia and fibula), forming the ankle [1]. Feet are covered by footwear that may have a relevant role both in causing and in preventing foot and toe problems. A proper knowledge of foot anatomy represents the basis for the design and production of shoes. For instance, knowledge of the location of the metatarsophalangeal joint, is important for designing footwear with an appropriate grade of flexibility. Knowledge of ankle anatomy is important also from a medical point of view, being the ankle joint the site of many injuries affecting the lower limb. Hence, good basic anatomic information should be known by footwear designers that should consider properly foot shape and internal structure for developing “fit” and “healthy” shoes [2,3]. Several studies have investigated foot morphology as obviously footwear should be developed depending on foot shape. Possible gender differences in foot anatomy were one of the topic most investigated. [1,4,5]. Studies performed on different population groups (United States, Turkey, Native North and Central American) reported that
http://dx.doi.org/10.1016/j.maturitas.2014.07.019 0378-5122/© 2014 Elsevier Ireland Ltd. All rights reserved.
Please cite this article in press as: Tomassoni D, et al. Gender and age related differences in foot morphology. Maturitas (2014), http://dx.doi.org/10.1016/j.maturitas.2014.07.019
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men have longer feet than women for a given stature [6]. These finding are not consistent with data of other studies reporting no sex-specific differences in foot length [2] or larger values for the female population [2–5]. Foot morphology undergoes age-dependent changes and foot development and maturation is accompanied by variations in its shape and function. Younger people tend to have a smaller foot circumference compared with older people [7]. The elderly is reported to have flatter, longer, and wider feet than younger adults [8,9]. This explains the difficulty for older people to find, unless prepared specifically for them, fitting footwear, not too narrow or short for their feet [10–12]. The proportion of elderly people is increasing as well as the risk of falls with advanced aging [13,14]. Falls may have relevant consequences such as fractures, soft tissue injuries, functional impairment, and longstanding pain) [14–19]. This impairs quality of life and increases healthcare costs [20–25]. Risk factors for falls include intrinsic and extrinsic ones. The main intrinsic factors are impairment of the balance and of neuromuscular systems or other specific medical conditions [26–28]. Environmental factors comprising footwear represent the so-called extrinsic risk of falls [28–35]. Being footwear an easily modifiable falls risk factor, a better knowledge of age-related foot anatomy and the development of footwear taking into account changes advancing age induces in foot anatomy, may contribute to reduce the risk of falls. The present study has analyzed in a large population of individuals of different ages the main morphological parameters of foot to provide basic information for the development of appropriate footwear for the elderly.
2. Methods 2.1. Subjects The study was performed with the participation of 577 male and 528 female volunteers. Volunteers were all of the Caucasian race, born in Italy, from Italian parents. They were divided into three age groups, namely young-adult (aged between 20 and 25 years; n = 130 males and 128 females), adult (aged between 35 and 55 years; n = 283 males and 260 females) and old (aged between 65 and 70 years; n = 164 males and 140 females). Anthropometric evaluations in general classify people into at least four age-group classes such as infants, children, adolescents, adults and old people. Based on this classification our analysis included adult and old individuals. Recruitment of subjects for the present study was made grouping subjects according to the criteria of the US Anthropometric Reference Data [36]. Subjects of the young-adult group (20–25 years of age) and of the old people group (65–70 years of age) included the youngest and oldest group of individuals considered. For obtaining more homogeneous data in our inclusion we did consider only the first half of the 10-year groups reported by the US Anthropometric Reference Data [36]. The central age group (35–55 years) includes the estimated 25% of world population and was not subgrouped in our work as preliminary evaluations made on small groups of individuals aged within 5 years intervals did not reveal important inter age differences in the parameters evaluated. All participants met the following inclusion criteria: (1) no history of congenital deformity in the lower extremity or foot; (2) no previous history of lower extremity or foot fractures; (3) no surgical operation on foot and lower extremity; (4) no systemic diseases that could affect lower extremity or foot posture; (5) no history of trauma or pain to either foot, lower extremity
Fig. 1. Measurement of the foot length (A and B), instep length (C and D) and foot width (E and F). Left side panels photographs, right side panels schemes.
or lumbosacral region at least 12 months prior to start of the investigation. 2.2. Measurements This study was approved by the Joint Ethical Committee University of Camerino-Azienda ASUR 10 Marche, Camerino. After each participant completed a voluntary consent form, their height (stature) and weight were recorded by a weighing scale with height rod. Measurements of different foot parameters for the right and left foot independently, by the same investigator each subject, during morning (from 10 am to 01 pm), were taken using a millimetric table prepared for anthropometric measurements [37]. Before the study started, the technical error of the anthropometric variables by repeated measure on a small group of volunteers were evaluated; errors was from 0 to 0.1 mm for the length measures and from 0.2 to 0.3 for the circumference measurements, resulting acceptables [38]. The body was in a normal, upright position. The foot was placed on the measurement table so that the medial side would be touching the long side of the platform and the most prominent part of the heel would be touching the short side of it. The foot length (FL, Fig. 1, panels A and B) was measured between the extreme point of heel (foot end) and the extreme point of the longest toe (either first or second toe). The instep length (IL, Fig. 1, panels C and D) was measured as the distance between foot end (heel) and the fifth metatarso-phalangeal protrusion parallel to foot measuring line. The foot width (FW, Fig. 1, panels E and F) was
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Fig. 3. Measurement of the ankle length (A and B), ankle circumference (C and D) and ankle height (E and F).
the right and left foot were summed up and divided. Hence, values reported in the text refer to the mean value of right and left foot parameters under evaluation. Fig. 2. Measurement of the forefoot (ball) circumference (A and B), instep circumference (C and D), the medial foot arch height (E and F) and the great toe height (G and H).
taken as the distance between the inner side of the first metatarsal bone’s caput and the outer side of the fifth metatarsal bone’s caput. The forefoot (ball) circumference (FC, Fig. 2, panels A and B) was assessed at the level of metatarsal joint using a tape measure. The instep circumference (IC, Fig. 2, panels C and D) was considered as the measure of circumference passing through dorsal junction of the foot and leg. The distance between the floor and the higher point of the first toe was considered as the great toe height (GT, Fig. 2, panels E and F) while the distance between the floor and the highest point of the medial longitudinal arch of the foot was considered as the medial foot arch height (MH, Fig. 2, panels G and H). The distance between the medial dorsal junction of the foot and the hell of the foot was considered as the ankle length (AL, Fig. 3, panels A and B). Ankle circumference (AC, Fig. 3 panels C and D) was assessed by a tape-measure right above the medial and lateral malleoli. The ankle height (AH, Fig. 3, panels E and F) was considered as the distance between the heel of foot and the line right above the medial malleolus. Measurements of different morphometric parameters for each subject were recorded in millimeters and the values obtained from
2.3. Statistics Statistical analysis was done on all parameters before and after they are individually normalized for the length of the foot. Statistical significance of differences was evaluated by analysis of variance (ANOVA), followed by a two-tailed Student “t” test to evaluate the differences within the groups of different age. Significance was set at p < 0.05.
Table 1 Demographic characteristics of the population. Stature (cm)
BMI (kg/m2 )
Young-adults (20–25 years) 23 ± 1 Males 22 ± 1 Females
178 ± 7* 165 ± 6
21.4 ± 2.2 20.2 ± 2.3
Adults (35–55 years) Males 45 ± 8 44 ± 6 Females
175 ± 9 163 ± 10
23.2 ± 3.3 21.4 ± 2.4
Elders (65–70 years) Males 69 ± 2 67 ± 1 Females
173 ± 8 162 ± 7
23.7 ± 3.1 22.5 ± 2.2
Age (years)
BMI, body mass index. Data are the mean ± standard error. * Significative p < 0.05 vs female.
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Table 2 Foot morphometry in the young-adult group (age 20–25 years). Females n = 128
Males n = 130 Foot FL IL FW FC IC GT MH
261.7 177.1 101.7 242.1 257.7 18.37 22.61
Ankle AL AC AH
92.8 ± 13.8 244.2 ± 23.8 85.3 ± 11.0
± ± ± ± ± ± ±
13 15.8 6.3 17.4 13.6 2.34 3.32
233.7 157.0 91.2 217.2 226.2 17.09 18.89
± ± ± ± ± ± ±
Value normalized for foot length (males) 10.3* 12.6* 5.2* 11.5* 11.9* 2.29* 3.66*
0.68 0.39 0.93 0.98 0.07 0.09
82.5 ± 8.0* 210.7 ± 14.9* 77.1 ± 8.3*
± ± ± ± ± ±
Value normalized for foot length (females)
0.07 0.02 0.05 0.04 0.01 0.01
0.67 0.39 0.92 0.97 0.07 0.08
0.35 ± 0.04 0.93 ± 0.07 0.33 ± 0.04
± ± ± ± ± ±
0.04 0.01 0.05 0.06 0.01 0.02
0.35 ± 0.03 0.90 ± 0.06 0.33 ± 0.03
Data are express in millimeters (mm) and represent the mean ± S.D. of values obtained as indicated in Section 2. * p < 0.05 vs male group. FL, foot length; IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
3. Results
normalization of mean morphological values for foot length, statistical significance of differences was no longer observed (Table 4). The results of the comparative analysis of morphometric data, normalized by foot length, between young-adult and adult individuals are summarized in Table 5. As shown, both in male and female adults the instep length was smaller compared with young-adult individuals, whereas the opposite is for great toe height and medial foot arch height (Table 5). Length of ankle was higher in adult than in young-adult individuals, whereas ankle circumference and height were smaller (Table 5). In old vs adult individuals the foot circumference was the parameter showing the most relevant agerelated differences both in males and in females (Table 6), whereas other parameters assessed did not show other relevant dissimilarities except a slight reduction of medial foot arch (Table 6).
The main demographic characteristics of the population examined in this study are summarized in Table 1. Data of foot and ankle morphology in young-adult subjects are summarized in Table 2. The length of foot was significantly lower (−10.7%) in females compared to male individuals (Table 2). In individuals aged from 20 to 25 years the remaining six morphological of the foot and the three morphological parameters of the ankle investigated were significantly lower in females. Normalization of the different parameters for foot length resulted in the loss of inter-gender statistical significance (Table 2). Hence, except for the length of foot, no other sex-related morphological differences were noticeable in young-adult subjects (Table 2). In adult individuals, values of foot length were different between males and females (Table 3), and all other morphological parameters investigated were significantly lower in females (Table 3). Correction of the foot and ankle morphological parameters per foot length confirmed the statistical significance on inter-gender differences for all values except the medial foot height (Table 3). Hence, in the age range between 35 and 55 years female feet had a shorter foot compared to age-matched males. In old individuals, similarly as observed in the adult cohort, except than for the foot length, other parameters evaluated were significantly lower in females compared to males (Table 4). After
4. Discussion As mentioned in the introduction, knowledge of foot morphology may be useful in several areas ranging from pure anthropology to forensic medicine and footwear industry [39,40]. Foot morphological studies in the perspective of footwear design and production are probably those receiving more attention as knowledge of foot anthropometrics is a basic prerequisite for shoe design that should be based on foot shape [41–45]. The main scope of a shoe is to protect the foot and facilitate propulsion [46]. Unfortunately, influence
Table 3 Foot morphometry in the adult group (age 35–55 years). Females n = 260
Males n = 283 Foot FL IL FW FC IC GT MH
269.2 168.1 105.4 252.8 262.7 22.94 30.67
Ankle AL AC AH
108.9 ± 6.2 224.5 ± 6.0 127.2 ± 5.9
± ± ± ± ± ± ±
6.9 6.1 4.2 7.4 10.5 2.74 3.31
243.1 149.9 95.0 225.9 233.6 19.30 28.15
± ± ± ± ± ± ±
Value normalized for foot length (males) 3.9* 5.2* 3.7* 4.8* 5.2* 2.1* 3.4*
96.2 ± 4.4* 206.2 ± 19.9* 108.0 ± 6.2*
0.62 0.39 0.93 0.98 0.09 0.11
± ± ± ± ± ±
0.03 0.02 0.03 0.04 0.01 0.01
0.40 ± 0.02 0.83 ± 0.03 0.47 ± 0.02
Value normalized for foot length (females)
0.61 0.39 0.92 0.96 0.08 0.11
± ± ± ± ± ±
0.02* 0.01 0.02* 0.02* 0.01* 0.01
0.39 ± 0.01* 0.85 ± 0.08 0.44 ± 0.02*
Data are express in millimeters (mm) and represent the mean ± S.D. of values obtained as indicated in Section 2. * p < 0.05 vs male group. FL, foot length; IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
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Table 4 Foot morphometry in the old group (age 65–70 years). Males n = 164
Females n = 140
Value normalized for foot length (males)
Value normalized for foot length (females)
Foot FL IL FW FC IC GT MH
264.4 ± 11.6 163.9 ± 5.8 98.2 ± 4.42 256.4 ± 7.8 264.4 ± 11.6 23.81 ± 1.4 26.4 ± 3.17
247.4 ± 16.2* 148.7 ± 7.0* 94.1 ± 4.8* 235.4 ± 8.3* 240.4 ± 8.4* 22.35 ± 1.6* 22.3 ± 2.78*
0.62 ± 0.05 0.37 ± 0.02 0.97 ± 0.02 1.00 ± 0.06 0.09 ± 0.01 0.10 ± 0.01
0.60 ± 0.06 0.38 ± 0.03 0.96 ± 0.03 0.97 ± 0.08 0.09 ± 0.01 0.09 ± 0.02
Ankle AL AC AH
108.4 ± 5.9 224.7 ± 6.4 118.9 ± 4.6
99.1 ± 7.1* 213.1 ± 8.3* 109.1 ± 5.1*
0.41 ± 0.03 0.85 ± 0.06 0.45 ± 0.02
0.40 ± 0.02 0.86 ± 0.08 0.44 ± 0.03
Data are express in millimeters (mm) and represent the means ± S.D. of values obtained as indicated in Section 2. * p < 0.05 vs male group. FL, foot length; IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
Table 5 Comparison of foot morphometry values between young-adult and adult subjects. Young-adult males (age 20–25) Foot IL FW FC IC GT MH
0.68 0.39 0.93 0.98 0.07 0.09
Ankle AL AC AH
0.35 ± 0.04 0.93 ± 0.07 0.33 ± 0.04
± ± ± ± ± ±
0.07 0.02 0.05 0.04 0.01 0.01
Adult males (age 35–55) 0.62 0.39 0.94 0.98 0.09 0.11
± ± ± ± ± ±
0.03* 0.02 0.03 0.04 0.01* 0.01*
0.40 ± 0.02* 0.83 ± 0.03* 0.47 ± 0.02*
Young-adult females (age 20–25) 0.04 0.01 0.05 0.06 0.01 0.02
0.61 ± 0.02* 0.39 ± 0.01 0.93 ± 0.02 0.96 ± 0.02 0.08 ± 0.01* 0.11 ± 0.01*
0.35 ± 0.03 0.90 ± 0.06 0.33 ± 0.03
0.39 ± 0.01* 0.85 ± 0.08* 0.44 ± 0.02*
0.67 0.39 0.92 0.97 0.07 0.08
± ± ± ± ± ±
Adult females (age 35–55)
Data (mean ± S.D.) represent the comparative analysis of morphometric parameter evaluated normalized for foot length. * p < 0.05 vs young-adult group of the same gender. IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
Table 6 Comparison of foot morphometry values between adult and old subjects. Adult males (age 35–55) Foot IL FW FC IC GT MH
0.62 0.39 0.93 0.98 0.09 0.11
Ankle AL AC AH
0.40 ± 0.02 0.83 ± 0.03 0.47 ± 0.02
± ± ± ± ± ±
0.03 0.02 0.03 0.04 0.01 0.01
Old males (age 65–70) 0.62 0.37 0.97 1.00 0.09 0.10
± ± ± ± ± ±
0.05 0.02 0.02* 0.06 0.01 0.01*
0.41 ± 0.03 0.85 ± 0.06 0.45 ± 0.02
Adult females (age 35–55)
Old females (age 65–70)
0.61 ± 0.02 0.39 ± 0.01 0.92 ± 0.02 0.96 ± 0.02 0.08 ± 0.01 0.11 ± 0.01
0.60 0.38 0.96 0.97 0.09 0.09
0.39 ± 0.01 0.85 ± 0.08 0.44 ± 0.02
0.40 ± 0.02 0.86 ± 0.08 0.44 ± 0.03
± ± ± ± ± ±
0.06 0.03 0.03* 0.08 0.01 0.02*
Data (mean ± S.D.) represent the comparative analysis of morphometric parameter evaluated normalized for foot length. * p < 0.05 vs adult group of the same gender. IL, instep length; FW, foot width; FC, forefoot circumference; IC, instep circumference; GT, great toe height; MH, medial foot arch height; AL, ankle length; AC, ankle circumference; AH, ankle height.
of fashion on footwear design throughout the ages has compromised the natural functioning of the foot. Several studies published on the topic have assessed gender differences in foot shape as well as variations related to age classes, races, and body type (for a review see [47]). In spite of many efforts, standardization of morphometric data for application to the footwear industry remains a complex task in view of differences in food shape from one subject to another one [45,47,48]. The idea of categorizing foot types into voluminous, flat-pointed and
slender [2] may facilitate definition of morphological differences across individuals, but the difficulties to systematize differences in foot anatomy still remain. Sex related-differences were the topic most extensively studied also recently. The former predominant idea was that male and female feet differ in terms of length, height, and width measures with larger values for the male population [2,49]. More recent investigations reported inconsistent results in values of foot or ballof-foot length between sexes [2,3]. At the present, the prevailing
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idea is that most of the reported gender differences are small in magnitude (
