THE INFLUENCE OF PREVALENCE A SURVEY UDAYA From We analysed influence static of footwear BHASKARA Kasturba of 2300 footprints FLAT 2300 CHILDREN RAO, Medical JOSEPH Manipal, between children FOOT BENJAMIN College, THE India the ages of four and 13 years to establish the who used footwear was 8.6% compared with 2.8% in those who did not between the predominance in shod and unshed children were noted in all with generalised ligament laxity. Flat foot was most common in children who wore closed-toe shoes, less common in those who wore sandals or slippers, and least in the unshod. Our findings suggest that shoe-wearing in early childhood is detrimental to the development of a normal longitudinal arch. (p 0.001). age groups, In Europe and 1979), America flat foot at a children’s but treatment in India this complaint all wear shoes. child from the children The farming who If the incidence reason clinic are brought few children who community or from complained of flat the these for do attend family do radius of of 10 km and and were two located all the children English-speakin an area were from with a a common background. School attendance in the region is good and all the children at school on the day of the screening were included in the study (Table I). Static footprints of both feet were obtained from all 2300 generally children the rural not (vernacular) All six schools ethnic foot. children Kannada-speaking ing schools. families and never seen a of flat foot is so low among is it because for (Sharrard seldom are from affluent urban In our clinic we have labourer population, is a common orthopaedic for flat foot. with they a manual children Significant differences most marked in those < attendance among OF ON of flat foot. on the prevalence The incidence OF FOOTWEAR wear using Harris and and Marshall differential Chacko of shoes 1984; Joseph also influence et al 1987). the development ofthe mediallongitudinal arch? Our aims were to establish the prevalence offlat foot in a population of schoolchildren in rural India and to determine whether this prevalence varied between shod and unshod of Our survey included girls) between the should AND in Orthopaedics Orth, Consultant II Surgery, India. be sent © No. 4, JULY 1992 Orthopaedic used footwear; schools did not Kasturba and Joint 1063 four Surgeon Medical to Dr B. Joseph. 1992 British Editorial Society of Bone 0301 -620X/92/4421 $2.00 J Bone Joint Surg [Br] 1992 ; 74-B :525-7. 74-B. schools in Kannada-speaking high- METHODS 2300 children (1237 boys and ages of four and 1 3 years from U. B. Rao, MB BS, Resident B. Joseph, MS Orth, MCh Head ofOrthopaedic Unit Department of Orthopaedic Manipal 576 1 19, Karnataka, VOL. English-speaking normal, children. MATERIAL Correspondence in the 50.7% of children use footwear. as mat Welton children and classified Rose, (Joseph, Jacob were footprint by arched or flat (Fig. 1). Some form of footwear was worn by I 555 children while 745 never used shoes. All the the wearing footprints pressure as described shoes? The use of footwear is known to increase the risk of hallux valgus (Sim-Fook and Hodgson 1958; Shine 1965) and to decrease the incidence of hallux varus Does The the Beath (1947) (1985). Surgery and College, Fig. 1 Method ofgrading footprints. If the width of the instep (AB) at its widest part was less than 1 cm the foot was considered as flat (right). If the width of the footprint at its narrowest part (BC) was less than 1 cm, the arch was considered high (centre). All other footprints were considered normal (left). 525 526 U. B. RAO, Table I. The number of children in each B. JOSEPH of the six schools and Footwear Children Table Total strength Number Percent Kannada/Parkala 543 501 92.3 Kannada/Kadiyali 542 536 98.9 Kannada/Manipal 252 216 85.7 Kannada/Saralabettu 210 197 English/Indrali 263 English/Manipal 630 The prevalence high-arched foot offlat Closed-toe shoes None 1.6 14.2 21.3 62.9 3.5 35.4 19.1 42.0 4.2 21.7 21.3 52.8 93.8 2.0 22.4 34.5 41.1 254 96.6 32.8 34.0 33.2 0 596 94.6 37.7 13.0 49.3 0 Table III. The distribution different forms of footwear foot in each group is shown foot at different Sandals Slippers UnshOd Total 6 14.3 Normal 243 335 508 462 1548 7 9.1 17.6 High-arched 53 147 130 262 592 8 7.9 26.5 Flat 45 (13.2) 9 5.3 25.5 Total 10 3.8 28.3 foot 11 3.3 31.4 12 2.2 36.9 13 2.5 40.5 #{149}six children oftwo child elbows, or morejoints on a scale measured by Index (BMI) was the weight (kg) by with a BMI of (Bray, Jordan for features fingers, 710 children. ligament laxity who had The (± 2.05 ( ± 2.0 bilaterally and or both feet foot. The decreased with was taken The years very 1953). studied, 1 55 1 were in both feet, 595 had and 154 (6.7%) had unilateral prevalence of flat foot increasing age (Table 695 as they wore considered a high arch to in or bilateral progressively II) ; it was 154 745 different types 2294 of footwear The was SD). four were rigid and laxity was detected ratio of flat foot in 14.4% compared with no ligament mean BMI SD) foot, only Ligament flat foot in children is shown in Table III. laxity. for children and for those This difference with had in children with 3.3% in those flat foot without flat foot is not statistically was 14.72 it was 14.61 significant. DISCUSSION RESULTS children arches flat test. ankles. overall Morley’s The flat (Jack included of ligamentous knees test were not 21 (2.8) the year comparable which 513 Of those with a negative Jack’s (m). Individuals to be overweight each were 57 (8.2) (p < 0.001). The frequency of wearing various types of footwear of each child was measured of 100 g ; their height was thumbs, 31 (6.0) 341 to indicate generalised ligament laxity. Genu valgum, femoral and tibial torsional abnormalities and shortness ofthe calcaneal tendon were noted. We performed Jack’s one flat wearing of flat 14.9 Sims 1976). We examined Of the 2300 have normal children percentage Closed-toe shoes the square of the height over 24 were considered on all feet types among children. The Footprint a stadiometer. The Body Mass calculated for each child by dividing Hypermobility of footprint and unshod in parentheses High-arched feet (per cent) The weight an accuracy of the (percentage) Slippers during laxity sc reened Flat foot (per cent) Age (yr) and of children habits Sandals ages with shoe-wearing sereened Language/ location ofschool II. and their 12.1% among children attending English-speaking schools and 3.5% in those at Kannada-speaking schools (p < 0.001). There was a significantly higher prevalence in children who wore shoes (8.6%) than among the unshod (2.8%) prevalence with of that reported of age, however, low, while in the value. distinctly higher flat foot in by Morley among unshod shod children incidence this study was At ten (1957). children it was it was as high as in children who used footwear suggests that shoe-wearing predisposes to flat foot. Before accepting a causal relationship, however, some confounding variables should be excluded. Among factors known to be associated with flat foot are ligament laxity and obesity (Sharrard 1979). It has also been established that there is a tendency for the arch to improve spontaneously with age (Morley 1957) as was also shown in our study (Table II). A higher proportion of younger children or children with ligamentous laxity among for the those who wore shoes, however, did not account high incidence of flat foot in them since the trend THE JOURNAL OF BONE AND JOINT SURGERY THE INFLUENCE Table IV. in various Percentage age groups of normal, Number unshod Shod Unshod Shod UnshOd Shod UnshOd p-value 97 70.1 72.1 12.6 18.6 17.3 9.2 NS 61.0 17.0 34.5 10.1 4.5 0.001 9to 506 242 70.2 65.2 23.3 34.3 6.5 0.4 0.001 353 229 66.0 55.0 30.3 43.7 3.7 1.3 0.001 10 II Percentage ligament of normal, laxity < high-arched Number shod 6 8 10 I1 <6 8 of the groups between the This analysed, prevalence suggests Number unshod 127 182 132 65 50 65 52 37 104 47 1 12 190 192 283 374 288 and was independent laxity (Table in the study. flat any factor It seems that closed-toe of the arch of the foot This may be because children. These observations Our in early normal ibility VOL. that begun cross-sectional study childhood is detrimental 74-B, No. 4, JULY 1992 without Unshod Shod Unshod p-value 65.4 76.0 14.2 12.0 20.5 12.0 67.0 56.9 13.2 33.8 19.8 9.2 64.4 58.5 78.8 54.1 21.2 29.2 21.2 43.2 14.4 12.3 0 2.7 NS 0.001 0.05 NS 76.0 68.1 10.6 25.5 13.5 6.4 76.7 72.2 67.7 63.4 61.6 55.2 19.4 24.1 30.6 34.8 37.9 43.8 3.9 3.7 1.7 evident if there is associated most V). ligament laxity. be encouraged sandals are less We to play harmful The authors thank Dr R. S. Phaneendra Rao and Dr T. N. Sugathan of the Department of Community Medicine, Kasturba Medical College, for their assistance, Mr T. S. Krishna Rao and Mrs Y. Shreemathi for the statistical analysis, and Dr S. Solomon of SLRTC, Karigiri, for providing the Harris and Beath mat. No benefits the 0.05 0.01 0.001 0.05 1.8 0.5 1.0 suggest that children should unshod and that slippers and than closed-toe shoes. from this in any form a commercial party have related been received directly or will be received or indirectly to the subject of article. muscle contrary to the earlier. suggests that shoe-wearing to the development of a or a high medial longitudinal for flat foot among children and Shod the arch is before six years. This hypothesis is supported by the observations of Rose et al (1985) who noted that ‘treatment’ for flat foot instituted after the age of four is than with Unshod statement of Kelsey (1982) that there is no evidence that the type offootwear influences the occurrence offlat foot. The high concentration of flat foot among six-yearold children who wore shoes as compared with those who did not, implies that the critical age for development of less effective children shoes inhibit more than do intrinsic are unshod Shod who wear slippers and sandals as they are more removed than shoes. Such interludes of unshod may account for the lower prevalance of flat foot in these and Unilateral/ bilateral flat foot detri- who used footwear. foot also varied with shod Unilateral/ bilateral high arch development of a normal arch leads to a of high-arched feet and a high one of in children of flat among feet we noted an inverse of flat foot and of that feet Normal activity is necessary to keep slippers from falling off. Rural Indian children who normally use footwear, tend to play barefoot, and this is more common among children easily activity children Unilateral/ bilateral fla t foot was seen in all age groups (Table IV)and of the presence or absence of ligament In addition, there were no obese children or sandals. unshod Unilateral/ bilateral hi gh arch 9 to 10 >11 slippers and 72.9 7 to type of footwear. the development shod 527 177 ligaments as was seen preponderance among FOOT 465 > foot, The feet FLAT 7 to 8 9to flat flat OF 231 7 to mental to the low proportion and PREVALENCE <6 Lax ligaments feet. high-arched THE Norm al feet Age (yr) high-arched ON Number shod Table V. generalised In each relationship FOOTWEAR Age (yr) > Normal OF arch. The who wear susceptshoes is REFERENCES GA, Jordan Bray algorithm. HA, in Canadian Canada, 1947. Jack EA. Evaluation of the obese patient. 1. An 1976; 235:1487-91. JAMA RI, Beath T. Army Harris EA. Sims foot survey soldiers. 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