Growth of the foot in early infants.

1991 Fiscal Year Final Research Report Summary

• Project/Area Number: 02640635
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 人類学(含生理人類学)
• Research Institution: University of Tsukukuba
• Principal Investigator: OKADA Morihiko Univ. of Tsukuba Prof., 体育科学系, 教授 (60011615)
• Co-Investigator(Kenkyū-buntansha): SHINDO Masao Univ. of Tsukuba Assoc. Prof., 体育科学系, 助教授 (10015886) ; KOUCHI Makiko Prod. Res. Inst. Senior Res., 製品科学研究所, 主任研究官 (80126052) ; TAKAI Shozo Univ. of Tsukuba Assoc. Prof., 体育科学系, 助教授 (20050643)
• Project Period (FY): 1990 – 1991
• Keywords: Foot / Morphology / Growth / Infant / Posture / Locomotion

Research Abstract

For 449 infants aged from 4 months to 36 months, the information on birth date, sex, body height(recumbent length), body weight, and locomotor development(whether they had started crawling, standing, or walking)was obtained, and pictures of both feet were taken by pedscope. From these pictures, 5 length and 2 breadth measurements of the foot were taken, and 5 indices were calculated. Growth changes in these measurements, indices, and the shape of foot outline analyzed by skeleton method were investigated, and the following results were obtained :
(1)Foot size
i. In body height(recumbent length)and weight, rapid growth continues until 7 months of age, and in foot length until 12 months.
ii. Male infants are larger than female infants from 4 to 18 months, but no significant sex difference is observed after 18 months.
iii. Foot breadth approaches the size at 36 months earliest, followed by length measurements of the foot, height(recumbent length), and weight in this order.
(2)Foot proportion
i. Relative foot length increases until 12 months, and retains constant after that age.
ii. Proportions between length measurements do not show changes with age.
iii. The ball of foot becomes relatively narrower with age, whereas the heel becomes relatively wider until 18, months, and then becomes relatively narrower again.
(3)Foot shape
i. Foot pronation appears at 7 to 12 months, and little change is observed in this characteristics after that age.
ii. Adduction of anterior part of the foot increase with age.
(4)Relation with locomotor development
i. Those who have started standing and walking have relatively and absolutely larger feet than those who have not, while there are no difference in body size.
ii. No correlation is observed between foot proportion and locomotor development.
iii. Adduction of the anterior part of the foot increases with the start of standing, but no correlation is observed between the foot outline shape and the start of walking.