Electromyographic Study on Primitive Walking in Neonates and Infants

Research Project

Project/Area Number	61580123
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	体育学
Research Institution	Kansai Medical University
Principal Investigator	OKAMOTO Tsutomu Kansai Medical University, 医学部, 教授 (50077624)
Co-Investigator(Kenkyū-buntansha)	GOTO Yukihiro Htogo University of Teacher Education, 学校教育, 助教授 (00047391)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥1,900,000 (Direct Cost: ¥1,900,000) Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000) Fiscal Year 1986: ¥1,500,000 (Direct Cost: ¥1,500,000)
Keywords	EMG / Primitive Walking / Neonate / 歩行 / 筋電図
Research Abstract	Up to the second or third month of life,if a beby is held upright by the trunk so that the feet reach a flat table,the baby will take steps as if walking.We call this"primitive walking".At the 6th congress of ISEK (International Society of Electrophysiological Kinesiology)in Tokyo(1985), we reported on some differeces in muscle activity between neonates and infants. We have examined this problem more carefully to see if elements of and adult pattern could be found in primitive walking.We looked at six babies,recording EMGs from two or three weeks of age to about six months.Up to the first month of age,the tibialis anterior(TA)was active just before floor contact, but not the lateral gastrocnemius(LG).This is basically like adult human walking.From the first to the second month of life,we saw more activity in the vastus medialis(VM)and the LG just before floor contact,suggesting that knee and ankle plantarflexion were performed more actively.At this time we could see more often actively of the LG before floor contact,which was like quadrupedal walking.At around three months of age,strong activity from the LG just before floor contact became more definite and we usually saw digitigrade contact.We interpret TA activity before floor contact to suggest a bipedal mechanism present within the first month of life.So we believe that man already possesses a bipedal motor program at the time of birth.