title: Gait Transitions in Human Infants: Coping with Extremes of Treadmill Speed.
abstract: Spinal pattern generators in quadrupedal animals can coordinate different forms of locomotion, like trotting or galloping, by altering coordination between the limbs (interlimb coordination). In the human system, infants have been used to study the subcortical control of gait, since the cerebral cortex and corticospinal tract are immature early in life. Like other animals, human infants can modify interlimb coordination to jump or step. Do human infants possess functional neuronal circuitry necessary to modify coordination within a limb (intralimb coordination) in order to generate distinct forms of alternating bipedal gait, such as walking and running? We monitored twenty-eight infants (7-12 months) stepping on a treadmill at speeds ranging between 0.06-2.36 m/s, and seventeen adults (22-47 years) walking or running at speeds spanning the walk-to-run transition. Six of the adults were tested with body weight support to mimic the conditions of infant stepping. We found that infants could accommodate a wide range of speeds by altering stride length and frequency, similar to adults. Moreover, as the treadmill speed increased, we observed periods of flight during which neither foot was in ground contact in infants and in adults. However, while adults modified other aspects of intralimb coordination and the mechanics of progression to transition to a running gait, infants did not make comparable changes. The lack of evidence for distinct walking and running patterns in infants suggests that the expression of different functional, alternating gait patterns in humans may require neuromuscular maturation and a period of learning post-independent walking.
authors.affiliation: Rehabilitation Research and Movement Performance (RRAMP) Lab, Health and Rehabilitation Sciences, School of Health Technology and Management, Stony Brook University, Stony Brook, New York, United States of America.
authors.forename: Erin V
authors.initials: EV
authors.lastname: Vasudevan
authors.affiliation: Department of Physical Therapy, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Susan K
authors.initials: SK
authors.lastname: Patrick
authors.affiliation: Department of Physical Therapy, University of Alberta, Edmonton, Alberta, Canada.|Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jaynie F
authors.initials: JF
authors.lastname: Yang
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001835:Body Weight; D005080:Exercise Test; D005684:Gait / Q000502:physiology*; D006801:Humans; D007223:Infant; D008875:Middle Aged; D012420:Running / Q000502:physiology; D016138:Walking / Q000502:physiology; D055815:Young Adult
references.citation: J Physiol. 2003 Nov 15;553(Pt 1):319-31
references.pmid: 12963805
references.citation: Dev Psychobiol. 1970;3(4):267-80
references.pmid: 5527425
references.citation: J Neurophysiol. 2003 Oct;90(4):2731-40
references.pmid: 12826655
references.citation: J Neurosci. 2005 Jul 20;25(29):6869-76
references.pmid: 16033896
references.citation: J Neurophysiol. 2011 May;105(5):2195-203
references.pmid: 21368001
references.citation: Brain Res Dev Brain Res. 1998 Jun 15;108(1-2):111-23
references.pmid: 9693789
references.citation: J Exp Psychol Hum Percept Perform. 1987 Aug;13(3):405-10
references.pmid: 2958589
references.citation: Brain Res. 1979 Apr 6;165(1):177-82
references.pmid: 427583
references.citation: J Appl Physiol. 1963 Mar;18:367-70
references.pmid: 13932993
references.citation: J Mot Behav. 1983 Jun;15(2):99-137
references.pmid: 15151875
references.citation: Brain Res. 1982 Aug 12;245(2):353-64
references.pmid: 7127076
references.citation: Arch Dis Child. 2005 Aug;90(8):807-12
references.pmid: 15863466
references.citation: J Neurosci. 2007 Aug 8;27(32):8558-62
references.pmid: 17687033
references.citation: Dev Psychobiol. 1983 Jan;16(1):29-46
references.pmid: 6825965
references.citation: J Biomech. 2006;39(3):444-52
references.pmid: 16389084
references.citation: PLoS One. 2015;10(3):e0121951
references.pmid: 25775426
references.citation: Front Physiol. 2012 May 01;3:112
references.pmid: 22557975
references.citation: Acta Physiol Scand. 1985 Apr;123(4):457-75
references.pmid: 3993402
references.citation: Birth Defects Orig Artic Ser. 1983;19(4):357-73
references.pmid: 6871404
references.citation: Annu Rev Physiol. 2000;62:723-53
references.pmid: 10845109
references.citation: Exerc Sport Sci Rev. 1998;26:253-85
references.pmid: 9696992
references.citation: J Exp Biol. 2013 Aug 15;216(Pt 16):3047-54
references.pmid: 23619411
references.citation: Dev Psychobiol. 2015 May;57(4):397-408
references.pmid: 25754858
references.citation: J Appl Physiol (1985). 2011 Mar;110(3):781-8
references.pmid: 21212248
references.citation: Exp Brain Res. 1979 Jan 15;34(2):241-61
references.pmid: 421750
references.citation: J Neurophysiol. 2011 Sep;106(3):1525-36
references.pmid: 21697441
references.citation: Acta Physiol Scand. 1994 Mar;150(3):315-23
references.pmid: 8010138
references.citation: Brain Res Dev Brain Res. 1991 Feb 22;58(2):251-5
references.pmid: 2029768
references.citation: Physiol Rev. 1989 Oct;69(4):1199-227
references.pmid: 2678167
references.citation: Proc Biol Sci. 2011 Jul 7;278(1714):2040-6
references.pmid: 21123267
references.citation: Child Dev. 1995 Oct;66(5):1541-53
references.pmid: 7555229
references.citation: J Appl Physiol. 1964 Mar;19:249-56
references.pmid: 14155290
references.citation: Exp Brain Res. 1985;57(3):480-93
references.pmid: 3979491
references.citation: J Physiol. 2001 Jun 1;533(Pt 2):617-25
references.pmid: 11389217
references.citation: Acta Physiol Scand. 1980 Mar;108(3):269-81
references.pmid: 7376922
references.citation: J Neurophysiol. 2000 May;83(5):2814-24
references.pmid: 10805679
references.citation: J Neurophysiol. 2005 Aug;94(2):1057-65
references.pmid: 15800075
references.citation: Eur J Appl Physiol. 2003 Jan;88(4-5):297-316
references.pmid: 12527959
references.citation: J Bone Joint Surg Am. 1980 Apr;62(3):336-53
references.pmid: 7364807
references.citation: J Exp Biol. 2007 Feb;210(Pt 4):578-85
references.pmid: 17267643
references.citation: Acta Neurobiol Exp (Wars). 1996;56(1):449-63
references.pmid: 8787206
references.citation: Acta Physiol Scand Suppl. 1983;521:1-75
references.pmid: 6582764
references.citation: J Physiol. 1998 Mar 15;507 ( Pt 3):927-37
references.pmid: 9508851
references.citation: J Physiol. 1976 Nov;262(3):639-57
references.pmid: 1011078
references.citation: Brain. 2004 Oct;127(Pt 10):2232-46
references.pmid: 15289272
references.citation: Proc Natl Acad Sci U S A. 2012 Oct 9;109(41):16480-5
references.pmid: 23012402
references.citation: J Appl Physiol. 1963 Jan;18:1-9
references.pmid: 14019429
references.citation: J Neurophysiol. 2007 Feb;97(2):1247-57
references.pmid: 17151226
references.citation: Gait Posture. 2006 Oct;24(2):247-54
references.pmid: 16314100
references.citation: Acta Astronaut. 2001 Aug-Nov;49(3-10):191-8
references.pmid: 11669109
references.citation: Gait Posture. 2010 Jan;31(1):52-6
references.pmid: 19796948
references.citation: Dev Psychobiol. 1979 Mar;12(2):101-27
references.pmid: 456750
references.citation: Brain Res. 1977 Aug 19;132(1):121-39
references.pmid: 890471
references.citation: J Physiol. 1996 Jun 1;493 ( Pt 2):589-601
references.pmid: 8782119
references.citation: J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2005 Mar;191(3):213-29
references.pmid: 15452660
references.citation: Eur J Appl Physiol Occup Physiol. 1994;68(4):285-90
references.pmid: 8055884
references.citation: J Neurophysiol. 2008 Oct;100(4):2225-34
references.pmid: 18650307
references.citation: J Exp Biol. 2015 Oct;218(Pt 20):3192-8
references.pmid: 26276863
references.citation: Acta Physiol Scand. 1987 Oct;131(2):211-4
references.pmid: 3673618
references.citation: Acta Physiol Scand. 1980 Mar;108(3):283-95
references.pmid: 7376923
references.citation: Science. 1986 Feb 21;231(4740):840-3
references.pmid: 3945811
references.citation: Brain. 2000 Jan;123 ( Pt 1):51-64
references.pmid: 10611120
references.citation: Anim Behav. 1975 Nov;23(4):896-920
references.pmid: 1200422
references.citation: J Neurophysiol. 2002 Dec;88(6):3108-17
references.pmid: 12466434
references.citation: Can J Physiol Pharmacol. 2004 Aug-Sep;82(8-9):662-74
references.pmid: 15523523
references.citation: Early Hum Dev. 1994 Oct 28;39(2):109-26
references.pmid: 7533076