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Creeping patterns of human adults and infants.

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AMERICAN JOURNAL O F PHYSICAL ANTHROPOLOGY 78:387-401(1989)
Creeping Patterns of Human Adults and Infants
W.A. SPARROW
Faculty of Special Education and Paramedical Studies, Victoria College,
Burwood, Victoria 3125, Australia
KEY WORDS
Gait, Ontogeny, Phylogeny
ABSTRACT
The patterns of swing and support €or the hands-and-feet or
hands-and-knees gaits (creeping) of human adults and infants are compared
based on data from a number of studies. Human infants show considerable
variability in their creeping gait patterns, whereas adult patterns are less
variable and fairly consistent after a few minutes of practice. Creeping on
hands-and-knees appears to dictate a gait pattern characteristically different
from creeping on hands-and-feet. The highly inefficient nature of adult creeping supports the view that our early hominid ancestors were poorly adapted to
quadrupedal locomotion. Data obtained from high-speed film analysis of human creeping patterns show that the number of foot lengths per stride in
creeping is about twice that for normal upright walking at the same speed.
The support pattern of human creeping is different from that of nonhuman
primates. These findings are discussed in the context of debate concerning the
origin of the Laetoli hominid footprints and the knuckle-walking hypothesis.
The biomechanics of humans upright walking have been documented extensively with
respect to the kinematics (Grieve and Gear,
1966; Rosenrot et aL, 1980; Shapiro et
a1.,1981; Winter, 1984; Vilensky and Gehlsen, 19841, kinetics (Cappozo et al., 1976;
Pierrynowski et al., 19811,andenergetics(B0bbert, 1960; Cavagna, 1973; Cavagna and Kaneko, 1977; Cotes and Meade, 1960; Dean,
1965; Donovan and Brooks, 1977; Margaria,
1976;Ralston, 1976)of both normal andpathological gaits. This paper is designed to examine creeping patterns in human adults
and infants. Following Burnside (19271,
creeping is defined here as the mode of progression whereby one “walks” on hands and
feet (or knees), with no other body parts in
contact with the supporting surface. Crawling will not be described in this paper, but
should be defined because the terms creeping
and crawling are sometimes used interchangably. In agreement with Ames’ (1937),
acceptance of Burnside’s (1927) definition of
crawling is recommended; “In crawling, the
abdomen is in contact with the supporting
surface, while the body is pulled along by the
arms only, nearly simultaneously, with the
legs dragging” (p. 338).
‘c) 1989 ALAN
R. 1,ISS. TNC
Sparrow and Zrizarry-Lopez (1987) examined the locomotor pattern adopted when
adults were required to walk on hands and
feet (creep) in a study aimed primarily a t
investigating economy and motor skill learning, Wider reading of studies on both animal
gait and human creeping suggested that
these data would be of interest to developmental psychologists, anthropologists, and
biomechanists. For example, a number of
studies have discussed the mechanics and
energetics of human walking from a n evolutionary perspective (Carrier, 1984; Charteris
et al., 1982; Robins and Shute, 1983; Taylor
and Rowntree, 1973; Tuttle, 1969; White and
Suwa, 1987; Wolpoff, 1983). Developmental
psychologists have studied the emergence of
the mature walking pattern through successive “stages,” such as crawling, creeping, and
assisted walking (Burnside, 1927; McGraw,
1941; Shirley, 1931;Trettien, 1900). Recently,
Thelen (1983) has sparked a resurgence of
interest in the mechanical constraints on
stepping in human infants. This paper reviews the studies relating to creeping patReceived November 2,1987; accepted June 13,1988
388
W.A. SPARROW
Fig. 1. Adult female creeping. (Reproduced from E.
Muybridge, 1955, with permission of the publisher.)
HUMAN CREEPING PATTERNS
terns in humans as well as presenting some
new data derived from calculations based on
previously published photographs and measurements. Some hitherto unpublished data
on adult creeping are also included. The significance of these findings from the point of
view of the ontogeny and phylogeny of human gait forms the discussion.
SWING AND SUPPORT PATTERNS FOR CREEPING
The earliest record of human creeping appears to be a series of photographs taken in
the Iate nineteenth century by Muybridge
(republished in 1955). These are shown in
Figure 1, and in Figure 2 is shown a series of
photographs also taken at 1/12 of a stride
cycle reproduced from Sparrow and ZrizarryLopez’s (1987) film of adult males creeping
on a motor-driven treadmill. The subject in
Figure 2 had practiced for a total of 14 min
prior to this trial. Figures 3 and 4 show two
more of Sparrow and Zrizarry-Lopez’s (1987)
subjects utilizing a gait pattern different from
that in Figure 2; these were taken after exactly 30 sec of practice.
389
Support sequence diagrams of the creeping
gaits in the photographs are shown in Figures 5 and 6. Figure 5 depicts the support
sequence of hands-and-feet for the gaits
shown in Figures 1 and 2 and also gives the
gait pattern for a n adult female creeping on
hands-and-knees (reproduced from Burnside,
1927). The single stride sequence for Muybridge’s adult female subject has been reproduced three times to be consistent with the
number of support sequences presented for
the other subjects. Figure 6 is from Sparrow
and Zrizarry-Lopez (1987) and contains the
support sequences for the subjects SK and
DW shown in the photographs (Figs. 3 and
4). In these support sequence diagrams, the
swing phase, when the limb is out of contact
with the ground, of each limb is unmarked,
and the support phase is depicted as a solid
line of length proportional to percentage of
stride duration.
Using terminology from descriptions of animal gaits (see, e.g., Garnbarian, 1974; Hildebrand, 19671, all the creeping patterns can
be described as “symmetrical.” For our pur-
Fig. 2. Adult male creeping. Subject E on day 5 from
Sparrow and Zrizarry-Lopez’s (1987)film.
390
W.A. SPARROW
3
4
HUMAN CREEPING PATTERNS
391
and following the sequence of swing phases
diagonally upward to the right.
Figure 5 shows two alternative support sequence diagrams for Muybridge’s subject. It
was difficult to determine from the photographs exactly when the limbs contacted or
left the floor; a second support sequence (Sequence 2) was therefore constructed on the
assumption that the support phase could be
one photograph (or 1/12 of a stride cycle)
longer than that represented in Sequence 1.
3URNSiDE
For example, it appears that the right foot
ADULT
IORMAL HATE
might have made contact either on photograph four or very shortly after but prior to
photograph five. It is also difficult to judge
whether photograph eight accurately repreADULT
I A P l D RATE
sents departure of the left hand from the
floor. It is noteworthy that Sequence 2 shows
a similarity to Subject DW’s day 1 trial 1
pattern in Figure 6. A possible explanation
is that Muybridge’s subject was relatively
SPARROW &
unpracticed, although she does show a tenI R I Z A R R Y LOPEZ
2
dency towards increasing the time lag between the beginning of the swing phases of
the ipsilateral hand and foot. When such a
pattern emerges clearly, it is characteristic
of the footfall Sequence 1 (Fig. 5) and those
Fig. 5. Support sequences for three adult subjects shown late in practice by the adult male subcreeping. Solid lines represent the proportion of stride jects in Figure 6.
duration in support, the spaces represent the proportion
Burnside’s adult subject used a gait patof stride duration in swing. Three complete strides are
tern in which the diagonally opposite hand
shown, starting with the beginning of the swing phase
of the right foot. For Muybridge’s subject, the same stride
and knee moved almost simultaneously. The
is reproduced three times, and alternative interpretaonly similar pattern for adults is that of SK
tions of the creeping pattern are presented as Sequence
on day 1, trial 1, shown in photographs in
1 and Sequence 2.
Figure 3 and schematically in Figure 6. It is
important to note that Burnside’s subject
poses, the most important characteristic of crept on hands and knees; this support sethe symmetrical gait is that movement of a quence might, therefore, be characteristic of
forelimb is always followed by either of the hands-and-knees creeping as opposed to the
hindlimbs. According to Hildebrand (1967), hands-and-feet mode of Muybridge’s subject
in most of the diagrams in Figures 5 and 6, and Sparrow’s and Zrizarry-Lopez’s subjects.
Support sequence diagrams in Figure 6
the gaits are “lateral-sequence,” in which
the footfall of the hindlimb is followed by the show that two subjects modified their creepforelimb on the same side and movement of ing pattern after a short period of practice.
the forelimb (upper limb) is followed by As was mentioned above, SK on day 1trial 1
movement of the contralateral (opposite side) moved hand and contralateral foot almost a t
hindlimb (lower limb). The usual sequence of the same time. By the second practice trial
events is for take-off of the right hand to be (not shown) the typical lateral pattern had
followed consecutively by the left foot, left been adopted, with the hand swing phase
hand, and right foot. This pattern of swing following that of the foot on the same side.
and support is most easily identified in Fig- Early in practice on day 1,Subject DW moved
ures 5 and 6 by starting with the right hand the ipsilateral hand and foot almost simultaneously, but by trial 2 (90 sec later) the
time lag between movement of the ipsilatera1 hand and foot had greatly increased.
Figs. 3, 4. Adult males creeping. Subject SK (Subject
2) on day 1,trial 1 and Subject DW (Subject 5) on day 1, The other subjects (SD, BR, and E) adopted
trial 1,from Sparrow and Zrizarry-Lopez’s (1987)film.
the characteristic symmetrical-lateral gait
F~gure
__
~
S u R J F C T BR
__
- - __
- - __
R . rout
L . Hdrid
~
-L
__
-R .
~
D4Y I
I T R l A L 11
R . Hand
~
__
__
__
FOOC
__
Foot
L . Hand
DAY 8
L . Foot
-
__
~
__
R . Hand
SUBJECT SK
- - -R . Foot
- - - -L.
Hand
- -L. Fool
~
~ - R . Hand
~
-
-R .
~
__
___
- L.
__
__
- - L.
- - - -R .
DAY I
[ T R I A L 1)
lFlg"rP31
_
Foot
Hand
DAY 10
Foot
Hand
SUBJECT E
- - -
R . Foot
-
- __
-
___
-
__
-
~
L . Hand
DAY 1
-L.
Foot
__
- __ R . Foot
___
__ __
L . Hand
__
- - - L . Foot
-
-
-
[TRIAL 1 )
-R.Hand
-R.
D A Y 10
Hand
within 30 sec of practice, with SD showing
remarkable consistency in both relative timing and duration of limb swing and support
phases.
Support patterns for infant creeping presented by Burnside (1927) are reproduced in
Figure 7. To produce three complete strides
for each sequence, it was necessary to add a
stride to the MJH 13 months 12 days sequence. This was done by reproducing the
first support and swing phase in Burnside's
original diagram.
The creeping pattern for these subjects is
described in_
terms of knee placement because, even though the swing phase of the
leg is initiated by the foot, they rested on the
knee during support. In some strides, the
sequence of limb movements is the symmetrical-lateral pattern described above. Sometimes, however, the contralateral limbs (e.g.,
right foot or knee and left hand) are moved
almost simultaneously, as in both the normal-rate and rapid-rate patterns for Burnside's adult subject (Fig. 5). Subject SK in
Figure 6 also showed this pattern on day 1
trial 1. With the infant subjects, there is
sometimes both this simultaneous contralatera1 arm and leg action and movement of one
limb in advance of its contralateral partner
in the same stride; the middle stride of the
infant DWC a t 13 months 9 days is the best
example.
SWING AND SUPPORT DURATIONS
SUBJECT DW
-
-R.
~
Fmt
- - L . Hand
- - L. F n t
- - - __ R. Hand
__
__
~
~
- _ _ _ __
__
__ _ _
-
-
DAY 1
I T R I A L 1)
lFigure41
R. F m t
L . Hand
- L . Foot
- __ R . Hand
- ~- - ___ L .
-
DAY 10
SUBJECT SD
R . Foot
tland
~
-
~
L . Fool
~
~
-R .
DAY 1
[ T R I A L 11
Hand
- - -R.
- - - __ -
Foot
-
Hand
Foot
L . Hand
-L.
- -
-R.
In Table I,the durations of swing and support as a percentage of stride duration are
summarized for the data from the studies
referred to above. The mean support duration and mean swing duration for the infants
are similar to the corresponding durations
for Burnside's adult. This probably reflects
the hands-and-knees creeping mode. The
Sparrow and Zrizarry-Lopez subjects show
longer support durations (and a correspondingly shorter swing phase) for both hand and
foot than do Burnside's subjects but show
durations similar to those of Muybridge's
subject, who also crept on hands and feet.
The Sparrow and Zrizarry-Lopez data are av-
DAY 10
Fig. 6. Support sequences for Sparrow and ZrizarryLopez's (1987) adult males creeping on hands and feet.
(Reproduced from effiency and metabolic cost as measures of learning a novel gross Sparrow and ZrizarryLopez, 1987, with permission of the publisher.
393
HUMAN CREEPING PATTERNS
-
__
-
~
-
-
-
-
_
_
L HAND
9 ma 19 days
L KNEE
- R HAND
KNEE
-
L HAND
_ _ -
L KNEE
-
-
KNEE
-R
~
-
--R
-
-
eraged over approximately 30 strides (33
strides for SD, SK, E, and DW and 27 strides
for BR) filmed on alternate days during a 6week practice period. They can therefore be
taken as reliable, normative data for handsand-feet creeping, with the proviso that between-subject variability is likely to be due
to the subject’s mechanical characteristics
(relative body segment lengths, strength,
etc.), degree of practice, and unexplained
idiosyncrasies of the creeping pattern.
SUBJECT MJH
-
-R
11 m a 1 day
HAND
12mo 12dayr
COMPARISONSOF CREEPING PATTERNS BASED
ON HILDEBRAND’S FORMULA
13mo l l d d y s
~
__
SUBJECT DWC
-R
KNEE
-L
HAND
12mo O d s y ~
L KNEE
R HAND
-R
-
KNEE
L HAND
13mo Odsyr
L KNEE
-R
HAND
Fig. 7. Support sequences for two infants creeping on
hands and knees. (Adapted from Burnside, 1927,2, with
permission of the publisher.)
Further comparisons of creeping patterns
can be made using Hildebrand’s (1967) gait
formula and creeping data. Figure 8 is in
part a reproduction of Hildebrand’s figure
(1967; Fig. 41, showing the creeping patterns
that he obtained for infants (n = 6, handsand-knees creeping) and children (n = 27,
6.5-11 years, hands-and-feet creeping). Gait
sequences for nonhuman primates have been
omitted from Hildebrand’s original figure
and the position of the subjects from the previous studies added as indicated. Note that,
as the points in the figure tend towards zero
on the vertical axis, the right hand and the
right foot (or knee) would be moving closer
together in time. As the points tend towards
50% on the horizontal axis, the periods of
swing and support for the right foot (or knee)
would become increasingly similar.
TABLE 1. Support and swing durations as a percentage of stride duration for hand and foot (or knee)
creeping in human infants and adults
Foot
Subject
Adults
Sparrow and
Zrizarry-Lopez
(1987)
Swing
Support
Swing
Mean
Normal
Fast
Sequence 1
75
66
62
75
71
69.8
45
40
75
25
34
38
25
29
30.2
55
60
25
66
69
66
58
69
65.6
37
40
75
34
31
34
42
31
34.4
63
60
25
Seauence 2
67
33
67
33
9,191
11,l
12,12
13,12
12,o
13,9
Mean
35
43
43
42
44
36
40.5
65
57
33
67
72
58
69
65
65
66
BR
SK
E
DW
SD
Burnside (1927)
Muybridge
(1955)
Infants
Burnside (1927)
‘Age in months, days
Hand
Support
57
58
56
64
59.5
28
42
31
35
35
34
W.A. SPARROW
394
WALK
20--
-
RUN
BR:A ,,>,\MY
E
MY s1 4 s D
i;
Lateral-
: Couplets
~
0
“y-HOMO(Children)
‘\ oMJH(11.1)
:.
0 MJH(9.19)-
DWq
P
!
E
+d
40-
--.
-._
--‘
0
HONlO(1nfants)’
1
DWC(13.9)
ADULT
MJH(12.12)
o DWC(12,O)
DiagonalCouplets
TROT
OMJH(13,12)
60-
SingleFoot
-
Z Diagonal-
5
P
Couplets
- SingleFoot
80-
8
100
I
.m Lateral0
I
I
I
I
I
I
I
Couplets
I
Fig. 8. Support sequence graph for creeping gaits.
MY S1 and MY 52, support sequences 1 and 2 for Muybridge’s female. BR, SK, DW, E, SD; adult males from
Sparrow and Zrizarry-Lopez (1987), means for approximately 33 strides over a 6-week practice period. MJH,
DWC, ADUET, Burnside’s (1927) infants with age in
months and days and single adult female creeping on
hands and knees at normal rate. HOMO (Children),
HOMO (Infants), Hildebrand‘s (1967) data showing
creeping on hands and feet (Children) and hands and
knees (Infants). (Adapted from Hildebrand, 1967, with
permission of the author.)
It is interesting to see that the adult handsand-feet creeping gaits (Muybridge, 1955;
Sparrow and Zrizarry-Lopez, 1987) fall approximately within the bounds of the handsand-feet creeping gaits of Hildebrand’s children. Burnside’s (1927) infants and his adult
female creeping on hands and knees tend
towards the diagonal-couplets and trot gait
patterns. According to Hildebrand (19671, in
the diagonal-couplets gait, footfalls of fore
and hind feet on the opposite sides of the
body are related in time as a pair. As the
patterns tend towards lateral-couplets, footfalls of fore and hind feet on the same side of
the body are related in time as a pair.
These differences in gait pattern can be
observed by comparing the swing-support sequences in Figures 5-7. Figure 5 shows the
characteristic diagonal-couplets or trot
hands-and-knees creeping gait for Burnside’s
adult and the lateral-couplets gait for the
hands-and-feet creeping subjects. Figure 6
consists almost entirely of lateral-couplets
gaits, the exceptions being the day 1 trial 1
performances of SK and DW. It is interesting
to note that, when averaged over the entire
10-daypractice period, SK’s pattern just falls
within the diagonal-couplets classification.
Thus SK’s early tendency to move the contralateral hand and foot simultaneously did
not entirely disappear with practice. In contrast, DW’s day 1trial 1performance clearly
tends towards the pace, that is, the ipsilatera1 limbs moving at the same time. The
infant gaits in Figure 7 show a mixture of
creeping styles both within and between individual support sequence diagrams.
From the data available, fhere is no obvious explanation for why Burnside’s infant
creeping patterns fall so far outside the
bounds of Hildebrand’s infants. It is possible
that Hildebrand’s infants were older than
Burnside’s; unfortunately, no ages are given
for the former. Burnside’s infant data are
also extremely variable even over an age
range of about 2-4 months. Some of the variability may be due to problems in obtaining
a fair sample of creeping strides at a given
395
HUMAN CREEPING PATTERNS
SUBJECT E
25
1
75
,Toe
On
50
I
I
SUBJECT OW
25
,Toe
On
50
JJJ
Fig. 9. Thigh and shank stick figures showing change thigh-shank figure is taken at a 5% interval of stride
in the movement pattern of the creeping gait of Sparrow duration from toe-offt o toe-off; 25%, 50%, and 75%interand Zrizarry-Lopez’s(1987) subjects with practice. Each vals and the end of the swing phase (toe on) are shown.
396
W.A. SPARROW
SUBJECT BR
25
,Toe
50
On
/,///:
15
JBJECT S K
25
,Toe
.Toe
Fig. 9. (Part 2)
On
On
50
397
HUMAN CREEPING PATTERNS
Fig. 9. (Part 3).
chronological age. Burnside’s data also produce intervals of knee support characteristic
of running in animal gaits, i.e., gaits in which
the hind limb is in support for 50%or less of
stride duration.
THIGH-SHANK COORDINATION PA’ITERNS FOR
ADULT CREEPING
not suitable for constructing stick figures. To
my knowledge, these stick figures provide
the only published record of lower limb segment configurations for creeping.
DISCUSSION
The discussion is presented in three parts.
First are some observations on the creeping
The coordination pattern of the thigh and patterns and the methodology used to collect
shank for Sparrow and Zrizarry-Lopez’s and present such data. In the following two
adults is illustrated using stick figures in sections, the significance of these findings is
Figure 9. With practice, there is a marked argued in relation to both the ontogeny and
increase in flexion of both limb segments. the phylogeny of the human gait.
Most revealing of the changes with practice
Creeping patterns and methodology
are the limb positions during swing when the
limb moves unconstrained by contact with
The distinction between creeping and
the treadmill. At toe-on on day 10, the thigh crawling has long been recognized as imporposition more closely approximates that of tant if progress is to be made in the quantiupright walking, but limited flexion of the tative analysis of the developmental
shank reflects its inability to swing freely locomotor patterns that precede independent
during the flight phase. In all subjects, the upright walking. The data reviewed and presupport phase is characterized by a decrease sented here, however, also provide a basis for
in thigh extension with practice such that distinguishing hands-and-feet creeping from
the limb is not extended as far prior to the hands-and-knees creeping. The well pracnext stride. Unfortunately, there do not ap- ticed hands-and-feet mode is characterized by
pear to be any comparable data for either foot support of approximately 60-80% of
human infants or adults. Burnside’s (1927) stride duration and tends towards the latmonograph has a sequence of high-speed film eral-sequence single-foot or lateral-couplets
frames for one of the infants, but they are support sequence (see Fig. 8, Table 1).It is
398
W.A. SPAKROW
important to note, however, that, even
though Sparrow and Zrizarry-Lopez (1987)
showed changes with practice, there remained a degree of variation between
subjects.
Hands-and-knees creeping tends towards
the diagonal-couplets, in which the contralatera1 hand and foot are moved almost simultaneously. The evidence from Burnside’s
(1927) data is that such a gait might also be
characterized by a period of support for the
knee shorter than that for the foot in handsand-feet creeping. Hildebrand’s infant data,
however, suggest a period of knee support
about the same as for adults and children
using their feet.
The major problem in reviewing the literature on creeping and crawling is the lack of
a consistent methodology for collecting and
presenting the data. In this regard, Burnside
(1927)should be regarded as a pioneer in the
quantitative analysis of the development of
walking. The support sequence diagrams,
similar to those used by students of quadrupedal gaits, provide a valuable method For
assessing both qualitative and quantitative
aspects of creeping. The quantitative measure is swing and support as a percentage of
stride duration, represented by the length of
line or space in the diagram. The qualitative
aspects can be judged according to when each
limb begins its swing and support phase. Hildebrand’s (1987) formula, represented in
Figure 8, is also a convenient method for
comparing the creeping styles of a number of
subjects.
With respect to data collection, it is useful
to use high-speed film or modern optoelectric
recording devices. Such techniques have the
advantage of providing a description of the
movement pattern of the various limb segments, such as that presented in Figure 9.
More detailed and sensitive measures of differences in gait style both within and between subjects can be obtained using relative
motion plots (see, e.g., Sparrow and ZrizarryLopez, 1987; Sparrow et al., 1987).
Ontogmetic clcvelopment of walking
Descriptions of progression in the normal
upright walking of infants and young children have become fairly common in recent
years (e.g., Amano et al., 1983; Grieve and
Gear, 1966; Statham and Murray, 1971;
Sutherland, 1984), and these investigations
have uniformly used accepted gait cycle mea-
sures with which to present the findings.
Even though Trettien (1900) made some observations on infant creeping patterns almost a century ago, the study of creeping and
crawling has not enjoyed such progress despite the fact that these activities appear to
be necessary precursors to normal upright
walking. This lack of progress may stem in
part from the problem discussed earlier,
which is lack of a consistent methodology for
collecting and presenting the data from studies of creeping. Shirley (1931), for example,
gave credit to Burnside’s method of using
films to obtain a description of limb movements. Despite this, her account of the development of upright walking (Shirley, 1931)
was based only on measures of length and
width of step. Her technique did not allow for
records of duration of step-cycle phases or of
the movement pattern of limb segments.
Similarly, McGraw’s (1941) study documented nine developmental phases for creeping and crawling based on live observation
and filmed records. Despite apparently being
reliably classified according to characteristics of the movement pattern, there were no
quantitative measures of the child’s mode of
posture or progression. The studies by Burnside (1972) and Hildebrand (1987) that did
present quantitative descriptions of creeping
both showed considerable variability in the
creeping patterns within and between subjects. The apparent lack of agreement between these studies regarding the pattern of
infant creeping further qualifies the implicit
proposal that there is a universal sequence
of clearly identifiable antecedent stages for
walking. When using the labels “creeping”
and “crawling” to describe the developmental
progression towards upright locomotion, it is
important to be aware that there are few
data to show qualitative changes in the
movement pattern.
With the aid of support sequence diagrams,
it might be possible to delimit criteria for
qualitative and quantitative changes in the
creeping gaits. From the support sequences
shown in Figure 8, it appears that the handsand-knees creeping mode, characteristic of
infants, is usually the lateral-sequence diagonal-couplets pattern. The lateral-couplets
gait can presumably be adopted only when
the subject has strength sufficient to maintain support on the feet. It is a n open question, however, whether children normally
show a progression from hand-and-knees
creeping to hands-and-feet. McGraw’s (19411
HUMAN CREEPING PATTERNS
drawing of the most advanced phase of prone
progression (Phase I) shows a child creeping
on hands and knees on the left of the figure
and a child creeping on hands and feet on the
right. Unfortunately, she classified subjects
as attaining Phase I if any mode of well coordinated creeping was observed. From these
data, therefore, it is impossible to determine
how many infants used the hands and feet
gait. Likewise, Hildebrand (1987) does not
give enough information to determine
whether the babies that he studied showed
systematic progress towards the hands and
feet gait. It is reasonable, nevertheless, to
propose that the hands-and-feet creeping pattern is a more advanced stage in the development of walking with the characteristic
lateral-couplets footfall pattern as described
above.
It is interesting to speculate on the cause
of the transition from the hands-and-knees
gait to hands-and-feet and also the transitions within a creeping mode, such as from
the diagonal-couplets to the lateral-couplets
sequence. Are such changes in infant creeping patterns primarily due to nervous system
maturation or are they a consequence of
changes in the structure and composition of
the body. In sympathy with Shirley’s (1931)
study of indices of body build and the onset
of walking, Thelen (1983) argued that upright walking emerges as a consequence of
overcoming biomechanical constraints, such
as strength relative to limb mass; shift in
whole-body center of gravity; and changes in
relative length and mass of limbs, head, and
trunk. It seems likely that similar constraints would influence the chronological
onset, duration, and support pattern of creeping and crawling. Such activities may be necessary precursors to upright locomotion in
providing the necessary exercise and
strengthening of the musculature.
Another explanation for changes in infant
movement patterns, particularly in high-energy-demanding activities such as locomotion, is that the infant learns to adopt a more
economical movement pattern in response to
the metabolic energy demands of the activity. While not denying the influence of nervous system maturation, Thelen’s (1983)
“biodynamic” factors, and the infant’s motivation to explore, it is also reasonable to propose that the course of locomotor development in infancy and childhood is in part a
response to the metabolic energy required to
transport the body.
399
Phylogenetic development of walking
The evolution of hominid bipedalism is a
topic that has attracted considerable interest
from anthropologists and workers in other
scientific domains. For example, kinesiological descriptions of normal walking have been
used to extrapolate the locomotor characteristics of hominids from measurements of fossilized footprints (Charteris et al., 1982; Day
and Wickens, 1980; Tuttle, 1987). The key
data in the Charteris et al. (1982) study of
the Laetoli Pliocene hominid footprints are
the original measurements of stride length
and foot length. The numbers of foot lengths
per stride in the three Pliocene hominid trails
were 4.18, 4.39, and 4.00 at estimated absolute walking speeds of 0.56,0.72, and 0.42 m/
sec, respectively. These values are within the
normal range for contemporary young adults,
albeit at a slow pace (“strolling”). For Sparrow and Zrizarry-Lopez’s (1987) subjects,
creeping on hands-and-feet a t 0.76 d s e c , the
number of foot lengths per stride is in the
range of 7.3-10.9. In creeping, the foot stride
length is therefore very long compared to the
stride length when walking upright a t about
the same speed. Sparrow and Zrizarry-Lopez
(1987) show that creeping is characterized by
stride length and stride duration about 45%
greater than that for normal upright walking a t the same speed. These observations
suggest that any form of quadrupedal hominoid gait would be likely to have a similarly
large number of foot lengths per stride.
A kinesiological description of creeping is
also useful in view of the hypothesis that the
evolution of our erect locomotor style passed
through a distinctive stage of habitual knuckle-walking. Most of the controversy surrounding our proposed knuckle-walking
ancestor has originated from comparative
anatomical studies of apes and humans (see
Tuttle, 1974, for a review). In this context, it
is interesting to observe the lack of similarity between human creeping gaits and the
quadrupedal gaits of nonhuman primates. As
Hildebrand (1967)points out, “. . . adult monkeys and apes favor the very gaits that are
avoided by infant humans” (p. 127). The unfavored gaits are the diagonal-sequences in
which the footfall of the hindfoot is followed
by the forefoot on the opposite side of the
body. Such gaits are unlike any of the creeping gaits presented above. In the well practiced adult hands-and-feet creeping gaits,
contact of the foot is always followed by con-
400
W.A. SPARROW
tact of the ipsilateral hand. In the hands-andknees gaits, the tendency is to move contralateral hand and knee simultaneously. If,
therefore, the creeping gait of contemporary
Homo sapiens is viewed as a vestige of earlier quadrupedal locomotion, then it is necessary to explain not only the evolution of
upper limb and lower limb anatomy but also
the fact that creeping in contemporary humans is of a different pattern and is highly
inefficient compared to quadrupedal locomotion in nonhuman primates. Based on a n examination of the anatomical constraints on
knuckle-walking, Tuttle (1969) suggested
that humans did not pass through a knucklewalking (quadrupedal) stage. Instead, a bipedal posture was assumed very soon after
abandoning some form of suspensory
posturing.
The anatomical and kinesiological evidence cited above takes a position against a n
extended evolutionary period of habitual
quadrupedal gait during which the knuckles
provided support for the forelimbs. It seems
reasonable to speculate, however, on whether
palmigrade locomotion might have been favored during the transition to fully fledged
bipedal gait. Well trained human adult subjects suffer little stress in the hands and
wrists when creeping, even though the load
is predominantly on the posterior part of the
palm, with little force being absorbed by the
fingers.
It has been suggested that bipedal locomotion was adopted by our ancestors as a response to considerations of energy efficiency.
For contemporary Homo sapiens, creeping (on
hands and feet) is highly inefficient in terms
of rate of metabolic energy expenditure required to travel a t a set speed. The subjects
in Sparrow and Zrizarry-Lopez’s (1987) study
were highly practiced but expended metabolic energy about four times faster than
would be necessary for walking upright a t
the same speed. The muscular and cardiovascular stress induced is such that a physically
fit, well practiced male can creep only for a
maximum of about 20 min at 2.7 km/hr (1.7
mph). Taylor and Rowntree (1973) outline a
debate among anthropologists on the evolutionary checks and balances involved as our
forebearers adopted a n upright gait. Using
two chimpanzees as subjects, they found no
difference in the energetic cost of locomoting
on two or on four legs, concluding that the
emergence of bipedal locomotion would not
incur a decrease in locomotor economy. This
implies that only when other evolutionary
expedients encouraged change in the anatomy and mechanics of the body would quadrupedal locomotion become less favored
because of the extra energy cost.
CONCLUSIONS
The study of creeping appears to have the
potential to assist in understanding the processes involved in the ontogeny and phylogeny of walking. Creeping seems to be a n
important antecedent to independent upright locomotion, but the nature and function
of the activity are poorly understood. The
body of research dealing with creeping and
crawling is diverse and suffers from the lack
of a consistent methodology. From the point
of view of the phylogeny of the contemporary
human gait, the study of creeping reveals a
few issues of interest. The support-sequence
patterns are different from those of monkeys
and apes. When compared with normal upright walking a t the same speed, creeping is
about four times less efficient and is generated by strides of double the length. In view
of the arguments against the knuckle-walking hypothesis, it would be interesting to
know whether anatomical studies provide
any support for the proposal that palmigrade
locomotion was favored by early hominids.
ACKNOWLEDGMENTS
I thank Russell Tuttle for providing some
valuable references to assist in improvements to the initial draft of the article. Two
other reviewers provided comments that significantly improved the paper. I am also
grateful to Karl Newel1 for drawing my attention to Muybridge’s creeping photographs.
LITERATURE CITED
Amano Y, Mizutani S, and Hoshiknwa T (1983) Longitudinal study of running of 58 children over a fouryear period. In H Matsui and K Kobayashi (eds.): Bio
mechanics VII-B. Champaign, IL: Human Kinetics
Publishers, pp. 663-668.
Ames LB (1937) The sequential patterning of prone progression in the human infant. Genet. Psychol. Monogr.
19:409-460.
Bobbert AC (1960)Energy expenditure in level and grade
walking. J. Appl. Physiol. 15r1015-1021.
Burnside LH (1927) Coordination in the locomotion of
infants. Genet. Psychol. Monogr. 2~284-372.
Cappozo A, Figura F, Marchetti M, and Pedotti A (1976)
The interplay of muscular and external forces in human ambulation. J. Biomechan. 6~35-43.
Carrier DR (1984) The energetic paradox of human running and hominid evolution. Curr. Anthropol. 25.483495.
HUMAN CREEPING PATTERNS
Cavagna GA (1973) Human locomotion. In L Bolis, K
Schmidt-Nielsen, and SHP Maddress (eds.): Comparative Physiology. Amsterdam: North-Holland, pp. 4362.
Cavama GA. and Kaneko. M. (1977) Mechanical work
andvefiiciency in level walking and running. J. Physiol. 268:467-481.
Charteris J, Wall JC and Nottrodt JW (1982) Pliocene
hominid gait: New interpretations based on available
footprint data from Laetoli. Am. J. Phys. Anthropol.
58: 133-144.
Cotes EN, and Meade F (1960) The energy expenditure
and mechanical energy demand in walking. Ergonomics 3r97-119.
Day MH and Wickens EH (19801Laetoli Pliocene hominid footprints and bipedalism. Nature 286t385-387.
Dean GA (1965) An analysis of the energy expenditure
in level and grade walking. Ergonomics 8:31-47.
Donovan CM and Brooks GA (1977) Muscular efficiency
during steadyrate exercise H. Effects of walking speed
and work rate. J. Appl. Physiol. 43r431-439.
Gambarian PP (1974) How Mammals Run: Anatomical
Adaptations. New York: Halsted Press.
Grieve DW and Gear R J (1966)The relationship between
length of stride, step frequency, time of swing and
speed of walking for children and adults. Ergonomics
5.379-399.
Hildehrand M (1967)Symmetrical gaits of primates. Am.
J. Phys. Anthropol. 26t119-130.
Margaria R (1976)Biomechanics and Energetics of Muscular Exercise. Oxford Clarendon Press.
McGraw MB (1941) Development of neuro-muscular
mechanisms as reflected in the crawling and creeping
behavior of the human infant. J. Genet. Psychol. 58233111.
Muybridge E (1955) The Human Figure in Motion. New
York: Dover (originally published in 1899).
Pierrynowski MR, Norman RW and Winter DA (1981)
Mechanical energy analyses of the human during load
carriage on a treadmill. Ergonomics 24:l-14.
Ralston H J (1976) Energetics of human walking. In RM
Herman, S Grillner, PSG Stein, and DG Stuart (eds.):
Neural Control of Locomotion. New York: Plenum
Press, pp. 77-98.
Robins G, and Shute GCD (1983) The physical proportions and living stature of New Kingdom Pharaohs. J.
Hum. Evol. 12t455-465.
Rosenrot P, Wall JC, and Charteris J (1980)The relationship between velocity, stride time, support time and
swing time during normal walking. J. Hum. Movement Stud. 6:323-335.
401
Shapiro DC, Zernicke RF, Gregor RJ, and Diestel JD
(1981)Evidence for generalized motor programs using
gait pattern analysis. J. Mot. Behav. 13:33-47.
Shirley MM (1931) The First Two Years. A Study of
Twenty-Five Babies. Vol. 1. Postural and Locomotor
Development. Westport CT: Greenwood Press
Publishers.
Sparrow WA, Donovan E, van Emmerik R, and Barry B
(1987) Using relative motion plots to measure changes
in intra-limb and inter-limb coordination. J. Motor Behav. 19t115-119.
Sparrow WA, and Zrizarry-Lopez VM (1987) Mechanical
efficiency and metabolic cost as measures of learning
a novel gross motor task. J. Motor Behav. 19r240-264.
Statham L, and Murray MP (1971) Early walking patterns of normal chiIdren. Clin. Orthopaed. Related Res.
79:8-24.
Sutherland DM (1984)Gait Disorders in Childhood. Baltimore: Williams & Wilkins.
Taylor CR, and Rowntree V J (1973) Running on two or
on four legs: which consumes more energy? Science
179: 186-1237,
Thelen E (1983) Learning to walk is still an “old” problem: A reply to Zelazo (1983). J. Motor Behav. 15t139161.
“rettien AW (1900) Creeping and walking. Am. J. Psychol. 121-57.
Tuttle R (1969) Knuckle-walking and the problem of
human origins. Science 166:953-961.
Tuttle R (1974) Darwin’s apes, dental apes, and the descent of man: Normal science in evolutionary anthropology. Curr. Anthropol. 15t9-426.
TuttIe R (1987) Kinesiological inferences and evolutionary implications from Laetoli bipedal trails G-1, G-2/3
and A. In MO Leakey and J M Harris (eds.): Laetoli a
Pliocene site in Northern Tanzania. Oxford: Clarendon
Press, pp. 503-523.
Vilensky JA, and Gehlsen G (1984) Temporal gait parameters in humans and quadrupeds: How do they
change with speed? J. Hum. Movement Stud. lOr175188.
White TD, and Suwa G (1987) Hominid footprints at
Laetoli: Facts and interpretations. Am. J. Phys. Anthropol. 78r485-514.
Winter DA (1984) Kinematic and kinetic patterns in
human gait: variability and compensating effects.
Hum. Movement Sci. 3 5 - 1 6 .
Wolpoff MH (1983) Lucy’s little legs. J. Hum. Evol.
12:443-453.
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