Gender-related gait differences in Down syndrome
145
Gait tests were performed within the gait
analysis laboratory of the IRCCS San Raffaele
Hospital (Rome, Italy), equipped with a 12-camera
motion capture system (Elite 2002, BTS, Milan,
Italy); 22 spherical reflective markers were placed
on patients’ body according to the Davis protocol.
Participants were requested to walk at comfortable
speed 6 times on a 10-m lane. Anthropometrics
and intellectual quotient (IQ) were obtained
through the Wechsler’s Intelligence Scale for
Children (WISC-III) and Adult Intelligence Scale
(WAIS-R), according to participant’s age (16).
Data and statistical analysis
Fig. 1. Sex differences in joints Gait Variable Score (GVS). A/P, Rot and U/D: pelvic
tilt, rotation and obliquity, respectively; F/E: flexion/extension. Significant differences
between male and female patients with Down Syndrome: *p < 0.05 and **p < 0.01,
corrected for the effects of age, speed and body mass index (BMI).
The following spatiotemporal gait parameters were
obtained: speed, cadence, step length and step width
(normalized by body stature), %stance, %swing.
Gait Profile Score (GPS) and Gait Variable Scores (GVSs) rela-
tive to pelvis and lower limbs were computed to account for the
distance of angular kinematic from a healthy reference popula-
tion (17), on a global and joint-level perspective. A GPS ≤ 7° is
considered normative for healthy people (18). Variables were
submitted to multivariate analyses of covariance (MANCOVA) to
test sex-related differences, taking age, speed and BMI as covari-
ates. A significance level of 0.05 was implemented throughout.
DISCUSSION
This study suggests that, in people with DS, global
gait function tends to be more impaired in females
than in males. Sex-specific features were found in the
sagittal plane at the pelvis, hip and knee level, and in
the transverse plane at the pelvis, hip and foot level.
Overall, patients’ GPS was > 10°, denoting a general
picture of impaired gait (18). The largest GVSs (hip
and knee flexion, hip and foot rotation) matched the
RESULTS
common gait phenotype of patients with DS (4, 9, 10).
Male and female patients with DS showed similar
IQ ranged from 33 to 91 (first quartile 60, third quar-
cadence
and normalized step width, as in (19), but
tile 73), with no sex differences (p = 0.616) nor age/
shorter
step
length. This agrees with previous observa-
speed effect (p = 0.059 and p = 0.360, respectively). In
tions
showing
that healthy females walk with a shorter
both males and females BMI increased, and cadence
step
length
(12,
20), also when taking dimensionless
decreased with age (sex factor, p > 0.05, age factor:
(normalized)
measures
(21). Gait speed was comparable
p < 0.001). Speed, normalized speed, step width, %
in
males
and
females,
together with BMI and IQ. As
stance and % swing were similar in male and female
speed
has
a
substantial
effect on gait kinematics (11),
patients (p > 0.05, Table I), while step length was slight-
the
observed
differences
in the motion of the joints
ly shorter in females (p < 0.001). In female patients,
cannot
be
ascribed
merely
to speed-size mismatches,
GPS was, on average, 12% higher (p < 0.001) with no
nor
to
cognitive
function.
Rather,
a sex-specific move-
significant effect of age, speed and BMI; the GVS of
ment
pattern
emerged
from
multi-plane
joints motion:
pelvic tilt (p < 0.001), pelvic rotation (p = 0.021), hip
in
females,
sagittal-plane
joint
kinematics
was more
flexion (p < 0.001), and knee flexion (p = 0.033) were
altered
at
the
pelvis,
hip
and
knee
level;
pelvis
and hip
higher than in males (Fig. 1). The GVS of foot rotation
rotation
and
pelvis
tilt
were
also
impaired;
an
opposite
was higher in males (p = 0.046).
trend was found on foot progression, as the
corresponding GVSs was higher in men.
Table I. Sex-related differences (mean and standard deviation on the whole
These results further confirm recent
sample) in gait parameters, corrected for the effects of age, gait speed and body
observations
showing that women with
mass index (BMI)
DS tend to have larger hip flexion at late
p
Males
Females
p (covariates)
stance and reduced knee flexion at early
(group)
(n = 127)
(n =103)
swing, while men showed larger foot
Mean (SD)
Mean (SD)
Sex
Age
Speed BMI
extra rotation at late swing (15). Hip
Speed, m/s
0.74 (0.17)
0.71 (0.18)
0.255
0.284 –
0.055
Speed, normalized, 1/s
0.50 (0.11)
0.52 (0.13)
0.191
0.550 –
< 0.001
and knee flexion deficits are probably
Cadence (step/min)
101.3 (13.9)
101.8 (16.7)
0.205 < 0.001 < 0.001 0.025
associated, as in healthy women, with
Step length, normalized
0.303 (0.046)
0.295 (0.051) < 0.001
0.298 < 0.001 < 0.001
Step width, normalized
0.117 (0.037)
0.121 (0.039) 0.746
0.841 < 0.001 0.809
weaker abdominal (20) and hip flexor
% stance
59.5 (2.4)
59.5 (2.9)
0.282
0.939 < 0.001 0.040
(22) muscles. Altered foot progression is
% swing
40.5 (2.4)
40.6 (2.5)
0.128
0.759 < 0.001 0.060
common in DS due to flatfoot (4), and its
GPS, °
10.1 (1.7)
11.5 (2.2)
<0.001
0.293
0.119 0.357
prevalence is higher in male patients (23):
GPS: Gait Profile Score; normalized: divided by participant’s stature; p: multivariate analysis of
covariance (MANCOVA); SD: Standard deviation.
this may explain the higher foot progres-
J Rehabil Med 51, 2019