Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 18

Effect of AFOs on tibialis anterior EMG
Table II. Area under the curve (AUC) of the tibialis anterior muscle and walking speed for the early and delayed group (T1–T4); the
mixed model repeated measures analysis within and between groups; and the independent samples t-test between the early and delayed
group at T4
Mixed model repeated
measures analysis a
Early group
Delayed group
T1 (n  = 14) T2 (n  = 15) T3 (n  = 14) T4 (n  = 15) T1 (n  = 7) T2 (n  = 11) T3 (n  = 11) T4 (n  = 11)
AUC of the tibialis anterior, µV, median (IQR)
Without AFO
SW
21 (11;63) 24 (7;62)
22 (8;63)
DS1
12 (5;58)
20 (4;61)
17 (7;67)
SS
5 (3;21)
8 (3;12)
8 (4;19)
DS2
13 (3;24)
14 (3;43)
20 (4;64)
With AFO
SW
14 (4;64)
24 (2;53)
15 (4;64)
DS1
7 (4;43)
21 (5;51)
14 (4;47)
SS
4 (3;10)
9 (3;13)
7 (4;18)
DS2
6 (3;25)
14 (3;36)
16 (4;47)
33
23
12
22
(9;81)
(12;64)
(6;20)
(6;52)
18 (6;91)
30 (9;82)
8 (6;21)
24 (5;56)
Walking speed, m/s, mean (SD)
Without AFO
0.37 (0.19) 0.53 (0.29) 0.56 (0.29) 0.60 (0.31)
With AFO
0.38 (0.17) 0.56 (0.28) 0.58 (0.30) 0.64 (0.31)
43 (26;67) 40 (17;90)
23 (7;59) 31 (8;49)
9 (5;34)
8 (6;32)
29 (22;50) 31 (10;46) 45
45
22
39 (25;98)
(22;68)
(9;47)
(20;63) 40
21
11
36 (16;121)
(8;105)
(5;42)
(14;48)
–
–
–
– 43 (16;85)
32 (9;48)
5 (6;30)
30 (15;66) 40
21
15
39 (14;112)
(9;81)
(6;41)
(14;63)
37 (16;89)
19 (8;49)
7 (5;36)
23 (9;50)
Within groups
Between
Early, Delayed, groups
p-value p-value p-value Independent
samples
t-test b
T4, p-value
0.420
0.922
0.531
0.404 0.310
0.975
0.760
0.225
0.282
0.013
0.007
0.248
0.987
0.119
0.117
0.912
0.207
0.921
0.445
0.192
0.40 (0.25) 0.39 (0.21) 0.51 (0.24) 0.58 (0.26)
–
0.40 (0.20) 0.58 (0.24) 0.63 (0.26)
a
For tibialis anterior, median (IQR) values are presented. Statistical test based on logarithmic transformed data and walking speed included as confounder;
b
Statistical test based on logarithmic transformed data.
AFO: ankle-foot orthosis.
Effects of early vs delayed provision of ankle-foot
orthoses
After 26 weeks (T4), no differences in TA muscle
activity between both groups were found in SW (in-
dependent samples t-test p = 0.310 and p = 0.207 for
without and with AFO, respectively) or any of the other
sub-phases of gait (p ≥ 0.192 in all cases). Furthermore,
mixed-model repeated measures analysis between-
groups shows that changes in TA activity during the
26-week follow-up period were not different between
the early and delayed group in SW (p = 0.987) or any
of the other sub-phases of gait (see Table II).
Effects of use of ankle-foot orthoses within a single
measurement session
TA activity without and with AFO were compared at
T4 for the total group (n = 26) to study the effects of
AFO use within a measurement. AFO use significantly
15
Fig. 2. Boxplots of tibialis anterior area under the curve (AUC) without ankle-foot orthoses (AFO). AUC is presented per sub-phase, for the early
(left) and delayed (right) group separately. Circles and asterisks represent outliers and extreme outliers, respectively
J Rehabil Med 51, 2019