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A. Picelli et al.
Table I. Demographic and clinical features of patients
Patients’ features
Age, years, mean (SD)
Sex, male/female, n
Time since stroke onset, years, mean (SD)
Affected lower limb trochanter length, cm, mean (SD)
Affected ankle dorsiflexion PROM, °, mean (SD)
Calf muscles spasticity
MAS (0–5), median (IQR)
TS grade (0–4), median (IQR)
TS angle, °, mean (SD)
Calf muscles echo intensity (Heckmatt grade 1–4)
Gastrocnemius medialis, median (IQR)
Gastrocnemius lateralis, median (IQR)
Soleus, median (IQR)
Tibialis posterior, median (IQR)
69.1 (7.9)
17/8
5.5 (3.4)
78.1 (5.6)
–5.4 (5.8)
3.0 (2.0; 4.0)
2.0 (2.0; 3.0)
8.4 (5.5)
2.0
2.0
2.0
2.0
(2.0;
(2.0;
(2.0;
(1.5;
3.0)
2.5)
3.0)
3.0)
SD: standard deviation; PROM: passive range of motion; MAS: Modified
Ashworth scale; TS: Tardieu scale; IQR: interquartile range.
interruption of the passive movement, followed by release; 3:
fatigable clonus occurring at a precise angle; 4: unfatigable
clonus occurring at a precise angle), and the TS angle, which
measured the difference between the angle of catch-and release/
clonus at fast stretch in dorsiflexion and the ankle PROM (18).
(lateral to the virtual line extending from the middle of
popliteal fossa to the Achilles tendon insertion), and 1.0
cm (SD 0.3) deep (distance from the skin). The mean
coordinates for the soleus motor branch were 1.4 cm
(SD 1.1) vertical (distal to the fibular head), 1.6 cm
(SD 0.7) horizontal (lateral to the virtual line extending
from the middle of popliteal fossa to the Achilles tendon
insertion), and 2.8 cm (SD 0.7) deep (distance from the
skin). The mean coordinates for the tibialis posterior
motor branch were 4.3 cm (SD 1.5) vertical (distal to
the fibular head), 1.9 cm (SD 0.9) horizontal (lateral to
the virtual line extending from the middle of popliteal
fossa to the Achilles tendon insertion), and 4.2 cm (SD
0.8) deep (distance from the skin). US images of tibial
motor nerve branches to the gastrocnemii, soleus and
tibialis posterior muscles are shown in Fig. 1.
Table II shows the results of the correlation between
anatomical landmarks of the tibial nerve motor bran-
ches and other US and clinical features (Spearman’s
rank correlation test).
Statistical analysis
Statistical analysis was performed using the Statistical Package
for Social Science for Macintosh, version 20.0 (SPSS Inc, Chi-
cago, IL, USA). Descriptive statistics were used to define the
tibial nerve motor branches location in the space. Spearman’s
rank correlation test was used to assess the association between
anatomical landmarks of the tibial nerve motor branches and
other US and clinical features of patients. The alpha level for
significance was set at p < 0.05.
DISCUSSION
For patients with spastic equinovarus foot, DNB of
the tibial nerve and its motor branches is mandatory to
determine the causes of the muscle overactivity pattern
and to define its management appropriately (6, 8). In
particular, DNB of the tibial nerve main trunk (mixed
RESULTS
A total of 25 chronic stroke
patients were recruited from
among 78 consecutive outpa-
tients. The enrolment period was
from March to June 2017. The
patients’ demographic and clini-
cal features are shown in Table I.
The mean coordinates for the
gastrocnemius medialis motor
branch were 1.5 cm (standard de-
viation (SD) 2.7) vertical (proxi-
mal to the fibular head), 1.7 cm
(SD 1.3) horizontal (medial to
the virtual line extending from the
middle of popliteal fossa to the
Achilles tendon insertion), and 1.1
cm (SD 0.4) deep (distance from
the skin). The mean coordinates
for the gastrocnemius lateralis mo-
tor branch were 0.9 cm (SD 2.2)
vertical (proximal to the fibular
head), 1.8 cm (SD 1.7) horizontal
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Fig. 1. Ultrasound images of: (A) the tibial nerve trunk, and its motor branches to (B) the gastrocnemii
muscle, (C) soleus muscle, and (D) tibialis posterior muscle.