Article

Our aim was to investigate muscle architecture and size of the rectus
femoris (RF) and vastus lateralis (VL) in children and adolescents with cerebral
palsy (CP) compared with age-matched typically developing participants. METHOD:
Muscle architecture and size were measured with ultrasound imaging in 18
participants with spastic CP (9 females, 9 males; age range 7.5-19 y; mean age 12
y [SD 3 y 2 mo]) within Gross Motor Function Classification System levels I
(n=4), II (n=2), III (n=9), and IV (n=3) and 12 typically developing participants
(10 females, 2 males; age range 7-20 y; mean age 12 y 4 mo [SD 3 y 11 mo]).
Exclusion criteria were orthopedic surgery or neurosurgery within 6 months before
testing or botulinum toxin injections to the quadriceps within 3 months before
testing. RESULTS: RF cross-sectional area was significantly lower (48%), RF and
VL muscle thickness 30% lower, RF fascicle length 27% lower, and VL fascicle
angle 3 degrees less in participants with CP compared to the typically developing
participants (p<0.05). Intraclass correlation coefficients were >or=0.93 (CP) and
>or= 0.88 (typical development), indicating excellent reliability.
INTERPRETATION: These results provide the first evidence of altered muscle
architecture and size of the RF and VL in CP, similar to patterns observed with
disuse and aging. These alterations may play a significant role in the decreased
capacity for force generation as well as decreased shortening velocity and range
of motion over which the quadriceps can act.

Langue : ANGLAIS