Article

OBJECTIVE: To compare muscle endurance in adolescents with spastic cerebral palsy
(CP) with typically developing (TD) peers using a submaximal
repetitions-to-fatigue (RTF) protocol. DESIGN: Cross sectional. SETTING: Human
motion laboratory. PARTICIPANTS: Adolescents with spastic CP (n=16; Gross Motor
Function Classification System levels I or II) and TD adolescents (n=18) within
the age range of 12 to 19 years old. INTERVENTIONS: Not applicable. MAIN OUTCOME
MEASURES: Each participant performed 3 RTF tests at different submaximal loads,
ranging from 50% to 90% of their maximal voluntary knee extension torque. The
relation between the number of repetitions (repetition maximum [RM]) and imposed
submaximal relative (percent of maximal voluntary torque [%MVT]) and absolute
(Nm/kg) torque was quantified. To compare adolescents with CP with TD
adolescents, a mixed linear model was used to construct load endurance curves.
Surface electromyography of quadriceps muscles was measured to assess changes in
normalized amplitude and median frequency (MF) as physiological indicators of
muscle fatigue. RESULTS: Adolescents with CP showed a larger decrease in %MVT per
RM than TD adolescents (P<.05). TD adolescents showed substantial higher absolute
(Nm/kg) load endurance curves than adolescents with CP (P<.001), but they did not
show a difference in slope. Electromyographic normalized amplitude increased
significantly (P<.05) in the quadriceps muscles in all tests for both groups.
Electromyographic MF decreased significantly (P<.05) in tests with the low and
medium loads. Electromyographic responses did not differ between groups,
indicating that similar levels of muscle fatigue were reached. CONCLUSIONS:
Adolescents with CP show slightly lower muscle endurance compared with TD
adolescents on a submaximal RTF protocol, which is in contrast with earlier
findings in a maximal voluntary fatigue protocol. Accordingly, adolescents with
CP have a reduced capacity to endure activities at similar relative loads
compared with TD adolescents.
CI - Copyright (c) 2014 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS