Article

During multilevel surgery, muscle-tendon lengthening (MTL) is commonly carried
out in children with cerebral palsy. However, it is unclear if MTL also modifies
increased muscle tone and if pathologic activation patterns are changed as an
indirect effect of the biomechanical changes. Since investigations addressing
this issue are limited, this study aimed at evaluating the effects of MTL on
muscle tone and activation pattern. Forty-two children with spastic diplegia who
were treated by MTL underwent standardized muscle tone testing (modified Ashworth
and Tardieu test), dynamic EMG and three-dimensional gait analysis before, one
and three years after MTL. For the evaluation of muscle activation patterns the
norm-distance of dynamic EMG data was analyzed. Range of motion and joint
alignment in clinical examination were found to be significantly improved one
year after MTL. However, deterioration of these parameters was noted after three
years. Muscle tone was significantly reduced one year postoperatively but showed
an increase after three years. Joint kinematics were found significantly closer
to reference data of age matched controls initially after surgery, but
deteriorated until three years postoperatively. However, the EMG patterns of the
muscles which were surgically addressed were found to be unchanged in either
follow-up. These findings suggest that despite the influence of MTS on
biomechanics and physiology (muscle tone reduction and improvements of joint
mobility and gait pattern) MTS does not change abnormal patterns of muscle
activation. Recurrence of increased muscle tone and deterioration of kinematic
parameters three years after surgery may be attributed to these persistent
pathologic activation patterns.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS