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Characterization of spasticity in cerebral palsy: dependence of catch angle on velocity
Author(s) -
WU YINING,
REN YUPENG,
GOLDSMITH ASHLEE,
GAEBLER DEBORAH,
LIU SHU Q,
ZHANG LIQUN
Publication year - 2010
Publication title -
developmental medicine and child neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.658
H-Index - 143
eISSN - 1469-8749
pISSN - 0012-1622
DOI - 10.1111/j.1469-8749.2009.03602.x
Subject(s) - spasticity , cerebral palsy , spastic , gross motor function classification system , range of motion , medicine , spastic cerebral palsy , elbow , physical medicine and rehabilitation , physics , physical therapy , surgery
Aim To evaluate spasticity under controlled velocities and torques in children with cerebral palsy (CP) using a manual spasticity evaluator. Method The study involved 10 children with spastic CP (six males, four females; mean age 10y 1mo, SD 2y 9mo, range 7–16y; one with quadriplegia, six with right hemiplegia, three with left hemiplegia; Gross Motor Function Classification System levels I [ n =2], II [ n =3], III [ n =2], IV [ n =2], and V [ n =1]; Manual Ability Classification System levels II [ n =5], III [ n =4], and V [ n =1]) and 10 typically developing participants (four males, six females; mean age 10y 3mo, SD 2y 7mo, range 7–15y). Spasticity and catch angle were evaluated using joint position, resistance torque, and torque rate at velocities of 90°, 180°, and 270° per second, controlled using real‐time audio‐visual feedback. Biomechanically, elbow range of motion (ROM), stiffness, and energy loss were determined during slow movement (30°/s) and under controlled terminal torque. Results Compared with typically developing children, children with CP showed higher reflex‐mediated torque ( p <0.001) and the torque increased more rapidly with increasing velocity ( p <0.001). Catch angle was dependent on velocity and occurred later with increasing velocity ( p =0.005). Children with CP showed smaller ROM ( p <0.05), greater stiffness ( p <0.001), and more energy loss ( p =0.003). Interpretation Spasticity with velocity dependence may also be position‐dependent. The delayed catch angle at higher velocities indicates that the greater resistance felt by the examiner at higher velocities was also due to position change, because the joint was moved further to a stiffer position at higher velocities.