The major postural dysfunction of children with CP is
the substantially reduced capacity to modulate the degree
of postural muscle contraction to the specifics of the
situation (Brogren et al., 2001; Van der Heide et al., 2004;
Woollacott et al., 2005). Children with CP have for
instance difficulties in using information stemming from
the initial body configuration to adapt postural activity
during reaching while sitting (Van der Heide et al., 2004).
Children with spastic hemiplegia are able to use the
information of the body configuration to some extent to
modulate postural activity during reaching; children with
bilateral spastic CP lack this capacity entirely (Van der
Heide et al., 2004). Children with CP are able to use the
information originating from the reaching arm, including
the velocity of the arm to adjust the degree of contraction
of the direction-specific postural muscles