INFLUENCE OF DIFFERENT SITTING POSITIONS AND ABDUCTION ORTHOSES ON LEG MUSCLE-ACTIVITY IN CHILDREN WITH CEREBRAL-PALSY

A surface electromyogram (EMG) was recorded from four leg muscles to m easure the effects of various seat inclinations and an abduction ortho sis on eight children with cerebral palsy and controls during performa nce of an upper-extremity task and while listening to a story. EMG res ponses were lowest in the forward-leaning and horizontal positions wit h the abduction orthosis, and highest in reclined and horizontal posit ions without the orthosis for both groups of children during the perfo rmance of an upper-extremity task. While listening to a story, there w as no median EMG activity in any muscles of the controls, but there we re wide variations in those of the children with cerebral palsy. The r esults indicate that the use of an abduction orthosis and horizontal a nd forward-leaning seats decrease lower-extremity muscle activity, and so it is possible that it might also improve upper-extremity function .