Seating orientations and upper extremity function in children with cerebral palsy.

This study was conducted to determine the effect of body orientation on upper extremity function in children and adolescents with cerebral palsy. Thirteen children between ages 8 and 16 and diagnosed as having spastic or athetoid cerebral palsy were placed randomly in different seating orientations (30 degrees, 15 degrees, and 0 degrees of posterior inclination and 15 degrees of anterior inclination). In each seating position, the subject performed an upper extremity activity on cue. The tests were repeated in reverse sequence. Mean performance times were different at all seating orientations for both types of subjects. Performance time was lowest at the 0-degree orientation during the retest for the subjects with spasticity and highest at 15-degree anterior inclination during the retest for the subjects with athetosis. The results of this study show that orientation of the body in space affects upper extremity function and emphasizes the importance of positioning for maximizing upper extremity function.

Nondominant arm restraint and dominant arm function in a child with athetoid cerebral palsy: electromyographic and functional evaluation.

This single case study was designed to determine the effect of restraining the nondominant arm on the function of the dominant arm of a child with athetoid cerebral palsy. Performance time of shoulder horizontal adduction was computed with and without the restraint. Electromyographic (EMG) activity of selected muscles was simultaneously monitored by surface electrodes. Performance time was less when the arm restraint was applied. Generally, tonic and phasic EMG activity decreased in all muscles monitored. The results show that upper extremity motor function improved in the dominant arm when the nondominant arm was restrained and that myoelectric activity was not adversely affected when the restraint was applied.

Effects of body orientation in space on tonic muscle activity of patients with cerebral palsy.

This study was designed to determine whether tonic activity of selected muscles of patients with cerebral palsy changed in response to changes in orientation of the body in space. Surface electrodes measured electromyographic activity of the low-back extensor, hip adductor and ankle plantar-flexor muscles when the body was at 0 degree (upright) and 30 degrees (recline) relative to the vertical. Muscle activity did change in response to body orientation, and was less in the upright position.

Effect of adaptive seating on pulmonary function of children with cerebral palsy.

The vital capacity (VC), forced expiratory volume in one second (FEV1) and expiratory time (ET) of eight cerebral-palsied children aged between five and 12 years was measured, when seated in a regular sling-type wheelchair and in an adaptive seating system. The results showed a 57.7 per cent increase in VC, a 51.6 per cent increase in FEV1 as a percentage of VC, and a 55 per cent increase in ET in the adaptive seating system compared with the standard wheelchair. These results have important implications for speech, sitting for prolonged periods and prevention of hypoxia and pulmonary hypertension.

Electromyographic and force patterns of cerebral palsy patients with windblown hip deformity.

The electromyographic activity and the forces around the hip were measured in resting, neutral, and 25 degrees abduction in 13 individuals with spastic quadriplegia and windblown deformity. A direct correlation was found between abduction force and myoelectric activity of the abductors. In the adducted hip, there was sustained activity of the adductors while the activity in the abductors was minimal in all positions. In the abducted hip, there was electrical activity in both abductors and adductors in all positions except 25 degrees abduction when only the adductors were active. The results suggest that early detection of potentially progressive windblown hips in children with cerebral palsy may be achieved by careful assessment of hip range of motion, recognition of spasticity in abductors, and the presence of a "pseudo-Galleazzi sign."

Mechanical and anatomic hip flexion angles on seating children with cerebral palsy.

This study measured anatomic hip flexion angles (AHFAs) at specific and known mechanical hip flexion angles (MHFAs) (ie, seat-to-back angles) in order to determine the relationship between the two in the seated position. Six able-bodied children and 12 children with cerebral palsy were placed in eight different MHFA positions while AHFA was simultaneously measured. It was found that, although related, the hip flexion angle and the angle between the backrest and seat surface are not equal in most seated positions. The difference between AHFA and MHFA was greater in the children with cerebral palsy than in the able-bodied. The hip flexion angle of the child in the seated position should not be described as the angle between the backrest and seat surface or the angle of inclination of the backrest.

Electromyographic investigation of extensor activity in cerebral-palsied children in different seating positions.

This study was designed to determine whether tonic myoelectric activity of low-back extensors of spastic cerebral-palsied children changed in response to changes in seating position, and if so, which position was coincident with the least extensor activity. Using two pairs of surface electrodes, the electrical activity of the lumbar erector spinae muscles was monitored in seven combinations of backrest inclinations (75 degrees, 90 degrees, 105 degrees and 120 degrees) and seat surface elevations (0 degrees and 15 degrees). Off-line analysis of action potential counts per second of recorded electromyographic signals showed that electrical activity was least when the seat surface elevation was 0 degrees and the backrest inclination 75 degrees. The results showed that differences existed in the activity of the low-back extensors in the seating positions that were assessed.