Quantification of upper extremity function using kinematic analysis.

OBJECTIVE

To illustrate the applicability of motor control analytical techniques to the assessment of upper limb dysfunction in children with ataxia.

DESIGN

Descriptive case series.

SETTING

The study sample was selected from an outpatient pediatric rehabilitation clinic and testing was performed in a research laboratory.

PARTICIPANTS

Four children with upper limb ataxia and seven healthy children were examined. All subjects were recruited on a volunteer basis. Criteria for inclusion (ataxic group) included: (1) age 6 to 15 yrs; (2) ambulatory with assistive devices.

MAIN OUTCOME MEASURES

Quantitative measures of elbow kinematics (movement speed and duration) and spatio-temporal "portraits" of elbow movement during unilateral and bilateral forward reaching movements.

RESULTS

Movements made by ataxic subjects were characterized by lower peak velocities, prolonged durations, and increased variability compared with normal subjects. In the one subject with unilateral ataxia, interlimb coordination was severely disrupted during the performance of coupled, bilateral arm movements. In addition to changes in specific kinematic values (eg, peak velocity), phase plane and angle-angle displacement curves revealed marked spatio-temporal variability throughout the movement, the magnitude of which was correlated with severity of ataxia.

CONCLUSION

The application of the quantitative motor control methods described in this report can provide rehabilitation specialists with a simple yet sensitive means to evaluate treatment and progression of a wide variety of motor disorder conditions. These techniques are particularly well suited to pediatric populations as young as 6 years.