The validity and reliability of the Test of Arm Selective Control for children with cerebral palsy: a prospective cross-sectional study

Abstract

Aim: This study examined the reliability and validity of the Test of Arm Selective Control (TASC) to examine upper extremity selective voluntary motor control in children and adolescents with all types of spastic cerebral palsy (CP).

Method: Fifty-six participants with CP, ranging in age from 5 years 9 months to 18 years 11 months (average 11y 7mo, SD 3y 9mo; 25 males, 31 females), participated in this prospective cross-sectional study. They were evaluated using the TASC and several clinical measures.

Results: TASC and Manual Ability Classification System (r=-0.529, p<0.001), TASC and ABILHAND-Kids (r=0.596, p<0.001), and TASC and affected extremities (r=-0.486, p=0.001) were moderately correlated. There was a weak correlation between the TASC and Gross Motor Function Classification System (r=-0.363, p=0.006) and no correlation between the TASC and age (p=0.366) or rater (p=0.713). Interrater reliability for upper extremity total score (intraclass correlation coefficient [ICC]=0.92-0.94) and upper extremity limb scores (ICC=0.92-0.96) was high for two independent rater groups (p≤0.001). Average time to administer was 16 minutes, 18 seconds.

Interpretation: The TASC is a reliable and valid tool for objective assessment of selective voluntary motor control. Clinically this measure may guide the selection of medical, surgical, or therapy interventions and may improve outcome prognosis.

What this paper adds: The Test of Arm Selective Control (TASC) demonstrates a high degree of reliability and multiple aspects of validity when assessing upper extremity selective control in those with cerebral palsy. The TASC is an upper limb companion to the Selective Control Assessment of the Lower Extremity.

Figure 1. TASC validity

(a) Boxplot of total TASC scores by MACS classification. There was a correlation between MACS level and TASC score (r=−0.529, p<0.001), demonstrating concurrent validity with an activity measure. (b) Boxplot of total TASC scores by limb distribution, or the total number of upper extremities affected according to diagnosis. This was correlated to the total TASC score (r=−0.486, p=0.001). (c) Boxplot of total TASC scores by GMFCS classification. GMFCS level demonstrated a weak correlation to the TASC score (r=−0.362, p=0.006). (d) Discriminate validity between more and less affected limbs in hemiplegia. ^*Indicates significant (p<0.001) difference between the TASC limb score between sides. TASC, Test of Arm Selective Control; MACS, Manual Ability Classification System; CP, cerebral palsy; GMFCS, Gross Motor Functional Classification System.