The Pediatric Motor Activity Log-Revised: Assessing Real-world Arm Use in Children with Cerebral Palsy

Approximately one-third of children with cerebral palsy (CP) exhibit motor deficits in their more-affected arm (Hagberg, Hagberg, Beckung, & Uvebrant, 2001). Although measures of upper-extremity function in the laboratory or clinic have been available (Gilmore, Sakzewski, & Boyd, 2010), no instruments existed until recently that assess how much such children actually use their more-affected arm in daily life. To address this gap, Taub and co-workers modified a structured interview developed for measuring real-world more-affected arm activity in adults after stroke (Taub, Ramey, DeLuca, & Echols, 2004). In the adult version, termed the Motor Activity Log (MAL), patients rate how they use their more-affected arm for 30 upper-extremity activities in daily life over a specified period (e.g., the past week; Taub et al., 1993; Uswatte & Taub, 2005; Uswatte, E. Taub, D. Morris, K. Light, & P. Thompson, 2006; Uswatte, Taub, Morris, Vignolo, & McCulloch, 2005). In the version for young children, the Pediatric Motor Activity Log (PMAL), primary family caregivers report on their child with upper-extremity hemiparesis (Taub, Ramey, DeLuca, & Echols, 2004). In adult neurorehabilitation, four developments have contributed to the generation of methods for assessing activity of an impaired upper extremity in daily life (Uswatte & Taub, 2005). First, randomized controlled trials (RCTs) supporting the efficacy of Constraint-Induced Movement therapy (CIMT; Taub et al., 1993; Taub et al., 2006; Wolf et al., 2006) for rehabilitating real-world arm use after stroke (reviewed in Langhorne, Coupar, & Pollack, 2009), along with evidence of substantial brain plasticity after this treatment (reviewed in Taub & Uswatte, 2009) have led to a greater emphasis on ameliorating more-affected arm use, as opposed to teaching compensatory strategies (Morris & Taub, 2001; Uswatte, Taub, Morris, Vignolo, & McCulloch, 2005). Second, there has been growing acceptance of the learned nonuse formulation (Taub, 1977, 1980; Taub, Uswatte, Mark, & Morris, 2006), which predicts that after neurological injury the degree of motor recovery measured by laboratory performance tests will frequently overestimate how much an impaired extremity is actually used in daily life. Third, the World Health Organization model of disability has promoted measuring impairment and activity separately (World Health Organization, 2001). Fourth, the rigor with which outcomes are measured has received increasing attention in the rehabilitation sciences (Callahan & Barisa, 2005). Similar considerations in pediatric neurorehabilitation have inspired a parallel interest in measuring more-affected arm activity in children with upper-extremity hemiparesis. In 2009, Wallen, Bundy, Pont, and Ziviani examined the psychometric characteristics of the original version of the PMAL (Taub, Ramey, DeLuca, & Echols, 2004) for measuring this parameter in children with CP between 6 months and 8 years (Wallen, Bundy, Pont, & Ziviani, 2009) when the PMAL was administered as a paper-and-pencil parent report. Wallen and coworkers conducted a Rasch analysis that found the rating scale structure of the PMAL was disordered. Hence, they collapsed the number of PMAL rating scale steps from the original six to three. After re-scoring the PMAL using the 3-step scale, Wallen and coworkers found that, as predicted, children with low levels of manual ability in daily life, as measured by the Manual Abilities Classification System (MACS; Eliasson et al., 2006), had lower PMAL scores than children with high levels. This paper examines the test-retest reliability, convergent validity, and other psychometric characteristics of a revised version of the PMAL in young children with upper-extremity hemiparesis due to CP. The method here departs from the Wallen et al. study by (a) administering the PMAL-R as a structured interview, as originally designed, rather than a correspondent report; (b) scoring the PMAL-R using both the original 6-step and modified 3-step scales; and (c) validating the PMAL-R against an index of everyday activity specific to the more-affected arm rather than a categorization system whose scoring scheme does not take into account which arm is employed, i.e., the MACS.