A behavioral observation system for quantifying arm activity in daily life after stroke.

Several bodies of evidence suggest that under certain conditions actual use of an upper-extremity departs markedly from the severity of impairment after neurological injury (e.g., see review by Uswatte & Taub, 2005) Animal studies directed by E. Taub have shown that monkeys that have had surgery to abolish all sensation from a forelimb typically never use this limb again even though they recover considerable ability to control movements of the deafferented limb 8–24 weeks after surgery. The monkeys do not use their deafferented forelimb even though they can 8–24 weeks after surgery because when the animals attempt to use that forelimb soon after surgery they still do not have sufficient motor control to manipulate objects or support their weight successfully. These failed attempts punish use of the deafferented forelimb and suppress its use permanently unless the “learned nonuse” is counterconditioned using some simple behavioral methods. Cross-sectional studies of hemiparetic arm function in stroke and traumatic brain injury (TBI) survivors with mild to moderate motor impairment show differences between severity of paresis and actual use of the paretic arm in daily life that are consistent with the type of excess motor deficit present in the deafferented monkey model. Clinical trials of Constraint-Induced Movement therapy (CI therapy) show that after CI therapy stroke and TBI survivors exhibit much larger gains in real-world use of the hemiparetic arm than in motor ability. This evidence, along with biopsychosocial models of disability such as the diagnostic system from the World Health Organization (2001), have led to interest in measuring impairment and real-world activity separately. The new measures of real-world activity include structured interviews that assess real-world arm use, such as the Motor Activity Log (E. Taub et al., 1993; Uswatte, Taub, Morris, Light, & Thompson, 2006; Uswatte, Taub, Morris, Vignolo, & McCulloch, 2005), and physical sensors that continuously monitor arm movement during daily life, such as accelerometers (Schasfoort, Bussman, Zandbergen, & Stam, 2003; Uswatte et al., 2005; Uswatte et al., 2000). Their validity has been demonstrated by examining how they are correlated with each other (e.g., Uswatte, Taub, Morris, Vignolo, & McCulloch, 2005) and with measures of impairment (e.g., van der Lee, Beckerman, Knol, de Vet, & Bouter, 2004). (The latter approach is flawed given the evidence cited above for dissociation between real-world use and severity of impairment under certain conditions; Uswatte & Taub, 2005.) A "gold standard" against which these real-world measures can be compared has not been available. This paper presents inter-rater reliability and convergent validity for the Functional Arm Activity Behavioral Observation System (FAABOS), which quantifies amount of more-impaired arm function in daily life from random samples of video recordings from stroke and TBI survivors’ homes. Results are presented from two separate groups of participants (Study 1 and 2), who were videotaped in different contexts and rated by different sets of observers. This instrument, which directly and objectively assesses the construct of interest, might serve as such a gold standard, and as a measure of treatment outcome and functional status on its own.