Impairments and activity limitations in subjects with chronic upper-limb complex regional pain syndrome type I.

OBJECTIVE: To determine the degree of impairments and activity limitations and their interrelationship in complex regional pain syndrome type I (CRPS type I). DESIGN: Cross-sectional study interrelating impairments and objectively measured activity limitations. SETTING: Ambulatory and home environment. PARTICIPANTS: Thirty nonacute upper-limb CRPS type I subjects. INTERVENTIONS: Not applicable. Main outcome measures Sensory, motor, and autonomic impairments, as well as activity-limitation outcome measures. The latter were objectively measured with a novel upper-limb activity monitor (based on ambulatory accelerometry). RESULTS: All subjects were impaired to some degree but with a large variability with respect to magnitude. Regarding activity limitations, the involved upper limb was clearly less active (lower intensity and percentage of activity) than the noninvolved side. Impaired active range of motion (adjusted R(2) range, 18%-39%) and grip strength (adjusted R(2) range, 12%-45%) were the most important factors explaining variance in activity limitations. CONCLUSIONS: All subjects were still impaired nearly 3 years after the causative event. The involved upper limb was also clearly less active than the noninvolved side, especially when the subjects were sitting and when the dominant side was involved. The more impairments a subject had, especially motor impairments, the more activity limitations were present.