Kilkens OJ, Dallmeijer AJ, de Witte LP, van der Woude LH, Post MW. The Wheelchair Circuit: construct validity and responsiveness of a test to assess manual wheelchair mobility in persons with spinal cord injury. Arch Phys Med Rehabil 2004;85:424-31. Objective To assess the validity and responsiveness of the Wheelchair Circuit, a test to assess manual wheelchair mobility in persons with spinal cord injury (SCI). Design Longitudinal. Subjects performed the Wheelchair Circuit at the start (T1) and at the end (T3) of inpatient functional rehabilitation. Construct validity and responsiveness were assessed. Setting Eight rehabilitation centers in the Netherlands. Participants Seventy-four subjects with SCI admitted for inpatient rehabilitation. Interventions Not applicable. Main outcome measures The Wheelchair Circuit consists of 8 wheelchair skills and results in 3 test scores: ability, performance time, and physical strain. The construct validity of the Wheelchair Circuit was assessed by testing whether the test scores were significantly related to the subjects' functional status, physical capacity, lesion level, motor completeness of the lesion, and age. To prove the test's responsiveness, it was assessed whether the test scores had significantly improved between T1 and T3. Results For construct validity, 4 of the 5 hypotheses were confirmed. For test responsiveness, all 3 test scores had significantly improved during rehabilitation, and the standardized response mean values ranged from 0.6 to 0.9. Conclusions The Wheelchair Circuit is a valid and responsive instrument with which to measure manual wheelchair mobility in subjects with SCI. © 2004 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.