The Relation Between Walking Capacity and Clinical Correlates in Survivors of Chronic Spinal Poliomyelitis

Abstract

Gylfadottir S, Dallimore M, Dean E. The relation between walking capacity and clinical correlates in survivors of chronic spinal poliomyelitis. Objectives To examine (1) common clinical measures that may influence walking performance in the six-minute walk test (6MWT) in people with chronic poliomyelitis and (2) the test-retest reliability of the 6MWT distance, lower-extremity muscle strength, balance, and balance confidence on separate trials. Design A prospective quasi-experimental study. Setting University-based postpolio clinic. Participants Nineteen survivors of poliomyelitis (mean age, 62.2±1.9y; time since polio onset, 54.4±8.79y). Interventions Not applicable. Main Outcome Measures 6MWT distance, rate-pressure product (RPP), Physiological Cost Index (PCI), ratings of perceived exertion (RPE), pain, fatigue, strength, standing balance, balance confidence, limb-length discrepancy, and lung function. Results The 6MWT distance correlated with PCI, pretest pain, lower-extremity muscle strength, balance, balance confidence, corrected leg-length discrepancy, and lung function but not with RPP, RPE, posttest pain, or pretest and posttest fatigue. The PCI correlated with balance confidence and lung function. About 68% of the variance in 6MWT distance was accounted for by balance and pretest pain. The P value was set at .05. Conclusions With stringent standardization of the 6MWT applied to survivors of poliomyelitis (a neuromuscular condition with a musculoskeletal component), reproducibility was high; hence, test validity and interpretation were enhanced. The 6MWT distance was useful in elucidating the relation between impairment and a functional activity—namely, walking—in survivors of poliomyelitis.