Reliability And Validity Of The 6-minute Wheelchair Propulsion Test

Abstract

Wheelchair mobility and fitness are essential after spinal cord injury (SCI). A wheelchair mobility capacity field test shows promise for assessing mobility/fitness, although reliability/validity of the 6-minute propulsion test (6MPT) are untested. PURPOSE: To assess 6MPT test-retest reliability, criterion validity as a fitness test, and ability to discriminate between people with tetraplegia (TP) and paraplegia (PP). METHODS: 26 participants (TP=11, PP=15) underwent 3 assessments on non-consecutive days. Assessment 1; A peak armcrank test with open-circuit spirometry (ACEpeak). Assessments 2 and 3; The 6MPT in accordance with American Thoracic Society standards. Total distance (6MPTdist) and peak oxygen consumption (6MPTpeak) were tested on an indoor course. Outcomes were: 6MPTdist (m), 6MPTpeak (ml.min-1), and ACEpeak (ml.min-1). Intra-class correlation (ICC) assessed 6MPTdist and 6MPTpeak reliabilities. Criterion validity examined ACEpeak and the first 6MPTpeak. ICC values ≥0.75 established excellent reliability/validity. Mann-Whitney U compared PP and TP 6MPTdist and 6MPTpeak (α=0.05). RESULTS: Data (mean +/- s.d.) are shown (Table 1). ICCs for 6MPTdist and 6MPTpeak reliability were >0.95. The ICC for 6MPTpeak and ACEpeak was 0.85, and Mann-Whitney U discriminated PP and TP for 6MPTdist and 6MPTpeak. (all p's< 0.05) CONCLUSIONS: Reliability, criterion, and discriminant validity of the 6MPT were demonstrated for persons with TP and PP. No significant difference was observed between 6MPTdist and 6MPTpeak, or 6MPTpeak and ACEpeak performance. 6MPTpeak achieved during the 6MPT is comparable to the criterion condition. The 6MPT satisfies criteria for a reliable/valid field test of wheelchair mobility/fitness.Table