SIX MINUTES WALKING IN POLIO SURVIVORS: EFFECTS ON FATIGUE AND WALKING ADAPTABILITY

Objective: To investigate whether 6-min walking is fatiguing for polio survivors, and how fatigue influences their normal and adaptive walking. Design: Cross-sectional study.Patients: Polio survivors (n = 23) with >= 1 fall and/or fear of falling reported in the previous year and healthy individuals (n = 11). Methods: Participants performed 1 normal-walk test and 2 walking-adaptability tests (target step-ping and narrow-beam walking) on an instrumen-ted treadmill at fixed self-selected speed, each test lasting 6 min. Leg-muscle fatigue (leg-muscle acti-vation, measured with surface electromyography), cardiorespiratory fatigue (heart rate, rate of percei-ved exertion), gait and walking-adaptability perfor-mance were assessed. The study compared: (i) the first and last minute per test, (ii) normal and adap-tive walking, and (iii) groups.Results: Leg-muscle activation did not change during normal walking (p > 0.546), but declined over time during adaptive walking, especially in polio survi-vors (p < 0.030). Cardiorespiratory fatigue increased during all tests (p < 0.001), especially in polio survi-vors (p < 0.01), and was higher during adaptive than normal walking (p < 0.007). Target-stepping perfor-mance declined in both groups (p = 0.007), while nar-row-beam walking improved in healthy individuals (p < 0.001) and declined in polio survivors (p < 0.001).Conclusion: Cardiorespiratory fatigue might further degrade walking adaptability, especially among polio survivors during narrow-beam walking. This might increase the risk of falls among polio survivors.

Automated summary

This study investigated the fatigue experienced by polio survivors during 6-min walking and how it influenced their normal and adaptive walking. The results showed that leg-muscle activation declined over time during adaptive walking and cardiorespiratory fatigue increased during all tests, especially in polio survivors. Furthermore, walking adaptability was further degraded by cardiorespiratory fatigue during narrow-beam walking in polio survivors. These findings suggest that fatigue might increase the risk of falls among polio survivors.