Content » Vol 39, Issue 8

Original report

Oxygen consumption, oxygen cost and physiological cost index in polio survivors: A comparison of walking without orthosis, with an ordinary or a carbon-fibre reinforced plastic knee-ankle-foot orthosis

Kenji Hachisuka, Kenichiro Makino, Futoshi Wada, Satoru Saeki and Nami Yoshimoto

DOI: 10.2340/16501977-0105


Objective: To examine, for polio survivors, whether walking with a carbon-fibre reinforced plastic knee-ankle-foot orthosis (carbon KAFO) is more efficient than walking with an ordinary KAFO or without an orthosis.
Design: Consecutive sample.
Setting: Post-polio clinic, University Hospital of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.
Participants: Eleven polio survivors who had a carbon KAFO prescribed at the post-polio clinic.
Interventions: A carbon KAFO was prescribed, fabricated and inspected.
Main outcome measures: Oxygen consumption, oxygen cost and physiological cost index.
Results: An ordinary KAFO weighed 1403 g (standard deviation(SD) 157 g), whereas a carbon KAFO weighed 992 g (SD 168 g). Subjects walking with a carbon KAFO showed a tendency to increase step length, and to increase speed significantly compared with walking without an orthosis and with an ordinary KAFO (paired t-test, p < 0.05). Oxygen consumption per body weight, oxygen cost (O2 consumption for 1-m walk divided by body weight) and physiological cost index ((heart rate at 3-min walk – heart rate at rest) /speed) were significantly lower than those walking without an orthosis (–16%, –35%, –33%; paired t-test, p < 0.05) and were lower than those walking with an ordinary KAFO (–9%, –14%, –15%; paired t-test, p < 0.05).
Conclusion: The gait efficiency of polio survivors with a carbon KAFO was objectively better than those without an orthosis or with an ordinary KAFO.

Lay Abstract


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