Energy consumption of locomotion with orthosis versus Parastep-assisted gait: a single case study.

Abstract

Single case study. To evaluate the energy expenditure during ambulation with the Advanced Reciprocating Gait Orthosis (ARGO), with and without functional electrical stimulation (FES), and with the Parastep system in a single subject, in order to avoid the effect of inter-subject variability. The Centre of Sport Medicine and Bioengineering Centre 'Don C Gnocchi' Foundation ONLUS IRCCS, Milano, Italy. A single patient (lesion level T5-T6) was trained specifically for each walking system and was evaluated after each training period. The effects of FES on muscle conditioning, spasticity and bone density were also evaluated. The HR/VO2 relationship and the energy cost of locomotion were measured during wheelchair (WHCH) use, during locomotion with ARGO (with and without FES) and Parastep system at different speeds. The following was observed at the end of the whole training: (a) circumferences of both lower limbs and quadriceps forces were increased, whereas fatigue index was slightly decreased, spasticity and bone density were unchanged; (b) compared to WHCH locomotion, the slope of HR/VO2 curves with ARGO was higher (slope difference=51.1 b 1O2(-1)), with ARGO+FES was similar (slope difference=-5.3 b 1O2(-1)) and with Parastep was smaller (slope difference=-55.6 b 1O2(-1)); (c) HR increased linearly with all locomotion systems, but did not rise above 125 bpm with Parastep; (d) the cost of locomotion was higher with Parastep than with ARGO (with and without FES), tested at each velocity; (e) Parastep appears to be easier to use for the subject. (a) FES can improve ambulation with orthosis, but the cost of locomotion remains very high; (b) the Parastep assisted gait elicits a higher energy expenditure than other orthoses, probably due to the lower speed of locomotion and to the high isometric effort of the stimulated muscles. This work has been partially supported by the Italian Minister of Public Health (Ricerca Finalizzata IRCCS no ICS030.7/RF97.25).