Paraplegic adaptation to assisted-walking: energy expenditure during wheelchair versus orthosis use

Study Design: To study the energy cost of locomotion during ambulation with different orthoses (HIP Guidance Orthosis Orlau Parawalker (PW), n = 4; Re ciprocating Gait Orthosis (RGO), n = 6; RGO + FNS, n = 4). Objectives: Since high energy costs of locomotion have been proposed as a m ajor reason for early rejection of orthotic use, our aims were (a) to evalu ate the impact of functional neuromuscular stimulation (FNS) on energy expe nditure during orthosis-assisted ambulation; (b) to study whether energy ex penditure data can predict the poor long-term patients' compliance and (c) to assess selection criteria for the assignment of the different types of o rthosis. Setting: The study was completed at the Center of Sports Medicine and Cente r of Bioengineering, 'don C. Gnocchi' Foundation, IRCCS, Milan, Italy. Methods: The HR/VO2 relationship and the energy cost of locomotion (C) were studied in 14 patients (lesion level C-7-T-11) during wheelchair (WHCH) us e at various speeds and during locomotion with different orthotic devices. Patients' short- and long-term compliance were assessed by questionnaires e valuating duration of and problems related to orthotic use. Results: (a) In patients using RGO + FNS the slope difference of HR/(V) ove rdot O-2 curves (Delta(sl)HR/ VO2) between WHCH and orthosis was significan tly lower than in other groups (-3 beats in RGO + FNS vs 43 and 52 beats 1( -1) in RGO and PW, respectively); (b) neither C, nor (V) overdot O-2 peak, or Delta(sl)HR/(V) over dot O-2 correlated with orthosis duration of use; ( c) in the RGO + FNS group, C was lower at maximal walking speed, which line arly correlated with maximal WHCH speed. Conclusion: (a) Electrical stimulation seems to improve locomotion, as a co nsequence of hemodynamic effects, but does not decrease energy expenditure, which remains high; (b) the poor long-term compliance to orthosis use cann ot be predicted by the energy expenditure parameters; (c) the subjects who can reach high speeds by WHCH seem to be the most appropriate for RGO + FNS locomotion. Sponsorship: The present study was carried out with the partial financial s upport of the Italian Ministry of Health.