Energy expenditure of walking for adult patients with spinal cord lesions using the reciprocating gait orthosis and functional electrical stimulation

Abstract

A major factor influencing compliance with walking orthoses following spinal cord damage, is the energy requirement associated with them. We compared ambulatory energy expenditure in subjects using the reciprocating gait orthosis (RGO) with and without functional electrical stimulation (FES) of the thigh muscles at self selected walking speeds. Five adult subjects (median age 34 years, range 24 -37) with spinal cord lesions ranging from C2 (incomplete) to T6 volunteered to participate in this study. All subjects were successful RGO users (median use 5.7 years, range 4. 1-7.3). Walking speed (m/s), ambulatory energy consumption (J/kg/s) and energy cost (J Ikg/m) were derived from oxygen uptake determined using the Douglas bag technique. We anticipated that subjects walking with FES would either: (a) walk at the same speed but reduce their energy cost or (b) increase their walking speed for the same (or less) energy cost. Walking speed and energy cost remained unchanged in one subject. One subject increased his walking speed by 14.0% and increased his energy consumption by 8.4%. His energy cost remained unchanged. Three subjects increased their walking speeds (by 12.4, 12.7 and 6.8%), energy consumption (by 25.9, 20.4 and 18.4% respectively) and energy cost (by 11.6, 6.8 and 10.5% respectively). We did not find a substantial benefit, in terms of energy expenditure, from the hybrid system when walking continuously for 5 min. We suggest that the hybrid system may be of greater benefit during prolonged walking, although other limitations, inherent in the RGO itself, may prevent an increase in compliance. Repetition of walking speed tests supported the reliability of our results. Tests on comparably aged, able bodied subjects showed that an increase in energy cost of up to 5.8% was within the biological variability of the subject and the error of the methodology.

Prediction of gait outcome with the knee–ankle–foot orthosis with medial hip joint in patients with spinal cord injuries: a study using recursive partitioning analysis

“…17 The walking speed of the subjects in this study was almost comparable with that of patients using an HKAFO such as RGO. 17,25,26 We believe, therefore, that the subjects whose final outcome of gait was predicted in this study belonged to a typical group of patients who underwent appropriate exercise and acquired appropriate ability.…”

“…18,19 Walking speed is higher and energy expenditure is lower in the former than in the latter. 24,26,27 The lower the neurological level, the more easily can patients acquire walking ability with orthoses. 17,18,20 As this seems to hold true for MSH-KAFO, it is not surprising that the neurological level was extracted as a main branching factor in recursive partitioning in this study.…”

Exercise Intensity during Treadmill Walking with Gait-Patterned FES among Patients with Incomplete Spinal Cord Injury: Case Series

“…On average, the speed of locomotion was higher during walking with FES as compared to walking without FES, while the oxygen consumption was reduced somewhat. Sykes et al investigated energy consumption and energy cost during walking, using the reciprocating gait orthosis (RGO) with FES (surface stimulation of quadriceps and hamstrings) [21]. In their study, walking speed and energy cost remained unchanged in one subject, whereas another subject increased his walking speed by 14.0%, increased his energy consumption by 8.4%, and his energy cost remained unchanged.…”

“…GP-FES stimulates both leg flexor and extensor muscles in a physiological pattern for a longer portion of the gait cycle. Therefore, it is likely that gait training with GP-FES is capable of assisting individuals with SCI to increase their oxygen consumption, by increasing their leg muscle activation, as shown in prior studies describing oxygen consumption during walking with FES (but not GP-FES) [21].The purpose of this case series was to determine the feasibility of increasing the cardiopulmonary exercise intensity during walking with GP-FES among individuals with chronic incomplete SCI.…”

Electrical Stimulation and Motor Recovery

“…Called neuroprostheses (25,193), these devices often are designed to correct specific deficits, such as foot drop (27,217,245) and hand grasp weakness (47,249,267). Other devices, such as the Parastep (71), use multichannel stimulators to activate leg muscles for standing and walking (184,238,239,242).FES implies electrical stimuli applied to skin surface over muscles, usually activating local nerves innervating muscle. For this reason, FES cannot be used to stimulate denervated muscles (79).…”