The Physiological Cost Index of Walking with an Isocentric Reciprocating Gait Orthosis Among Patients with T12–L1 Spinal Cord Injury

Abstract

The objective of this study was to compare the Physiological Cost Index of walking with a reciprocating gait orthosis to that of walking with bilateral knee-ankle-foot orthoses (KAFOs) by subjects with paraplegia resulting from T(12) - L(1) spinal cord lesions. Six chronic paraplegic subjects who had T(12) - L(1) spinal cord lesions and who previously wore bilateral KAFOs were recruited. Each subject was fitted with an isocentric reciprocating gait orthosis (IRGO) and received a standardized training program. Subjects were then asked to walk using the two orthotic devices along a 40 m rectangular pathway at a speed that was comfortable for them. The walking speed was measured using a stop watch, and a Polar Heart Rate Monitor was used to measure the heart rate of the subjects. The Physiological Cost Index (PCI) was calculated for comparison. Ambulation using the IRGO (10.46 +/- 2.00 m/min) was significantly faster (p = 0.009) than ambulation using the bilateral KAFOs (5.51 +/- 4.30 m/min). The PCI demonstrated when walking with the IRGO (2.85 +/- 0.77 beats/m) was significantly lower (p = 0.0306) than that of the bilateral KAFOs (6.77 +/- 3.28 beats/m). Paraplegic patients with T(12) - L(1) spinal cord lesions walk faster and more efficiently using the isocentric reciprocating gait orthosis as compared to using the bilateral KAFOs.