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

OBJECTIVE: 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. METHODOLOGY: 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. RESULTS: 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). CONCLUSION: 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.