The effect of impedance-controlled robotic gait training on walking ability and quality in individuals with chronic incomplete spinal cord injury: an explorative study

Abstract

BackgroundThere is increasing interest in the use of robotic gait-training devices in walking rehabilitation of incomplete spinal cord injured (iSCI) individuals. These devices provide promising opportunities to increase the intensity of training and reduce physical demands on therapists. Despite these potential benefits, robotic gait-training devices have not yet demonstrated clear advantages over conventional gait-training approaches, in terms of functional outcomes. This might be due to the reduced active participation and step-to-step variability in most robotic gait-training strategies, when compared to manually assisted therapy. Impedance-controlled devices can increase active participation and step-to-step variability. The aim of this study was to assess the effect of impedance-controlled robotic gait training on walking ability and quality in chronic iSCI individuals.MethodsA group of 10 individuals with chronic iSCI participated in an explorative clinical trial. Participants trained three times a week for eight weeks using an impedance-controlled robotic gait trainer (LOPES: LOwer extremity Powered ExoSkeleton). Primary outcomes were the 10-meter walking test (10MWT), the Walking Index for Spinal Cord Injury (WISCI II), the six-meter walking test (6MWT), the Timed Up and Go test (TUG) and the Lower Extremity Motor Scores (LEMS). Secondary outcomes were spatiotemporal and kinematics measures. All participants were tested before, during, and after training and at 8 weeks follow-up.ResultsParticipants experienced significant improvements in walking speed (0.06 m/s, p = 0.008), distance (29 m, p = 0.005), TUG (3.4 s, p = 0.012), LEMS (3.4, p = 0.017) and WISCI after eight weeks of training with LOPES. At the eight-week follow-up, participants retained the improvements measured at the end of the training period. Significant improvements were also found in spatiotemporal measures and hip range of motion.ConclusionRobotic gait training using an impedance-controlled robot is feasible in gait rehabilitation of chronic iSCI individuals. It leads to improvements in walking ability, muscle strength, and quality of walking. Improvements observed at the end of the training period persisted at the eight-week follow-up. Slower walkers benefit the most from the training protocol and achieve the greatest relative improvement in speed and walking distance.

Increased Brain Sensorimotor Network Activation after Incomplete Spinal Cord Injury

“…A majority of subjects with incomplete SCI regain some degree of ambulatory function; however, gait-related abnormalities are common and thus locomotor training is a key therapeutic target. 46,47 Gait velocity in healthy controls was faster than subjects with incomplete SCI (Table 2). Among subjects with SCI, the fastest walkers had the greatest activation within several brain regions, including left postcentral gyrus and bilateral dorsolateral prefrontal cortex ( Table 3), suggesting that increased activity in these regions Greater time post-injury (see Fig.…”

“…15,23,24,34,54,55 Time is also a major covariate for understanding the effects of SCI on the CNS, 56 but to date few studies have examined its impact on activation of brain motor networks during attempts to move voluntarily. Time post-injury is a key distinguishing factor in relation to locomotor function after incomplete SCI, 47,57 which likely reflects many of the changes that evolve during the years post-SCI, such as altered cardiac function, bone density, muscle changes, and changes in autonomic nervous system function. [58][59][60] In the current study, increased time after incomplete SCI was associated with increased activation in brain regions, including post-central gyrus and SMA (Table 3).…”

Advances in Robotic Gait Training

“…The LOPES I has been evaluated in a small population of chronic stroke survivors with stiff knee gait, for which LOPES therapy increased walking speed and knee flexion [8]. LOPES I training in a small cohort of SCI patients increased their functional outcome measures [9]. Robotic gait trainers can also be used for diagnostic purposes.…”

A Systematic Review of Experimental Strategies Aimed at Improving Motor Function after Acute and Chronic Spinal Cord Injury

“…19 Yazdani and colleagues 23 proposed a combinatorial approach that consisted of cell transplantation of bone-marrow mesenchymal stromal cells and Schwann cells, combined with rehabilitation. The remaining Phase I chronic studies included a rehabilitation study that assessed automated locomotor training using a position-controlled gait-driven orthosis, 41 an impedance-controlled robotic orthosis, 42 and a study that assessed the effects of body weight supported treadmill training combined with electrical stimulation. 43 Segal and associates 44 performed a Phase II study to assess the effects of 4-aminopyridine, a potassium-channel blocker that has been associated with improved axonal conduction, particularly in demyelinated nerve fibers.…”