Innovative gait robot for the repetitive practice of floor walking and stair climbing up and down in stroke patients

Hesse et al. Journal of NeuroEngineering and Rehabilitation 2010, 7:30 http://www.jneuroengrehab.com/content/7/1/30 JNER JOURNAL OF NEUROENGINEERING AND REHABILITATION Open Access RESEARCH Innovative gait robot for the repetitive practice of floor walking and stair climbing up and down in stroke patients Research Stefan Hesse*1, Andreas Waldner2,3 and Christopher Tomelleri2 Abstract Background: Stair climbing up and down is an essential part of everyday's mobility. To enable wheelchair-dependent patients the repetitive practice of this task, a novel gait robot, G-EO-Systems (EO, Lat: I walk), based on the end-effector principle, has been designed. The trajectories of the foot plates are freely programmable enabling not only the practice of simulated floor walking but also stair climbing up and down. The article intended to compare lower limb muscle activation patterns of hemiparetic subjects during real floor walking and stairs climbing up, and during the corresponding simulated conditions on the machine, and secondly to demonstrate gait improvement on single case after training on the machine. Methods: The muscle activation pattern of seven lower limb muscles of six hemiparetic patients during free and simulated walking on the floor and stair climbing was measured via dynamic electromyography. A non-ambulatory, sub-acute stroke patient additionally trained on the G-EO-Systems every workday for five weeks. Results: The muscle activation patterns were comparable during the real and simulated conditions, both on the floor and during stair climbing up. Minor differences, concerning the real and simulated floor walking conditions, were a delayed (prolonged) onset (duration) of the thigh muscle activation on the machine across all subjects. Concerning stair climbing conditions, the shank muscle activation was more phasic and timely correct in selected patients on the device. The severely affected subject regained walking and stair climbing ability. Conclusions: The G-EO-Systems is an interesting new option in gait rehabilitation after stroke. The lower limb muscle activation patterns were comparable, a training thus feasible, and the positive case report warrants further clinical studies. Background The annual stroke incidence is approximately 180 per 100.000 inhabitants in the industrialized world [1]. Three months after a stroke, a third of the surviving patients are still wheelchair-dependent, and the gait velocity and endurance are significantly reduced in approximately 80% of the ambulatory patients [2]. Accordingly, the restoration and improvement of walking functions is a primary concern with respect to the aspired social and vocational reintegration. To achieve this goal, a task specific repetitive training seems most promising [3]. The conventional physiother* Correspondence: 1 Medical Park Humboldtmühle Berlin, Department Neurological Rehabilitation Charité - University Medicine, 13507 Berlin, Germany apy instead focuses on strengthening and practicing single movements or various neurofacilitation techniques, but these methods do not stress gait practice. One treatment approach to increase steps number during training sessions is the treadmill training with partial body weight support. [4,5]. However the assignment of human resources for manual assistance in this method is considerable; up to three therapists have to place the paretic limb during the swing phase and to shift the patient's weight onto the stance limb. Consequently, gait machines followed, either applying an exoskeleton [6-9] (e.g. Lokomat, LOPES, ALEX, AutoAmbulator) or an end-effector principle [10-12] (e.g. Gait Trainer GT I, HapticWalker, LokoHelp). The exoskeleton is equipped with programmable drives or pas- Full list of author information is available at the end of the article © 2010 Hesse et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Hesse et al. Journal of NeuroEngineering and Rehabilitation 2010, 7:30 http://www.jneuroengrehab.com/content/7/1/30 sive elements which flex the knees and hips during the swing phase, whereas with the other principle the feet are placed on foot plates, whose trajectories simulate the stance and swing phases. Clinical trials in stroke patients revealed non-equivocal results for the Lokomat [13] and a consistently superior effect for the GT I [14] with respect to the restoration of gait. A head-to-head comparison of the clinical effectiveness between existing machines is missing. An accelerometry-based biomechanical comparison between the Lokomat and the GT I showed comparable mechanical constrains that may alter leg accelerations and decelerations during stance and swing phases [15]. The currently commercially available gait machines (Lokomat, AutoAmbulator, LokoHelp and GT I) are limited to the repetitive exercise of walking on the floor. Stair climbing up and down, however, is an essential part of everyday's mobility, and recent reports indicated that only 5 to 25% of stroke patients can master one floor at their discharge home from early rehabilitation. [16]. To improve the outcome, the patients should frequently practise stair climbing up and down in line with the taskspecific repetitive approach. However the inherent physical effort of the therapists limit the intended intensity, a further burden is the risk of falls on the stairs. The Haptic Walker [17], an end-effector based robot with fully programmable trajectories, was the first device to additionally enable harness-secured patients the repetitive practice of stair climbing up and down without overstressing therapists. The dimensions and the required high voltage, resulting from the goal to achieve a maximum acceleration of 3,5 g during the push-off and a maximum speed of 5 km/h as during natural gait of healthy subjects [18], limited its clinical utility. Accordingly, the present work introduces a newly developed gait robot (G-EO-Systems; EO, latin: I walk) for the treatment of stroke patients (Figure 1). Its specifications included smaller dimensions and an energy supply of 230 V. The main aim of the present study was to compare limb muscle activation patterns of hemiparetic subjects during real and simulated floor walking, and during real and simulated stair climbing up by means of dynamic electromyography. Comparable muscle activation patterns between the real and simulated conditions, and the lack of obviously deviant patterns induced by the gait robot should help to dissipate any fears of the induction of a pathological gait on the machine. The second aim was to demonstrate gait improvement on a single case after a five weeks training with the new machine. Methods Patients Six subacute stroke patients participated. They all (...truncated)