Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK
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PublicationMuscle activation of stroke patients during stair climbing in robot assisted gait training( 2008)
;Hussein, S. ;Schmidt, H. ;Volkmar, M. ;Krüger, J.Hesse, S.For central nervous system (CNS) impaired patients, e.g. after stroke, the achievement of an independent, stable gait function and endurance in walking is essential for independent mobility in daily life. Modern concepts of rehabilitation favor a task specific repetitive training, that facilitates natural motion and muscle activation patterns, i.e. in addition to commonly practiced floor walking other gait motions of daily living (ADL), such as stair climbing, should be trained. In gait rehabilitation of severely affected non-ambulatory patients, a guided training must be applied as no or only little voluntary motor control is left in the affected side. The rehabilitation robot HapticWalker is the first device that allows for robot assisted guided training of arbitrary foot trajectories, e.g. also stair climbing. The goal of this study was to assess the effect of guided training in stair climbing condition on the HapticWalker on the movement and muscle activation patterns of stroke patients. Generally rhythmic and phasic muscle activation patterns were observed, which is an important factor in gait rehabilitation. The training of stair climbing condition on the HapticWalker also facilitated body weight shift in all patients and proper activation of weight bearing muscles. The HapticWalker currently lacks a lateral hip guidance facility, hence individual differences in the ability of controlling hip movement and body weight shift depending on the level of gait ability were observed.
PublicationMuscle activation patterns of healthy subjects during floor walking and stair climbing on an end-effector-based gait rehabilitation robot( 2007)
;Schmidt, H. ;Volkmar, M. ;Werner, C. ;Helmich, I. ;Piorko, F. ;Krüger, J.Hesse, S.A major criterion for the application of rehabilitation robots in gait therapy is the question to what extent the machine is able to facilitate physiologically correct muscle activation patters in the patients leg muscles in order to achieve an optimal gait training effect The EMG data presented in this paper is based on intermediate results of a study with 8 healthy subjects (5 male, 3 female) to evaluate the end-effector based gait rehabilitation robot HapticWalker in position controlled mode. The study investigated two different walking trajectories (floor, upstairs) at three different cadences (45, 60, 90 steps/min) in three different modes (free walking, HapticWalker with vertical CoM motion, HapticWalker without vertical CoM motion). Results show that muscle EMGs measured from all relevant leg muscles have the same phasic and rhythmic muscle activation patterns on the HapticWalker as with free walking. Even though there are differences in patterns of dedicated muscles, the authors observed reduced amplitudes and slightly delayed activation on the HapticWalker compared to free walking. No differences in EMGs were observed between the two different HapticWalker modes (with vertical CoM motion, cancelled CoM motion), which might eliminate the need for an active trunk suspension system in the latter case. A passive patient lifter would significantly reduce the complexity of the machine construction, all advanced training modes (e.g. dynamic body weight reduction) could then be accomplished via compliant behavior of the freely programmable footplates. Numerous EMG measurements with healthy subjects and non-ambulatory stroke patients were performed on the predecessing electromechanical Gait Trainer GT I and showed that physiologically relevant findings from healthy subjects (e.g. correct phasic muscle activation) can be transferred to a certain extent to stroke patients, but nevertheless studies with stroke patients on the robotic gait trainer HapticWalke. Entnommen aus TEMA
PublicationGait machines and robots to support motor rehabilitation after stroke( 2007)
;Schmidt, H. ;Hussein, S. ;Werner, C. ;Bernhardt, R. ;Hesse, S.Krüger, J.The group at Klinik Berlin/Charite University Hospital in Berlin, Germany, began studies to promote motor recovery after stroke in the early 1990s. Following the introduction of treadmill training with partial body-weight support, the group designed an electromechanical gait trainer, GT I, based on movable foot plates that relieve therapist effort (e.g., when assisting the movement of the paretic limbs) and intensify patient gait training (GT). Preliminary results of a recent multicenter trial of 155 acute stroke patients showed that the GT I effectively promotes gait ability and competence in activities of daily living. The experimental group received 20 min of GT and 25 min of physiotherapy (PT) and the control group received 45 min of PT every day for 4 weeks. The laboratory's next step was the HapticWalker, a robotic walking simulator with freely programmable foot plates which was designed and built in close collaboration with the Fraunhofer Institute IPK. On this machine patients can, for example, additionally train for stair climbing and perturbations. The foot plates can be operated in full guidance or compliance control modes, thus reducing foot support according to the patient's learning success. Entnommen aus TEMA