Now showing 1 - 7 of 7
  • Publication
    Muscle coordination in healthy subjects during floor walking and stair climbing in robot assisted gait training
    ( 2008)
    Hussein, S.
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    Schmidt, H.
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    Volkmar, M.
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    Werner, C.
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    Helmich, I.
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    Pioko, F.
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    Krüger, J.
    ;
    Hesse, S.
    The aim of gait rehabilitation is a restoration of an independent gait and improvement of daily life walking functions. Therefore the specific patterns, that are to be relearned, must be practiced to stimulate the learning process of the central nervous system (CNS). The Walking Simulator HapticWalker allows for the training of arbitrary gait trajectories of daily life. To evaluate the quality of the training a total of 9 subjects were investigated during free floor walking and stair climbing and during the same tasks in two different training modes on the HapticWalker: 1) with and 2) without vertical center of mass (CoM) motion. Electromyograms (EMG) of 8 gait relevant muscles were measured and muscle activation was compared for the various training modes. Besides the muscle activation as an indicator for the quality of rehabilitation training the study investigates if a cancellation of the vertical CoM movement by adaption of the footplate trajectory is feasible i.e. the muscle activation patterns for the two training modes on the HapticWalker agree. Results show no significant differences in activation timing between the training modes. This indicates the feasibility of using a passive patient suspension and emulate the vertical CoM motion by trajectory adaption of the footplates. The muscle activation timing during HapticWalker training shows important characteristics observed in physiological free walking though a few differences can still remain.
  • Publication
    Gait rehabilitation machines based on programmable footplates
    ( 2007)
    Schmidt, H.
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    Werner, C.
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    Bernhardt, R.
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    Hesse, S.
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    Krüger, J.
    Background: Gait restoration is an integral part of rehabilitation of brain lesioned patients. Modern concepts favour a task-specific repetitive approach, i.e. who wants to regain walking has to walk, while tone-inhibiting and gait preparatory manoeuvres had dominated therapy before. Following the first mobilization out of the bed, the wheelchair-bound patient should have the possibility to practise complex gait cycles as soon as possible. Steps in this direction were treadmill training with partial body weight support and most recently gait machines enabling the repetitive training of even surface gait and even of stair climbing. Results: With treadmill training harness-secured and partially relieved wheelchair-mobilised patients could practise up to 1000 steps per session for the first time. Controlled trials in stroke and SCI patients, however, failed to show a superior result when compared to walking exercise on the floor. Most likely explanation was the effort for the therapists, e. g. manually setting the paretic limbs during the swing phase resulting in a too little gait intensity. The next steps were gait machines, either consisting of a powered exoskeleton and a treadmill (Lokomat, AutoAmbulator) or an electromechanical solution with the harness secured patient placed on movable foot plates (Gait Trainer GT I). For the latter, a large multi-centre trial with 155 non-ambulatory stroke patients (DEGAS) revealed a superior gait ability and competence in basic activities of living in the experimental group. The HapticWalker continued the end effector concept of movable foot plates, now fully programmable and equipped with 6 DOF force sensors. This device for the first time enables training of arbitrary walking situations, hence not only the simulation of floor walking but also for example of stair climbing and perturbations. Conclusion: Locomotor therapy is a fascinating new tool in rehabilitation, which is in line with modern principles of motor relearning promoting a task-specific repetitive approach. Sophisticated technical developments and positive randomized controlled trials form the basis of a growing acceptance worldwide to the benefits or our patients.
  • Publication
    Muscle activation patterns of healthy subjects during floor walking and stair climbing on an end-effector based gait rehabilitation robot
    ( 2007)
    Hussein, H.
    ;
    Schmidt, H.
    ;
    Volkmar, M.
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    Werner, C.
    ;
    Helmich, I.
    ;
    Piorko, F.
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    Krüger, J.
    ;
    Hesse, S.
  • Publication
    Muscle 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
  • Publication
    Gait machines and robots to support motor rehabilitation after stroke
    ( 2007)
    Schmidt, H.
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    Hussein, S.
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    Werner, C.
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    Bernhardt, R.
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    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
  • Publication
    Roboterunterstütztes Treppensteigen in der neurologischen Gangrehabilitation
    ( 2007)
    Hussein, S.
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    Radmer, J.
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    Volkmar, M.
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    Werner, C.
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    Schmidt, H.
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    Krüger, J.
    ;
    Hesse, S.
  • Publication
    Machines and robots to support motor rehabilitation after stroke
    ( 2007)
    Schmidt, H.
    ;
    Werner, C.
    ;
    Bernhardt, R.
    ;
    Hesse, S.
    ;
    Krüger, J.