Stefan Hesse

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

BackgroundStair climbing up and down is an essential part of everydays 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.MethodsThe 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.ResultsThe 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.ConclusionsThe 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.

Effect on arm function and cost of robot-assisted group therapy in subacute patients with stroke and a moderately to severely affected arm: a randomized controlled trial

Objective: To evaluate the effectiveness and efficiency of robot-assisted arm group therapy (RAGT) versus individual arm therapy (IAT) to restore motor function in the moderately to severely affected patient after stroke. Design: Single blind randomized controlled trial. Setting: Two in-patient neurological rehabilitation centers. Participants: Fifty first time subacute patients with stroke and a non-functional hand. Intervention: The patients practiced either 30 minutes of RAGT + 30 minutes of IAT (group A) or 2x30 minutes of IAT (group B), per workday for four weeks. The RAGT consisted of six workstations enabling repetitive practice of finger, wrist, forearm and shoulder movements. Patients practiced according to their impairment level on at least two workstations per session. The IAT followed the Motor Relearning Programme, enriched by elements of the impairment-oriented training. Main outcome measure: Changes of the Fugl Meyer Score (FM, 0-66) between baseline and after 4 weeks, incremental cost effectiveness. Results: Patients were homogeneous at study onset. All patients improved their upper limb motor function over time, but there were no between group differences. The initial (terminal) FM scores were 14.6±9.4 (25.7±16.5) in group A and 16.5±9.8 (31.1±19.1) in group B. The treatment of a single patient with RAGT cost 4.15 €, compared to 10.00 € for a patient to receive IAT. Conclusion: RAGT in combination with IAT was equally effective as a double session of IAT regarding the restoration of upper limb motor functions in moderate to severely affected subacute patients with stroke. The treatment costs for RAGT were less.

An early botulinum toxin A treatment in subacute stroke patients may prevent a disabling finger flexor stiffness six months later: a randomized controlled trial

Objective: The study asked whether an early botulinum toxin A (BTX-A) injection in subacute stroke patients may prevent a disabling finger flexor stiffness six months later. Design: Single-blind, randomized pilot study. Setting: Inpatient rehabilitation centre. Subjects: Eighteen stroke patients, interval 4–6 weeks, non-functional arm, Fugl-Meyer arm score (0–66) <20, beginning elevated finger flexor tone, randomly allocated to group A or B. Interventions: In group A patients 150 units BTX-A (Xeomin) injected into the deep and superficial finger (100 units) and wrist flexors (50 units), no injection in group B patients. Comprehensive rehabilitation in both groups. Main measures: Primary variable was the Modified Ashworth Scale score (0–5) of the finger flexors; secondary variables were whole arm muscle tone with REPAS (a summary rating scale for resistance to passive movement), its motor control with the Fugl-Meyer arm score, and a disability scale, blindly assessed at T0 (start), T1 (four weeks) and T6 (six months). Results: Homogeneous groups at T0. Significantly less finger flexor stiffness in the BTX-A group at T1 and T6, the mean (SD) Modified Ashworth Scale scores in group A (B) were: 1.7 ± 0.5 (1.6 ± 0.5) at T0; 0.4 ± 0.5 (1.9 ± 0.7) at T1; and 1.4 ± 0.7 (2.4 ± 0.9) at T6. Among the secondary measures, the disability score, namely the items pain and passive nail trimming, was lower in group A at T1 and T6. Conclusions: The results indicate an effect of early BTX-A injection on finger flexor stiffness six months later, presumably attributable to a reduced contracture development. Effect size calculation suggests inclusion of at least 17 patients per group excluding drop-outs in a warranted placebo-controlled trial.

Effect of different training modes on ground reaction forces during robot assisted floor walking and stair climbing

The HapticWalker is a robotic walking simulator for neurological gait rehabilitation. The device is based on the end-effector principle, i.e. the patients feet are fixed on two footplates, his trunk is secured via a suspension harness. The footplates (end-effectors) of the robot guide the feet of the patient on freely programmable trajectories. Currently two different training modes are provided for each foot trajectory on the HapticWalker. Firstly training trajectories based on real motion capture data can be used. Secondly the vertical center of mass (CoM) motion can be incorporated into the foot trajectory. The latter method leaves the absolute position of the CoM constant, while the relative movement between CoM and feet remains the same as in free walking. Thereby the vertical CoM motion can be actively supported by using a fixed passive suspension, any type of controlled body weight support will then be accomplished via force controlled footplates. To characterize the training on the machine in position controlled mode, muscle activities as well as ground reaction force data of healthy subjects were collected. This article presents preliminary results from the investigation of ground reaction force data of healthy subjects. Therefore data of 10 healthy subjects was used to compare HapticWalker training modes vs. free walking on level ground and upstairs without any assistive devices and the aforementioned two HapticWalker training modes against each other. Amplitude and timing of force peaks during heel strike, foot flat and push off in vertical ground reaction forces were used for the assessment. In spite of a footplate, which does not provide a separate metatarsal joint for relative motion between fore and hind foot, during heel strike and push off the known characteristic peaks at the beginning and the end of the stance phase can be clearly distinguished. Though compared to free walking a slower and premature rise and slower decline of ground reaction forces can be seen due to the stiff guidance of the feet in position controlled mode. No significant differences appeared between the two described HapticWalker training modes.

Comparison of an intermittent high-intensity vs continuous low-intensity physiotherapy service over 12 months in community-dwelling people with stroke: a randomized trial

Objective: This study compared two modes of physiotherapy service over 12 months in community-dwelling people with stroke, either following a train—wait train paradigm by providing bouts of intense physiotherapy, or a continuous less intense programme. Design: Randomized trial. Setting: Community-dwelling people with stroke. Interventions: Fifty patients, first-time stroke, discharged home, following inpatient rehabilitation, allocated to two groups, A and B. Over 12 months, Group A (n = 25) received three two-month blocks of therapy at home, each block contained four 30 to 45 minute sessions per week, totalling 96 sessions. Group B (n = 25) continuously received two 30 to 45 minute sessions per week, totalling 104 sessions. Main outcome measures: Primary Rivermead Mobility Index (0—15), secondary upper- and lower-limb motor functions, Activities of Daily Living competence, tone and number of falls. Results: Both groups were comparable at onset, the mean age in Group A (B) was 62.4 (61.9) years. A and B patients equally improved functions over time, between group differences did not occur. The initial (terminal) Rivermead Mobility Index was 9.4 ± 2.8 (12.2 ± 2.1) in Group A, and 8.5 ± 3.5 (11.2 ± 2.7) in Group B. More Group B patients fell seriously (7 versus 1). Conclusions: The intermittent high-intensity and continuous low-intensity therapy protocols were equally effective, the sheer intensity seems more important than the time-mode of application. The relatively young patients functionally improved in the first year after stroke, the reduced risk of serious falls in the intermittent high-intensity group should be validated.

Physical fitness training in Subacute Stroke (PHYS-STROKE) - study protocol for a randomised controlled trial

BackgroundGiven the rising number of strokes worldwide, and the large number of individuals left with disabilities after stroke, novel strategies to reduce disability, increase functions in the motor and the cognitive domains, and improve quality of life are of major importance. Physical activity is a promising intervention to address these challenges but, as yet, there is no study demonstrating definite outcomes. Our objective is to assess whether additional treatment in the form of physical fitness-based training for patients early after stroke will provide benefits in terms of functional outcomes, in particular gait speed and the Barthel Index (co-primary outcome measures) reflecting activities of daily living (ADL). We will gather secondary functional outcomes as well as mechanistic parameters in an exploratory approach.Methods/DesignOur phase III randomised controlled trial will recruit 215 adults with moderate to severe limitations of walking and ADL 5 to 45xa0days after stroke onset. Participants will be stratified for the prognostic variables of “centre”, “age”, and “stroke severity”, and randomly assigned to one of two groups. The interventional group receives physical fitness training delivered as supported or unsupported treadmill training (cardiovascular active aerobic training; five times per week, over 4xa0weeks; each session 50xa0minutes; total of 20 additional physical fitness training sessions) in addition to standard rehabilitation treatment. The control intervention consists of relaxation sessions (non-cardiovascular active; five times per week week, over 4xa0weeks; each session 50xa0minutes) in addition to standard rehabilitation treatment. Co-primary efficacy endpoints will be gait speed (in m/s, 10xa0m walk) and the Barthel Index (100 points total) at 3xa0months post-stroke, compared to baseline measurements. Secondary outcomes include standard measures of quality of life, sleep and mood, cognition, arm function, maximal oxygen uptake, and cardiovascular risk factors including blood pressure, pulse, waist-to-hip ratio, markers of inflammation, immunity and the insulin-glucose pathway, lipid profile, and others.DiscussionThe goal of this endpoint-blinded, phase III randomised controlled trial is to provide evidence to guide post-stroke physical fitness-based rehabilitation programmes, and to elucidate the mechanisms underlying this intervention.Trial registrationRegistered in ClinicalTrials.gov with the Identifier NCT01953549.

Adaptive locomotor training on an end-effector gait robot: Evaluation of the ground reaction forces in different training conditions

The main goal of robotic gait rehabilitation is the restoration of independent gait. To achieve this goal different and specific patterns have to be practiced intensively in order to stimulate the learning process of the central nervous system. The gait robot G-EO Systems was designed to allow the repetitive practice of floor walking, stair climbing and stair descending. A novel control strategy allows training in adaptive mode. The force interactions between the foot and the ground were analyzed on 8 healthy volunteers in three different conditions: real floor walking on a treadmill, floor walking on the gait robot in passive mode, floor walking on the gait robot in adaptive mode. The ground reaction forces were measured by a Computer Dyno Graphy (CDG) analysis system. The results show different intensities of the ground reaction force across all of the three conditions. The intensities of force interactions during the adaptive training mode are comparable to the real walking on the treadmill. Slight deviations still occur in regard to the timing pattern of the forces. The adaptive control strategy comes closer to the physiological swing phase than the passive mode and seems to be a promising option for the treatment of gait disorders. Clinical trials will validate the efficacy of this new option in locomotor therapy on the patients.

Botulinum toxin-induced focal paresis in mice is unaffected by muscle activity

To test the hypothesis that the efficacy of botulinum toxin depends on the activity of the neuromuscular junction, we developed an in vivo paradigm to determine the degree and duration of low‐dose botulinum toxin‐induced focal paresis in mice.

Accurate quantification of tetanus neurotoxin-induced focal spasticity in mice using complex running wheels

Tetanus neurotoxin (TeNT) enhances activity of motoneurons by blocking spinal inhibitory interneurons. Based on this pathomechanism, we propose that low-dosage intramuscular injections of TeNT could serve as a specific treatment for central paretic muscles. However in vivo TeNT research is restricted because of the fear of triggering widespread muscle spasms. In addition, no reliable test to measure the in vivo toxicity of low-dosage TeNT is available. We introduce a novel wheel running-based paradigm with mice to quantify functional effects and thus the toxicity of low-dosage TeNT in vivo. We accustomed three groups of wildtype mice (n=14) to using a complex running wheel with irregularly spaced crossbars. Each group received an injection with a different low-dosage of TeNT (0.15 ng, 0.1 ng or 0.05 ng TeNT) into both tibialis anterior muscles. The maximum running velocity and accumulative running time of the groups were recorded during the following weeks. Three days after TeNT injections, the mice exhibited an increase in muscle tone of the injected tibialis anterior muscles but no generalized symptoms. However, we found that normal running in the complex wheel set-up was disturbed such that the maximum running velocity and running time of the mice decreased with the size of the dose. This effect peaked on the fifth and sixth nights after injection and returned to baseline level again within the next two weeks. With this novel in vivo automated paradigm we can accurately and objectively quantify the duration and degree of TeNT-induced focal increase in muscle tone.

Automatisierte motorische Rehabilitation

Automatisierte motorische Rehabilitation meint den Einsatz intelligenter Maschinen in der Rehabilitation der oberen und unteren Extremitat nach ZNS-Lasionen. Dieser neue Ansatz geht u.a. davon aus, dass n n neine positive Korrelation zwischen der Intensitat der Therapie und dem motorischen Outcome vorliegt (Kwakkel et al. 1999), n n nsich aufgabenspezifische repetitive Ansatze wie Laufbandtherapie (Hesse et al. 1994) als uberlegen erwiesen, n n njedoch der damit verbundene hohe Personalaufwand den wissenschaftlich begrundeten Wunsch nach moglichst viel Therapie im Klinikalltag begrenzt.