Using the Flexor Reflex in a Chronic Stroke Patient for Gait Improvement: A Case Report

The flexor reflex or withdrawal reflex can be elicited by electrical stimulation of the sole of the foot, which serves as a reflex to protect the stimulated limb against tissue damage and consists of flexion movements in the hip, knee, and ankle joint. Triggering this reflex might improve walking abilities in hemiparetic patients. We report the first case of a chronic stroke patient with the most severe impairment of walking. She was examined with and without flexor reflex activation by the Incedo® system. Tests included a 10-m walk and a 2-min walk at baseline, after 3 weeks of training with the Incedo® system and after a follow-up 3 weeks later. Moreover, a kinematic gait analysis was done before and after the training period. At baseline, activation of the flexor reflex induced an improved gait velocity. After the training period, the patient walked twice as fast compared with baseline. Her gait velocity without Incedo® was faster than the gait velocity with Incedo® at baseline. Examination at follow-up indicated that the improvements remained almost unchanged. The kinematic analysis showed an improved stride length and gait velocity during flexor reflex activation. Initially, the foot was elevated higher above the ground during flexor reflex activation. In conclusion, this first case report of a chronic stroke patient demonstrates that flexor reflex activation is feasible and improves gait parameters despite severe impairment of walking abilities

Objective assessment of motor fatigue in multiple sclerosis using kinematic gait analysis: a pilot study

<p>Abstract</p> <p>Background</p> <p>Fatigue is a frequent and serious symptom in patients with Multiple Sclerosis (MS). However, to date there are only few methods for the objective assessment of fatigue. The aim of this study was to develop a method for the objective assessment of motor fatigue using kinematic gait analysis based on treadmill walking and an infrared-guided system.</p> <p>Patients and methods</p> <p>Fourteen patients with clinically definite MS participated in this study. Fatigue was defined according to the Fatigue Scale for Motor and Cognition (FSMC). Patients underwent a physical exertion test involving walking at their pre-determined patient-specific preferred walking speed until they reached complete exhaustion. Gait was recorded using a video camera, a three line-scanning camera system with 11 infrared sensors. Step length, width and height, maximum circumduction with the right and left leg, maximum knee flexion angle of the right and left leg, and trunk sway were measured and compared using paired t-tests (α = 0.005). In addition, variability in these parameters during one-minute intervals was examined. The fatigue index was defined as the number of significant mean and SD changes from the beginning to the end of the exertion test relative to the total number of gait kinematic parameters.</p> <p>Results</p> <p>Clearly, for some patients the mean gait parameters were more affected than the variability of their movements while other patients had smaller differences in mean gait parameters with greater increases in variability. Finally, for other patients gait changes with physical exertion manifested both in changes in mean gait parameters and in altered variability. The variability and fatigue indices correlated significantly with the motoric but not with the cognitive dimension of the FSMC score (R = -0.602 and R = -0.592, respectively; P < 0.026).</p> <p>Conclusions</p> <p>Changes in gait patterns following a physical exertion test in patients with MS suffering from motor fatigue can be measured objectively. These changes in gait patterns can be described using the motor fatigue index and represent an objective measure to assess motor fatigue in MS patients. The results of this study have important implications for the assessments and treatment evaluations of fatigue in MS.</p

Quantifizierung motorischer Fatigue durch Bewegungsanalyse : Entwicklung und Evaluation eines neuen Diagnostikverfahrens bei Patienten mit Multipler Sklerose

Motorische Fatigue ist eines der häufigsten und belastendsten Symptome bei Patienten mit Multipler Sklerose. Trotz des häufigen Auftretens dieses Symp-toms und seiner teilweise schwerwiegenden Folgen für die Betroffenen existierten bisher keine Messinstrumente und -verfahren, welche motorische Fatigue objektiv erfassen können. Die vorliegende Arbeit beschäftigt sich mit der Entwicklung und Testung eines Verfahrens zur objektiven Messung von motorischer Fatigue bei Patienten mit Multipler Sklerose und nach einem Schlaganfall. Das vorliegende Dissertationsvorhaben ist eine kumulative Arbeit aus drei empirischen Untersuchungen.In der ersten Studie wurde das neue Verfahren zur Quantifizierung von Verän-derungen im Gangmuster entwickelt und erfolgreich an gesunden Probanden getestet. Hierbei wurden die Eigenschaften des Grenzzyklus-Attraktors heran-gezogen. Diese Methode ermöglicht die Identifizierung von Veränderungen im Bewegungsmuster bei Personen sowohl auf der Gruppen- als auch auf der In-dividualebene, indem die Veränderungen in der Gangcharakteristik und in der Gangvariabilität erfasst werden.In der zweiten Studie wurde das neu entwickelte Verfahren zur Quantifizierung von motorischer Fatigue bei Patienten mit Multipler Sklerose herangezogen. In diesem Zusammenhang wurde auch der Fatigue Index Kliniken Schmieder zur objektiven Erfassung von motorischer Fatigue entwickelt. Mit Hilfe des Fatigue Index Kliniken Schmieder konnten zum ersten Mal Veränderungen im Gangmuster auf Grund von akut auftretender motorischer Fatigue bei Patienten mit Multipler Sklerose erfasst werden. Zudem konnten verlässliche Grenzwerte, die eine klare Diagnose von motorischer Fatigue ermöglichten, bestimmt werden. Weiterhin konnte demonstriert werden, dass motorische Fatigue keinen Zusammenhang mit der muskulären Fatigue aufweist.In der dritten Studie wurde der Fatigue Index Kliniken Schmieder zur Messung von motorischer Fatigue bei Patienten nach einem Schlaganfall erfolgreich eingesetzt. Dies ermöglichte erstmalig einen Vergleich der motorischen Fatigue anhand der empirischen Daten zwischen den Schlaganfall-Patienten und Patienten mit Multipler Sklerose. Die Schlaganfall-Patienten zeigten ein ähnliches Ausmaß an motorischer Fatigue wie die Patienten mit Multipler Sklerose. Der Fatigue Index Kliniken Schmieder erwies sich als robust gegenüber bereits bestehenden chronischen Gangbeeinträchtigungen.publishe

A novel approach to quantify time series differences of gait data using attractor attributes

In this paper we introduce a new method to expressly use live/corporeal data in quantifying differences of time series data with an underlying limit cycle attractor; and apply it using an example of gait data. Our intention is to identify gait pattern differences between diverse situations and classify them on group and individual subject levels. First we approximated the limit cycle attractors, from which three measures were calculated: δM amounts to the difference between two attractors (a measure for the differences of two movements), δD computes the difference between the two associated deviations of the state vector away from the attractor (a measure for the change in movement variation), and δF, a combination of the previous two, is an index of the change. As an application we quantified these measures for walking on a treadmill under three different conditions: normal walking, dual task walking, and walking with additional weights at the ankle. The new method was able to successfully differentiate between the three walking conditions. Day to day repeatability, studied with repeated trials approximately one week apart, indicated excellent reliability for δM (ICCave > 0.73 with no differences across days; p > 0.05) and good reliability for δD (ICCave = 0.414 to 0.610 with no differences across days; p > 0.05). Based on the ability to detect differences in varying gait conditions and the good repeatability of the measures across days, the new method is recommended as an alternative to expensive and time consuming techniques of gait classification assessment. In particular, the new method is an easy to use diagnostic tool to quantify clinical changes in neurological patients

Using an upper extremity exoskeleton for semi-autonomous exercise during inpatient neurological rehabilitation- a pilot study

Abstract Background Motor deficits are the most common symptoms after stroke. There is some evidence that intensity and amount of exercises influence the degree of improvement of functions within the first 6 months after the injury. The purpose of this pilot study was to evaluate the feasibility and acceptance of semi-autonomous exercises with an upper extremity exoskeleton in addition to an inpatient rehabilitation program. In addition, changes of motor functions were examined. Methods Ten stroke patients with a severe upper extremity paresis were included. They were offered to perform a semi-autonomous training with a gravity-supported, computer-enhanced device (Armeo®Spring, Hocoma AG) six times per week for 4 weeks. Feasibility was evaluated by weekly structured interviews with patients and supervisors. Motor functions were assessed before and after the training period using the Wolf Motor Function Test (WMFT). The Wilcoxon Signed Rank Test was used for assessing pre-post differences. The Pearson correlation co-efficient was used for correlating the number of completed sessions with the change in motor function. Acceptance of the device and the level of satisfaction with the training were determined by a questionnaire based on visual analogue scales. Results Neither patients nor supervisors reported side effects. However, one patient had to be excluded from analysis because of transportation difficulties from the ward to the treatment facility. Therefore, analysis was based on nine patients. On average, 13.2 (55%) sessions were realized. WMFT results showed significant improvements of proximal arm functions. The number of sessions correlated with the degree of shoulder force improvement. Patients rated the exercises to be motivating, and enjoyable and would continue using the Armeo®Spring at home if they had the opportunity. Conclusion Using an upper extremity exoskeleton for semi-autonomous training in an inpatient setting is feasible without side effects and is positively rated by the patients. It might further support the recovery of upper extremity function. Trial registration The trial was retrospectively registered. Registration number ISRCTN42633681

Difference in motor fatigue between patients with stroke and patients with multiple sclerosis: a pilot study

Fatigue is often reported in stroke patients. However, it is still unclear if fatigue in stroke patients is more prominent, more frequent or more "typical" than in patients with multiple sclerosis (MS) and if the pathophysiology differs between these two populations. The purpose of this study was to compare motor fatigue and fatigue-induced changes in kinematic gait parameters between stroke patients, MS patients, and healthy persons. Gait parameters at the beginning and end of a treadmill walking test were assessed in 10 stroke patients, 40 MS patients, and 20 healthy subjects. The recently developed Fatigue index Kliniken Schmieder (FKS) based on change of the movement's attractor and its variability was used to measure motor fatigue. Six stroke patients had a pathological FKS. The FKS (indicating the level of motor fatigue) in stroke patients was similar compared to MS patients. Stroke patients had smaller step length, step height and greater step width, circumduction with the right and left leg, and greater sway compared to the other groups at the beginning and at the end of test. A severe walking impairment in stroke patients does not necessarily cause a pathological FKS indicating motor fatigue. Moreover, the FKS can be used as a measure of motor fatigue in stroke and MS and may also be applicable to other diseases

Objective assessment of motor fatigue in multiple sclerosis : the Fatigue index Kliniken Schmieder (FKS)

Fatigue is a common and frequently disabling symptom of multiple sclerosis (MS). The aim of this study was to develop the Fatigue index Kliniken Schmieder (FKS) for detecting motor fatigue in patients with MS using kinematic gait analysis. The FKS relies on the chaos theoretical term "attractor", which, if unchanged, is a necessary and sufficient indicator of a stable dynamical system. We measured the acceleration of the feet at the beginning of and shortly before stopping a treadmill walking task in 20 healthy subjects and 40 patients with multiple sclerosis. The attractor and movement variability were calculated. In the absence of muscular exhaustion a significant difference in the attractor and movement variability between the two time points demonstrates altered motor control indicating fatigue. Subjects were classified using the FKS. All healthy subjects had normal FKS and thus no fatigue. 29 patients with MS were classified into a fatigue group and 11 patients into a non-fatigue group. This classification agreed with the physician’s observation and video analyses in up to 97 % of cases. The FKS did not correlate significantly with the overall and motor dimensions of the fatigue questionnaire scores in patients with MS and motor fatigue. The common concept of fatigue as overall subjective sensation of exhaustion can be affected by conditions including depression, sleep disorder and others. FKS constitutes a robust and objective measure of changes in motor performance. Therefore, the FKS allows correct identification of motor fatigue even in cases where common comorbidities mask motor fatigue

Intraclass Correlation Coefficient (ICC) and the probability of a difference across days for <i>δM</i> and <i>δD</i> of normal walking without any load (N), walking with an additional mental task (M), and walking with two kilogram weights on each foot (W).

<p>Intraclass Correlation Coefficient (ICC) and the probability of a difference across days for <i>δM</i> and <i>δD</i> of normal walking without any load (N), walking with an additional mental task (M), and walking with two kilogram weights on each foot (W).</p