Error-enhanced augmented proprioceptive feedback in stroke rehabilitation training:a pilot study

Augmented feedback plays an essential role in stroke rehabilitation therapy. When a force is applied to the arm, an augmented sensory (proprioceptive) cue is provided. The question was to find out if stroke patients can learn reach-and retrieval movements with error-enhanced augmented sensory feedback. The movements were performed over a predefined path, and when deviating of the path a force is provided, as colliding to a wall of a tunnel. Two chronic stroke survivors (FM of 53 and 49) performed reach and retrieval movements in a virtual tunnel. When two consecutive series of 15 repetitions of the same movements were performed, there was a consistent decrease of collisions to the wall in the second series of movements. This indicates that these patients were able to learn the predefined trajectory by means of augmented proprioceptive feedback. Despite the small number of patients tested, this finding is promising for the usage of error-enhanced augmented proprioceptive feedback in rehabilitation therapy

Circle drawing as evaluative movement task in stroke rehabilitation: an explorative study

<p>Abstract</p> <p>Background</p> <p>The majority of stroke survivors have to cope with deficits in arm function, which is often measured with subjective clinical scales. The objective of this study is to examine whether circle drawing metrics are suitable objective outcome measures for measuring upper extremity function of stroke survivors.</p> <p>Methods</p> <p>Stroke survivors (n = 16) and healthy subjects (n = 20) drew circles, as big and as round as possible, above a table top. Joint angles and positions were measured. Circle area and roundness were calculated, and synergistic movement patterns were identified based on simultaneous changes of the elevation angle and elbow angle.</p> <p>Results</p> <p>Stroke survivors had statistically significant lower values for circle area, roundness and joint excursions, compared to healthy subjects. Stroke survivors moved significantly more within synergistic movement patterns, compared to healthy subjects. Strong correlations between the proximal upper extremity part of the Fugl-Meyer scale and circle area, roundness, joint excursions and the use of synergistic movement patterns were found.</p> <p>Conclusions</p> <p>The present study showed statistically significant differences in circle area, roundness and the use of synergistic movement patterns between healthy subjects and stroke survivors. These circle metrics are strongly correlated to stroke severity, as indicated by the proximal upper extremity part of the FM score.</p> <p>In clinical practice, circle area and roundness can give useful objective information regarding arm function of stroke survivors. In a research setting, outcome measures addressing the occurrence of synergistic movement patterns can help to increase understanding of mechanisms involved in restoration of post stroke upper extremity function.</p

Nature, timing, frequency and type of augmented feedback; does it influence motor relearning of the hemiparetic arm after stroke? A systematic review.

Purpose: To investigate the effect of different aspects and types of augmented feedback on motor functions and motor activities of the hemiparetic arm after stroke. - \ud Method: Systematic search of the scientific literature was performed in the Pubmed and Cochrane database from 1975 to March 2009. The augmented feedback used in the intervention was classified with respect to aspects (nature, timing and frequency) and types (auditory, sensory and visual). - \ud Results: The systematic literature search resulted in 299 citations. On the basis of inclusion and exclusion criteria, 23 full-text articles were included for analysis. There are some trends in favour of providing augmented knowledge of performance feedback, augmented auditory and combined sensory and visual feedback. No consistent effects on motor relearning were observed for summary or faded, terminal or concurrent, solely visual or solely sensory augmented feedback. - \ud Conclusions: On the basis of this study, it was not possible to determine which combinations of aspects and types of augmented feedback are most essential for a beneficial effect on motor activities and motor functions of the hemiparetic arm after stroke. This was due to the combination of multiple aspects and types of augmented feedback in the included studies. This systematic review indicates that augmented feedback in general has an added value for stroke rehabilitation

Body segments decoupling in sitting: Control of body posture from automatic chair adjustments

Background: Individuals who cannot functionally reposition themselves adopt a passive body posture and suffer from physical discomfort in long-term sitting. To regulate body load and to prevent sitting related mobility problems, proper posture control is important. The inability to reposition underlines the importance for seating interventions that control body posture from automatic chair adjustments. We developed an adjustable simulator chair that allows the alignment of the trunk, pelvis and thighs to be controlled independently. This study describes the system for decoupled body segments adjustment and develops a predictive model that computes angular chair configuration for desired body postures. - Methods: Eighteen healthy male subjects participated in this study. The experiment involved a protocol of five trials, each investigating the effect of individual chair segment angle adjustment on body segments rotation. Quasi-static chair adjustments were performed, in which angular chair configuration and body segments orientation were measured using an infrared motion capturing system and an inertia sensor attached on the pelvis. - Results: Linear best-fit equations together with the coefficients of determination were computed. Significant relations have been found between angular chair configuration and body segments orientation leading to an algorithm that predicts chair configuration for desired body posture. - Conclusions: The predictive algorithm seems applicable to compute angular chair configuration for desired body posture when the initial body–chair configuration is known. For clinical application, future experiments must be performed on impaired individuals to validate the algorithm in terms of accuracy

Influence of gravity compensation training on synergistic movement patterns of the upper extremity after stroke, a pilot study

Abstract Background The majority of stroke patients have to cope with impaired arm function. Gravity compensation of the arm instantaneously affects abnormal synergistic movement patterns. The goal of the present study is to examine whether gravity compensated training improves unsupported arm function. Methods Seven chronic stroke patients received 18 half-hour sessions of gravity compensated reach training, in a period of six weeks. During training a motivating computer game was played. Before and after training arm function was assessed with the Fugl-Meyer assessment and a standardized, unsupported circle drawing task. Synergistic movement patterns were identified based on concurrent changes in shoulder elevation and elbow flexion/extension angles. Results Median increase of Fugl-Meyer scores was 3 points after training. The training led to significantly increased work area of the hemiparetic arm, as indicated by the normalized circle area. Roundness of the drawn circles and the occurrence of synergistic movement patterns remained similar after the training. Conclusions A decreased strength of involuntary coupling might contribute to the increased arm function after training. More research is needed to study working mechanisms involved in post stroke rehabilitation training. The used training setup is simple and affordable and is therefore suitable to use in clinical settings.</p