Characterizing coordination of grasp and twist in hand function of healthy and post-stroke subjects (original) (raw)
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Hand Grip and Load Force Coordination of the Ipsilesional Hand of Chronic Stroke Individuals
Journal of Motor Behavior, 2019
Object manipulation depends on a refined control of grip force (GF) and load force (LF). After a brain injury, the GF control is altered in the paretic hand but what happens with the non-paretic hand is still unclear. In this study, we compared the GF control and GF-LF coordination of the non-paretic hand of 10 stroke individuals who suffered right brain damage (RBD) and 10 who suffered left brain damage (LBD), with 20 healthy individuals during lifting and oscillation task, using an instrumented object. GF was recorded with a force transducer, and LF was estimated from the object weight and acceleration. Overall, the ipsilesional hand of stroke individuals, independent of the lesion side, presented similar GF control and GF-LF coordination. However, LBD individuals took longer to start lifting the object, which may be due to the need of more time to obtain somatosensory information from the contact with the object. The findings indicate that stroke individuals preserve their ability to control and coordinate GF and LF when using their ipsilesional hand for object manipulation and the left hemisphere may play an essential role in the processing of somatosensory information needed for the GF control.
Multi-finger coordination in healthy subjects and stroke patients: a mathematical modelling approach
Journal of NeuroEngineering and Rehabilitation, 2011
Background: Approximately 60% of stroke survivors experience hand dysfunction limiting execution of daily activities. Several methods have been proposed to objectively quantify fingers' joints range of motion (ROM), while few studies exist about multi-finger coordination during hand movements. The present work analysed this aspect, by providing a complete characterization of spatial and temporal aspects of hand movement, through the mathematical modelling of multi-joint finger motion in healthy subjects and stroke patients. Methods: Hand opening and closing movements were examined in 12 healthy volunteers and 14 hemiplegic stroke survivors by means of optoelectronic kinematic analysis. The flexion/extension angles of metacarpophalangeal (MCPJ) and proximal interphalangeal joints (IPJ) of all fingers were computed and mathematically characterized by a four-parameter hyperbolic tangent function. Accuracy of the selected model was analysed by means of coefficient of determination (R 2 ) and root mean square error (RMSE). Test-retest reliability was quantified by intraclass correlation coefficient (ICC) and test-retest errors. Comparison between performances of healthy controls and stroke subjects were performed by analysing possible differences in parameters describing angular and temporal aspects of hand kinematics and inter-joint, inter-digit coordination. Results: The angular profiles of hand opening and closing were accurately characterized by the selected model, both in healthy controls and in stroke subjects (R 2 > 0.973, RMSE < 2.0°). Test-retest reliability was found to be excellent, with ICC > 0.75 and remarking errors comparable to those obtained with other methods. Comparison with healthy controls revealed that hemiparetic hand movement was impaired not only in joints ROM but also in the temporal aspects of motion: peak velocities were significantly decreased, inter-digit coordination was reduced of more than 50% and inter-joint coordination patterns were highly disrupted. In particular, the stereotypical proximal-to-distal opening sequence (reversed during hand closing) found in healthy subjects, was altered in stroke subjects who showed abnormally high delay between IPJ and MCPJ movement or reversed moving sequences.
Modification of Hand Muscular Synergies in Stroke Patients after Robot-Aided Rehabilitation
Applied Sciences, 2022
The central nervous system (CNS) is able to control a very high number of degrees of freedom to perform complex movements of both upper and lower limbs. However, what strategies the CNS adopts to perform complex tasks are not completely clear and are still being studied. Recent studies confirm that stroke subjects with mild and moderate impairment show altered upper limb muscle patterns, but the muscular patterns of the hand have not completely investigated, although the hand represents a paramount tool for performing activities of daily living (ADLs) and stroke can significantly alter the mobilization of this part of the body. In this context, this study aims at investigating hand muscular synergies in chronic stroke patients and evaluating some possible benefits in the robot-aided rehabilitation treatment of the hand in these subjects. Seven chronic stroke patients with mild-to-moderate impairment (FM>30) were involved in this study. They received a 5-week robot-aided rehabilit...
Brain Sciences
Stroke is one of the leading causes of human disability globally. Motor function deficits resulting from a stroke affect the entire body, but relatively often it is the upper limbs that remain ineffective, which is very limiting in everyday life activities. The finding in neurorehabilitation that trunk control contributes to upper limb function is relatively common but has not been confirmed in clinical trials. This observational prospective study aims to analyze the effect of the position of the trunk and the affected upper limb on the coordination and grip strength of the affected dominant and non-dominant hand and wrist in people after ischemic stroke. The research was carried out at the Department of Neurological Rehabilitation, on a group of 60 patients with acute ischemic stroke. A Hand Tutor device and a hand dynamometer were used for the main measurements of the motor coordination parameters (maximum range of motion, frequency of movement) and the grip strength of the domina...
Hand function and type of grasp used by chronic stroke individuals in actual environment
Topics in Stroke Rehabilitation, 2019
Background: Knowledge of paretic upper limb (UL) use in the actual environment is crucial for defining treatment strategies that are likely to enhance performance. Objective: To quantify the hand function and type of grasp performed in the actual environment following stroke and determine if any differences in hand use are dependent on the degree of motor impairment. Method: This cross-sectional study enrolled 41 participants with chronic hemiparesis classified as having either mild (11), moderate (20), or severe (10) UL impairment. A behavioral map was used while observing hand use over the 4-h experimental period, during which we checked: activityunimanual, bimanual or non-task-related; hand functionstabilization, manipulation, reach-to-grasp, gesture, support or push; and type of graspdigital or whole-hand. Results: Participants with severe impairment did not use the paretic UL spontaneously; analyzing the moderate and mild subgroup together, the predominant UL hand functions were stabilization and manipulation, the paretic UL performs the stabilization function using the whole-hand more frequently (71.2%) than digital (28.8%) grasp. In the subgroup analysis, the paretic and non-paretic UL in the moderate and the paretic UL in the mild subgroup perform the whole-hand stabilization more frequently than digital. Digital grasp is more accomplished by the non-paretic UL in reach-to-grasp hand function, particularly in the mild subgroup. Conclusion: The paretic UL is predominantly employed for stabilization function using a wholehand grasp. The type of grasp in the actual environment is affected by motor impairment, and greater motor impairment leads to the performance of less complex tasks.
Background: Rehabilitation of hand function is challenging, and only few studies have investigated robot-assisted rehabilitation focusing on distal joints of the upper limb. This paper investigates the feasibility of using the HapticKnob, a table-top end-effector device, for robot-assisted rehabilitation of grasping and forearm pronation/ supination, two important functions for activities of daily living involving the hand, and which are often impaired in chronic stroke patients. It evaluates the effectiveness of this device for improving hand function and the transfer of improvement to arm function. Methods: A single group of fifteen chronic stroke patients with impaired arm and hand functions (Fugl-Meyer motor assessment scale (FM) 10-45/66) participated in a 6-week 3-hours/week rehabilitation program with the HapticKnob. Outcome measures consisted primarily of the FM and Motricity Index (MI) and their respective subsections related to distal and proximal arm function, and were assessed at the beginning, end of treatment and in a 6-weeks follow-up. Results: Thirteen subjects successfully completed robot-assisted therapy, with significantly improved hand and arm motor functions, demonstrated by an average 3.00 points increase on the FM and 4.55 on the MI at the completion of the therapy (4.85 FM and 6.84 MI six weeks post-therapy). Improvements were observed both in distal and proximal components of the clinical scales at the completion of the study (2.00 FM wrist/hand, 2.55 FM shoulder/elbow, 2.23 MI hand and 4.23 MI shoulder/elbow). In addition, improvements in hand function were observed, as measured by the Motor Assessment Scale, grip force, and a decrease in arm muscle spasticity. These results were confirmed by motion data collected by the robot. Conclusions: The results of this study show the feasibility of this robot-assisted therapy with patients presenting a large range of impairment levels. A significant homogeneous improvement in both hand and arm function was observed, which was maintained 6 weeks after end of the therapy.
Sensors
The Action Research Arm Test (ARAT) can provide subjective results due to the difficulty assessing abnormal patterns in stroke patients. The aim of this study was to identify joint impairments and compensatory grasping strategies in stroke patients with left (LH) and right (RH) hemiparesis. An experimental study was carried out with 12 patients six months after a stroke (three women and nine men, mean age: 65.2 ± 9.3 years), and 25 healthy subjects (14 women and 11 men, mean age: 40.2 ± 18.1 years. The subjects were evaluated during the performance of the ARAT using a data glove. Stroke patients with LH and RH showed significantly lower flexion angles in the MCP joints of the Index and Middle fingers than the Control group. However, RH patients showed larger flexion angles in the proximal interphalangeal (PIP) joints of the Index, Middle, Ring, and Little fingers. In contrast, LH patients showed larger flexion angles in the PIP joints of the Middle and Little fingers. Therefore, the...
PLOS ONE, 2013
Significant functional impairment of the hand is commonly observed in stroke survivors. Our previous studies suggested that the inability to modulate muscle coordination patterns according to task requirements may be substantial after stroke, but these limitations have not been examined directly. In this study, we aimed to characterize post-stroke impairment in the ability to modulate muscle coordination patterns across tasks and its correlation with hand impairment. Fourteen stroke survivors, divided into a group with severe hand impairment (8 subjects) and a group with moderate hand impairment (6 subjects) according to their clinical functionality score, participated in the experiment. Another four neurologically intact subjects participated in the experiment to serve as a point of comparison. Activation patterns of nine hand and wrist muscles were recorded using surface electromyography while the subjects performed six isometric tasks. Patterns of covariation in muscle activations across tasks, i.e., muscle modules, were extracted from the muscle activation data. Our results showed that the degree of reduction in the inter-task separation of the multi-muscle activation patterns was indicative of the clinical functionality score of the subjects (mean value = 26.2 for severely impaired subjects, 38.1 for moderately impaired subjects). The values for moderately impaired subjects were much closer to those of the impaired subjects (mean value = 46.1). The number of muscle modules extracted from the muscle activation patterns of a subject across six tasks, which represents the degree of motor complexity, was found to be correlated with the clinical functionality score (R = 0.68). Greater impairment was also associated with a change in the muscle module patterns themselves, with greater muscle coactivation. A substantial reduction in the degrees-of-freedom of the multi-muscle coordination poststroke was apparent, and the extent of the reduction, assessed by the stated metrics, was strongly associated with the level of clinical impairment.
Bimanual force control strategies in chronic stroke: Finger extension versus power grip
Neuropsychologia, 2012
Stroke leads to motor asymmetries in the flexor and extensor muscles of the hand. Typically, the strength deficits in the extensors are greater than the flexors. The impact of differential motor abilities of these muscle groups on the execution of bimanual force control tasks in individuals with stroke is unknown. The primary purpose of this study was to determine the influence of task constraints on visually guided bimanual force control in chronic stroke. Stroke survivors and age-matched individuals performed bimanual isometric contractions for 20 s to match target submaximal force levels. Online visual feedback of the total force (sum of the forces produced by both hands) was provided. The task constraints were manipulated by (a) finger extension, and (b) finger flexion (power grip). Force asymmetry was indexed by the proportion of force contributed by the paretic hand to the total force. The stroke group demonstrated task-specific asymmetry in bimanual force control. Specifically, the paretic hand contributed less force than the non-paretic hand in finger extension whereas this relationship was reversed in power grip. Importantly, regardless of the nature of the task, reduction in motor impairments was associated with increased symmetry and coordination in bimanual tasks. Further, bimanual submaximal grip force control revealed asymmetry and coordination deficits that are not identified by investigating bimanual maximal force production alone. The motor control strategy adopted to optimize performance on bimanual tasks revealed the altered force production of the paretic hand due to the combined effect of extensor weakness and enhanced flexor bias following stroke. Bimanual asymmetries in stroke survivors highlight the need for identifying and treating the taskspecific impairments for maximizing motor recovery post stroke.
Effect of Weighted Hand Movements on Hand Function in Chronic Stroke Patients
International Journal of Physiotherapy and Research, 2017
Background: Hand dysfunction is a common problem of stroke patients and it is the main cause of impairment of the upper limb. Finding new method to improve hand performance will decrease the disability of chronic stroke patients. Aim of the study: to study the effect of bilateral hand training with weight on the non paretic hand on the hand performance and time of performance in chronic stroke patients. Materials and Methods: Thirty left chronic stroke patients participated in this study. The patients were assigned randomly into two equal groups. Group one (G1) received unilateral hand training and group two (G2) received bilateral hand training with weight on non affected hand. Both groups assessed two times before starting training program and after two months of training by Fugl meyer assessment scale, Wolf motor function test and hand dynamometer for the motor performance, time of performance and hand grip respectively. Results: the patients in G2 showed significant improvement in the hand performance (P<.0001) and significant decrease in the time of performance (P<.001) and also significant improvement of hand grip (P<.0001). Conclusion: Bilateral hand movement with weight on the non affected hand has a significant effect on improving hand performance and decreasing the time of performance and increasing hand grip than unilateral hand movement.