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| Author | Merdler, T.; Liebermann, D.G.; Levin, M.F.; Berman, S. | ||||
| Title | Arm-plane representation of shoulder compensation during pointing movements in patients with stroke | Type | Journal Article | ||
| Year | 2013 | Publication | Journal of Electromyography and Kinesiology : Official Journal of the International Society of Electrophysiological Kinesiology | Abbreviated Journal | J Electromyogr Kinesiol |
Volume  |
23 | Issue | 4 | Pages | 938–947 |
| Keywords | Kinematics; Arm movement; Rehabilitation | ||||
| Abstract | Improvements in functional motor activities are often accompanied by motor compensations to overcome persistent motor impairment in the upper limb. Kinematic analysis is used to objectively quantify movement patterns including common motor compensations such as excessive trunk displacement during reaching. However, a common motor compensation to assist reaching, shoulder abduction, is not adequately characterized by current motion analysis approaches. We apply the arm-plane representation that accounts for the co-variation between movements of the whole arm, and investigate its ability to identify and quantify compensatory arm movements in stroke subjects when making forward arm reaches. This method has not been previously applied to the analysis of motion deficits. Sixteen adults with right post-stroke hemiparesis and eight healthy age-matched controls reached in three target directions (14 trials/target; sampling rate: 100Hz). Arm-plane movement was validated against endpoint, joint, and trunk kinematics and compared between groups. In stroke subjects, arm-plane measures were correlated with arm impairment (Fugl-Meyer Assessment) and ability (Box and Blocks) scores and were more sensitive than clinical measures to detect mild motor impairment. Arm-plane motion analysis provides new information about motor compensations involving the co-variation of shoulder and elbow movements that may help to understand the underlying motor deficits in patients with stroke. | ||||
| Address | Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer-Sheva, Israel | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1050-6411 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:23566477 | Approved | no | ||
| Call Number | Serial | 69 | |||
| Permanent link to this record | |||||
| Author | Harel Arzi; Tal Krasovsky; Moshe Pritsch; Dario G. Liebermann | ||||
| Title | Movement control in patients with shoulder instability: a comparison between patients after open surgery and nonoperated patients | Type | Journal Article | ||
| Year | 2014 | Publication | Journal of Shoulder and Elbow Surgery | Abbreviated Journal | |
| Volume |
23 | Issue | 7 | Pages | 982–992 |
| Keywords | Smoothness; kinesthesis; arm kinematics; shoulder instability; open surgery | ||||
| Abstract | Background Open surgery to correct shoulder instability is deemed to facilitate recovery of static and dynamic motor functions. Postoperative assessments focus primarily on static outcomes (e.g., repositioning accuracy). We introduce kinematic measures of arm smoothness to assess shoulder patients after open surgery and compare them with nonoperated patients. Performance among both groups of patients was hypothesized to differ. Postsurgery patients were expected to match healthy controls. Methods All participants performed pointing movements with the affected/dominant arm fully extended at fast, preferred, and slow speeds (36 trials per subject). Kinematic data were collected (100 Hz, 3 seconds), and mixed-design analyses of variance (group, speed) were performed with movement time, movement amplitude, acceleration time, and model-observed similarities as dependent variables. Nonparametric tests were performed for number of velocity peaks. Results Nonoperated and postsurgery patients showed similarities at preferred and faster movement speeds but not at slower speed. Postsurgery patients were closer to maximally smoothed motion and differed from healthy controls mainly during slow arm movements (closer to maximal smoothness, larger movement amplitude, shorter movement time, and lower number of peaks; i.e., less movement fragmentation). Conclusions Arm kinematic analyses suggest that open surgery stabilizes the shoulder but does not necessarily restore normal movement quality. Patients with recurrent anterior shoulder instability (RASI) seem to implement a “safe” but nonadaptive mode of action whereby preplanned stereotypical movements may be executed without depending on feedback. Rehabilitation of RASI patients should focus on restoring feedback-based movement control. Clinical assessment of RASI patients should include higher order kinematic descriptors. |
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| Notes | Approved | no | |||
| Call Number | Serial | 74 | |||
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| Author | Davidowitz, I.; Parmet, Y.; Frenkel-Toledo, S.; Banina, M.C.; Soroker, N.; Solomon, J.M.; Liebermann, D.G.; Levin, M.F.; Berman, S. | ||||
| Title | Relationship Between Spasticity and Upper-Limb Movement Disorders in Individuals With Subacute Stroke Using Stochastic Spatiotemporal Modeling | Type | Journal Article | ||
| Year | 2019 | Publication | Neurorehabilitation and Neural Repair | Abbreviated Journal | Neurorehabil Neural Repair |
| Volume |
33 | Issue | 2 | Pages | 141-152 |
| Keywords | Gaussian mixture model; Kullback-Liebler divergence; spasticity; stroke; upper-limb kinematics | ||||
| Abstract | BACKGROUND: Spasticity is common in patients with stroke, yet current quantification methods are insufficient for determining the relationship between spasticity and voluntary movement deficits. This is partly a result of the effects of spasticity on spatiotemporal characteristics of movement and the variability of voluntary movement. These can be captured by Gaussian mixture models (GMMs). OBJECTIVES: To determine the influence of spasticity on upper-limb voluntary motion, as assessed by the bidirectional Kullback-Liebler divergence (BKLD) between motion GMMs. METHODS: A total of 16 individuals with subacute stroke and 13 healthy aged-equivalent controls reached to grasp 4 targets (near-center, contralateral, far-center, and ipsilateral). Two-dimensional GMMs (angle and time) were estimated for elbow extension motion. BKLD was computed for each individual and target, within the control group and between the control and stroke groups. Movement time, final elbow angle, average elbow velocity, and velocity smoothness were computed. RESULTS: Between-group BKLDs were much larger than within control-group BKLDs. Between-group BKLDs for the near-center target were lower than those for the far-center and contralateral targets, but similar to that for the ipsilateral target. For those with stroke, the final angle was lower for the near-center target, and the average velocity was higher. Velocity smoothness was lower for the near-center than for the ipsilateral target. Elbow flexor and extensor passive muscle resistance (Modified Ashworth Scale) strongly explained BKLD values. CONCLUSIONS: Results support the view that individuals with poststroke spasticity have a velocity-dependent reduction in active elbow joint range and that BKLD can be used as an objective measure of the effects of spasticity on reaching kinematics. | ||||
| Address | 1 Ben-Gurion University of the Negev, Beer-Sheva, Israel | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1545-9683 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:30744528 | Approved | no | ||
| Call Number | Serial | 93 | |||
| Permanent link to this record | |||||
| Author | Wilf, M.; Korakin, A.; Bahat, Y.; Koren, O.; Galor, N.; Dagan, O.; Wright, W.G.; Friedman, J.; Plotnik, M. | ||||
| Title | Using virtual reality-based neurocognitive testing and eye tracking to study naturalistic cognitive-motor performance | Type | Journal Article | ||
| Year | 2024 | Publication | Neuropsychologia | Abbreviated Journal | Neuropsychologia |
| Volume |
194 | Issue | Pages | 108744 | |
| Keywords | Humans; Aged; *Eye-Tracking Technology; Cognition; Executive Function; *Virtual Reality; Aging; Color trails test; Fall risk; Hand kinematics; Pupil; Virtual reality | ||||
| Abstract | Natural human behavior arises from continuous interactions between the cognitive and motor domains. However, assessments of cognitive abilities are typically conducted using pen and paper tests, i.e., in isolation from “real life” cognitive-motor behavior and in artificial contexts. In the current study, we aimed to assess cognitive-motor task performance in a more naturalistic setting while recording multiple motor and eye tracking signals. Specifically, we aimed to (i) delineate the contribution of cognitive and motor components to overall task performance and (ii) probe for a link between cognitive-motor performance and pupil size. To that end, we used a virtual reality (VR) adaptation of a well-established neurocognitive test for executive functions, the 'Color Trails Test' (CTT). The VR-CTT involves performing 3D reaching movements to follow a trail of numbered targets. To tease apart the cognitive and motor components of task performance, we included two additional conditions: a condition where participants only used their eyes to perform the CTT task (using an eye tracking device), incurring reduced motor demands, and a condition where participants manually tracked visually-cued targets without numbers on them, incurring reduced cognitive demands. Our results from a group of 30 older adults (>65) showed that reducing cognitive demands shortened completion times more extensively than reducing motor demands. Conditions with higher cognitive demands had longer target search time, as well as decreased movement execution velocity and head-hand coordination. We found larger pupil sizes in the more cognitively demanding conditions, and an inverse correlation between pupil size and completion times across individuals in all task conditions. Lastly, we found a possible link between VR-CTT performance measures and clinical signatures of participants (fallers versus non-fallers). In summary, performance and pupil parameters were mainly dependent on task cognitive load, while maintaining systematic interindividual differences. We suggest that this paradigm opens the possibility for more detailed profiling of individual cognitive-motor performance capabilities in older adults and other at-risk populations. | ||||
| Address | Center of Advanced Technologies in Rehabilitation, Sheba Medical Center, Israel; Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel. Electronic address: Meir.Plotnik@sheba.health.gov.il | ||||
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| Language | English | Summary Language | Original Title | ||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0028-3932 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:38072162 | Approved | no | ||
| Call Number | Serial | 123 | |||
| Permanent link to this record | |||||