Forelimb Cortical Stroke Reduces Precision of Motor Control in Mice

Background and Objective. Rodent models of stroke impairment should capture translatable features of behavioral injury. This study characterized poststroke impairment of motor precision separately from strength in an automated behavioral assay. Methods. We measured skilled distal forelimb reach-and-grasp motions within a target force range requiring moderate-strength. We assessed whether deficits reflected an increase in errors on only one or both sides of the target force range after photothrombotic cortical stroke. Results. Pull accuracy was impaired for 6 weeks after stroke, with errors redistributing to both sides of the target range. No decrease in maximum force was measured. Conclusions. This automated reach task measures sustained loss of motor precision following cortical stroke in mice.

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The effects of anxiety and dual-task on upper limb motor control of chronic stroke survivors

Scientific Reports ◽

10.1038/s41598-020-71845-7 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Mahnaz Hejazi-Shirmard ◽

Laleh Lajevardi ◽

Mehdi Rassafiani ◽

Ghorban Taghizadeh

Keyword(s):

Motor Control ◽

Upper Limb ◽

Dual Task ◽

Chronic Stroke ◽

Stroke Survivors ◽

High Anxiety ◽

Reach And Grasp ◽

Stroke Group ◽

Task Conditions ◽

Hand Opening

Abstract This study was designed to investigate the effects of anxiety and dual-task on reach and grasp motor control in chronic stroke survivors compared with age- and sex-matched healthy subjects (HC). Reach and grasp kinematic data of 68 participants (high-anxiety stroke (HA-stroke), n = 17; low-anxiety stroke (LA-stroke), n = 17; low-anxiety HC, n = 17; and high-anxiety HC, n = 17) were recorded under single- and dual-task conditions. Inefficient reach and grasp of stroke participants, especially HA-stroke were found compared with the control groups under single- and dual-task conditions as evidenced by longer movement time (MT), lower and earlier peak velocity (PV) as well as delayed and smaller hand opening. The effects of dual-task on reach and grasp kinematic measures were similar between HCs and stroke participants (i.e., increased MT, decreased PV that occurred earlier, and delayed and decreased hand opening), with greater effect in stroke groups than HCs, and in HA-stroke group than LA-stroke group. The results indicate that performing a well-learned upper limb movement with concurrent cognitive task leads to decreased efficiency of motor control in chronic stroke survivors compared with HCs. HA-stroke participants were more adversely affected by challenging dual-task conditions, underlying importance of assessing anxiety and designing effective interventions for it in chronic stroke survivors.

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Fatigue-free operation of most body-powered prostheses not feasible for majority of users with trans-radial deficiency

Prosthetics and Orthotics International ◽

10.1177/0309364617708651 ◽

2017 ◽

Vol 42 (1) ◽

pp. 84-92 ◽

Cited By ~ 10

Author(s):

Mona Hichert ◽

Alistair N Vardy ◽

Dick Plettenburg

Keyword(s):

Daily Basis ◽

Maximum Force ◽

Force Transmission ◽

Anthropometric Measures ◽

Physical Strength ◽

Long Duration ◽

Arm Circumference ◽

Cable Force ◽

Cable Forces ◽

Force Range

Background: Body-powered prostheses require cable operation forces between 33 and 131 N. The accepted upper limit for fatigue-free long-duration operation is 20% of a users’ maximum cable operation force. However, no information is available on users’ maximum force. Objectives: To quantify users’ maximum cable operation force and to relate this to the fatigue-free force range for the use of body-powered prostheses. Study design: Experimental trial. Methods: In total, 23 subjects with trans-radial deficiencies used a bypass prosthesis to exert maximum cable force three times during 3 s and reported discomfort or pain on a body map. Additionally, subjects’ anthropometric measures were taken to relate to maximum force. Results: Subjects generated forces ranging from 87 to 538 N. Of the 23 subjects, 12 generated insufficient maximum cable force to operate 8 of the 10 body-powered prostheses fatigue free. Discomfort or pain did not correlate with the magnitude of maximum force achieved by the subjects. Nine subjects indicated discomfort or pain. No relationships between anthropometry and maximal forces were found except for maximum cable forces and the affected upper-arm circumference for females. Conclusion: For a majority of subjects, the maximal cable force was lower than acceptable for fatigue-free prosthesis use. Discomfort or pain occurred in ~40% of the subjects, suggesting a suboptimal force transmission mechanism. Clinical relevance The physical strength of users determines whether a body-powered prosthesis is suitable for comfortable, fatigue-free long-duration use on a daily basis. High cable operation forces can provoke discomfort and pain for some users, mainly in the armpit. Prediction of the users’ strength by anthropometric measures might assist the choice of a suitable prosthesis.

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Cervical Epidural Electrical Stimulation Restores Voluntary Arm Control In Paralyzed Monkeys

10.21203/rs.3.rs-123709/v1 ◽

2020 ◽

Author(s):

Marco Capogrosso ◽

Beatrice Barra ◽

Sara Conti ◽

Matthew Perich ◽

Katie Zhuang ◽

...

Keyword(s):

Spinal Cord ◽

Electrical Stimulation ◽

Motor Control ◽

Spinal Injury ◽

Cervical Spinal Cord ◽

Three Dimensional ◽

Sensory Afferents ◽

Reach And Grasp ◽

Cervical Spinal Injury ◽

Stimulation Of

Abstract Regaining arm motor control is critical for people with paralysis. Despite promising results on grasping, no technology could restore effective arm control. Here, we show that electrical stimulation of the cervical spinal cord enabled three monkeys with cervical spinal injury to execute functional arm movements. We designed an epidural interface that engaged surviving spinal circuits via the recruitment of large sensory afferents to produce movement. Simple stimulation bursts produced sustained joint movements which, triggered by movement-related intracortical signals, enabled monkeys with arm paralysis to perform an unconstrained, three-dimensional reach and grasp task. This restoration of voluntary motor control was enabled by the synergistic integration of spared descending commands and electrical stimulation within the spinal cord. The simplicity of this technology promises realistic clinical translation.

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Motor control strategies during bimanual isometric force control among healthy individuals

Adaptive Behavior ◽

10.1177/1059712318822737 ◽

2019 ◽

Vol 27 (2) ◽

pp. 127-136 ◽

Cited By ~ 2

Author(s):

Yan Jin ◽

Minhee Kim ◽

Sejun Oh ◽

BumChul Yoon

Keyword(s):

Young Adults ◽

Motor Control ◽

Control Strategy ◽

Force Control ◽

Isometric Force ◽

Control Strategies ◽

Force Variability ◽

Force Level ◽

Target Force ◽

Motor Synergy

This study aimed to provide a basic description of the motor control strategy during bimanual isometric force control in healthy young adults. Thirty healthy young adults (mean age: 27.4 ± 3.7 years) participated in the study. The subjects were instructed to press both hands simultaneously to match the target force level of 5%, 25%, and 50% bimanual maximum voluntary force using continuous visual feedback. Bimanual motor synergy and bimanual coordination, as well as force asymmetry, force accuracy, and force variability were compared. This study identified the specific motor control strategy of healthy young adults during bimanual isometric force control, indicating that they proportionally increased “good” and “bad” variabilities, resulting in comparable bimanual motor synergy as the target force level increased.

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4091 Influence of Vision and Proprioception on Motor Control in ASD

Journal of Clinical and Translational Science ◽

10.1017/cts.2020.303 ◽

2020 ◽

Vol 4 (s1) ◽

pp. 97-97

Author(s):

Robin L Shafer ◽

Zheng Wang ◽

Matthew W. Mosconi

Keyword(s):

Motor Control ◽

Visual Feedback ◽

Sensory Feedback ◽

Autism Spectrum ◽

Proprioceptive Feedback ◽

Tendon Vibration ◽

Force Output ◽

Preliminary Results ◽

Visual Gain ◽

Target Force

OBJECTIVES/GOALS: Sensorimotor integration deficits are common in Autism Spectrum Disorders (ASD). There is evidence for both an over-reliance on visual and proprioceptive feedback during motor control in ASD, suggesting deficits in the ability to modulate sensory feedback processing in order to use the most reliable input. This study aims to test this hypothesis. METHODS/STUDY POPULATION: 40 persons with ASD (ages 10-33 yrs) and 25 age-, sex- and nonverbal IQ-matched controls completed precision gripping tasks under multiple proprioceptive and visual feedback conditions. Participants squeezed a force sensor with their index finger and thumb and tried to match their force output to a target force. Visual feedback of the target force (stationary bar) and their force output (bar that moved up/down with increased/decreased force) were displayed on a computer screen. Visual feedback was presented across low, medium, and high gain levels; the force bar moved a greater distance per change in force at higher gains. Proprioceptive feedback was manipulated using 80Hz tendon vibration at the wrist to create an illusion that the muscle is contracted. Force regularity (approximate entropy; ApEn) was examined. RESULTS/ANTICIPATED RESULTS: We have scored data from 18 participants with ASD and 13 control participants to date. Preliminary results from these participants indicate a Group x Tendon Vibration x Visual Gain interaction for ApEn (F = 1.559, p = 0.023). Individuals with ASD show slight increases in ApEn with 80Hz tendon vibration relative to no tendon vibration in all visual conditions. Controls showed increased ApEn during 80Hz compared to no tendon vibration at low visual gain but decreased ApEn with tendon vibration at high visual gain. These preliminary results indicate that controls shift to using a secondary source of sensory feedback (e.g., proprioception) when the primary source (e.g., vision) is degraded. However, persons with ASD do not reweight different sensory feedback processes as feedback inputs are degraded or magnified. DISCUSSION/SIGNIFICANCE OF IMPACT: Our preliminary results reveal that sensorimotor issues in ASD result from deficits in the reweighting of sensory feedback. Namely, persons with ASD fail to dynamically recalibrate feedback processes across visual and proprioceptive systems when feedback conditions change. Our results may aid treatment development for sensorimotor issues in ASD.

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Sellick maneuver assisted real-time to achieve target force range in simulated environment—A prospective observational cross-sectional study on manikin

PLoS ONE ◽

10.1371/journal.pone.0227805 ◽

2020 ◽

Vol 15 (2) ◽

pp. e0227805

Author(s):

Hwan Ing Hee ◽

Chiong Ling Wong ◽

Olivia Wijeweera ◽

Rehena Sultana ◽

Ban Leong Sng

Keyword(s):

Real Time ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Simulated Environment ◽

Target Force ◽

Force Range

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A Measure of Motor Control at the Knee in Cerebral Palsy

Journal of Applied Biomechanics ◽

10.1123/jab.17.4.335 ◽

2001 ◽

Vol 17 (4) ◽

pp. 335-343 ◽

Cited By ~ 5

Author(s):

Jack R. Engsberg ◽

Joanne M. Wagner ◽

Angela K. Reitenbach ◽

Kevin W. Hollander ◽

John W. Standeven

Keyword(s):

Cerebral Palsy ◽

Motor Control ◽

Standard Deviation ◽

Knee Extension ◽

Knee Extensors ◽

Median Frequency ◽

Time Data ◽

Average Standard Deviation ◽

Small Magnitude ◽

Target Force

This investigation developed a measure of motor control for the knee extensors in adults with cerebral palsy (CP). Four adults with CP and 4 able-bodied (AB) adults participated. A KinCom dynamometer rotated the knee from approximately 90º of knee flexion to 10º/s less than the participant’s maximum knee extension at a speed of 10º/s, while the participant attempted to match a 44.5-N “target” force. The average, standard deviation, and median frequency of the force-time data were used to describe the test results. The individual force values for the AB group were near the target force and clustered together. The values for the CP group were also near the target force, but displayed greater variation. The average standard deviation for the CP group was more than three times larger than that of the AB group. The average median frequency for the CP group was less than that of the AB group. Results pointed to differing strategies for each group as they attempted to match the target force. The AB group attempted to match the target force with frequent small-magnitude force changes, while the CP group attempted to match the target force with fewer oscillations of greater magnitude. The methods employed in the present investigation are initial attempts to quantify one aspect of motor control, a visually guided tracking task.

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Motor control hierarchy in joint action that involves bimanual force production

Journal of Neurophysiology ◽

10.1152/jn.00313.2015 ◽

2015 ◽

Vol 113 (10) ◽

pp. 3736-3743 ◽

Cited By ~ 16

Author(s):

Junya Masumoto ◽

Nobuyuki Inui

Keyword(s):

Motor Control ◽

Joint Action ◽

Control Level ◽

Force Production ◽

Production Task ◽

Bimanual Action ◽

Target Force ◽

The Individual ◽

Complementary Strategy ◽

Force Production Task

The concept of hierarchical motor control has been viewed as a means of progressively decreasing the number of variables manipulated by each higher control level. We tested the hypothesis that turning an individual bimanual force-production task into a joint (two-participant) force-production task would lead to positive correlation between forces produced by the two hands of the individual participant (symmetric strategy) to enable negative correlation between forces produced by two participants (complementary strategy). The present study consisted of individual and joint tasks that involved both unimanual and bimanual conditions. In the joint task, 10 pairs of participants produced periodic isometric forces, such that the sum of forces that they produced matched a target force cycling between 5% and 10% of maximum voluntary contraction at 1 Hz. In the individual task, individuals attempted to match the same target force. In the joint bimanual condition, the two hands of each participant adopted a symmetric strategy of force, whereas the two participants adopted a complementary strategy of force, highlighting that the bimanual action behaved as a low level of a hierarchy, whereas the joint action behaved as an upper level. The complementary force production was greater interpersonally than intrapersonally. However, whereas the coherence was highest at 1 Hz in all conditions, the frequency synchrony was stronger intrapersonally than interpersonally. Moreover, whereas the bimanual action exhibited a smaller error and variability of force than the unimanual action, the joint action exhibited a less-variable interval and force than the individual action.

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