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Effects of changing wrist positions on finger flexor hypertonia in stroke survivors

Sheng Li, Derek G. Kamper, William Zev Rymer
2006 Muscle and Nerve  
In 12 stroke survivors, we recorded torque and electromyographic (EMG) responses of extrinsic finger flexors to constant-velocity rotation of the metacarpophalangeal (MCP) joints of the affected hand,  ...  Muscle length changes were imposed by changing wrist angle between 0°, 25°, and 50°of flexion.  ...  The baseline EMG (EMG BG ) was estimated from the first 200 ms of the trial, prior to initiation of the stretch, 17 and the reflex EMG activity was estimated from a 100-ms window centered on the peak EMG  ... 
doi:10.1002/mus.20453 pmid:16270306 fatcat:mzcsi62b6zf5bbbpw5na74wula

Changes in the Neural and Non-neural Related Properties of the Spastic Wrist Flexors After Treatment With Botulinum Toxin A in Post-stroke Subjects: An Optimization Study

Ruoli Wang, Johan Gäverth, Pawel A. Herman
2018 Frontiers in Bioengineering and Biotechnology  
Data of joint angle and resistant torque were collected from 21 chronic stroke patients before, and 4 and 12 weeks post BoTN-A injection using NeuroFlexor, which is a motorized force measurement device  ...  The decreased neural component was mainly due to the increased motoneuron pool threshold, which is interpreted as a net excitatory and inhibitory inputs to the motoneuron pool.  ...  The hand rested on the platform with the metacarpophalangeal joints in slight flexion and the fingers fully extended.  ... 
doi:10.3389/fbioe.2018.00073 pmid:29963551 pmcid:PMC6013585 fatcat:a3rivy5ij5hx7jlule57lhdlua

Functional properties of human muscle spindles

Vaughan G. Macefield, Thomas P. Knellwolf
2018 Journal of Neurophysiology  
Modulation of human muscle spindle discharge by arterial pulsations-functional effects and consequences. PLoS One 7: e35091, 2012. doi:10.1371/journal.pone.0035091.  ...  The effects of experimental muscle and skin pain on the static stretch sensitivity of human muscle spindles in relaxed leg muscles.  ...  It can be seen that the spindle discharge approximated the sinusoidal changes in joint angle and muscle fascicle length and velocity.  ... 
doi:10.1152/jn.00071.2018 pmid:29668385 fatcat:cyo7ztbqvjewjjalweqhzrhb7a

Correlation between tremor, voluntary contraction, and firing pattern of motor units in Parkinson's disease

V. Dietz, W. Hillesheimer, H. -J. Freund
1974 Journal of Neurology, Neurosurgery and Psychiatry  
Both changes are the consequence of increasing discharge rates of motoneurones at stronger contractions.  ...  SYNOPSIS Patients with tremor of Parkinsonism show three characteristics of motor unit activity: rhythmic spontaneous resting discharge, abnormally low firing rates during voluntary contraction, and consistent  ...  This seems reasonable on the basis of the relationship between tremor and discharge rate of the motoneurone.  ... 
doi:10.1136/jnnp.37.8.927 pmid:4419618 pmcid:PMC494807 fatcat:gq2uersp4rhrzgdlse6q4pf4da

Position Sensitivity of Feline Paraspinal Muscle Spindles to Vertebral Movement in the Lumbar Spine

Dong-Yuan Cao, Joel G. Pickar, Weiginq Ge, Allyson Ianuzzi, Partap S. Khalsa
2009 Journal of Neurophysiology  
This angle was estimated from measurements of facet joint capsule strain (FJC) based on a previously established relationship between IVA and FJC strain in the cat lumbar vertebral column during lumbar  ...  To enable comparisons with appendicular muscle spindles where joint angle was measured, we also calculated sensitivity in terms of the L 6 and L 7 intervertebral flexion angle (IVA).  ...  Linear position sensitivity based on muscle length using the random coefficient mixed model was 19.5 imp⅐ s Ϫ1 ⅐mm Ϫ1 [12.7, 26.2 (CI), P Ͻ 0.001], 20% greater than the sensitivity estimate based on vertebral  ... 
doi:10.1152/jn.90976.2008 pmid:19164108 pmcid:PMC2695637 fatcat:tysmcflk5jh5vcrfz3ukrt7hru

Effect of Muscle Biomechanics on the Quantification of Spasticity

D. G. Kamper, B. D. Schmit, W. Z. Rymer
2001 Annals of Biomedical Engineering  
Estimates of biomechanical parameters were used to convert measured reflex joint torque and joint angle into composite flexor muscle stress and stretch.  ...  The muscles were initially passive, with the joint placed in a midrange position.  ...  This software provides data for musculotendon length and moment arm as functions of joint angles, based on geometry.  ... 
doi:10.1114/1.1424918 pmid:11853265 fatcat:vro7d5maj5gvnkbks7bk7cfxmi

Table of Contents

2020 IEEE journal of biomedical and health informatics  
Angle Estimation Based on Motoneuron Discharge Activities . . . . . . . . . . . . . . . . . . . . . . . . . .C. Dai and X.  ...  Bodanese 747 Finger Joint . . . . . . . . . . . . . . . . . . . . . . . . . . . . E. T. Martinez, M. Leyva-Vallina, Md. M. K. Sarker, D. Puig, N. Petkov, and P. Radeva 866 A . . . . . . . . Y.  ... 
doi:10.1109/jbhi.2020.2970851 fatcat:nsr4pr6wwzfbhpl23hvwlccjra

Primate motor cortex and free arm movements to visual targets in three- dimensional space. I. Relations between single cell discharge and direction of movement

AB Schwartz, RE Kettner, AP Georgopoulos
1988 Journal of Neuroscience  
The preferred direction estimated as described above was based on discharge rates averaged over S-8 repetitions.  ...  The CUSUM crossed the upper boundary on the 7th bin, which gives an estimate of 140 msec as the latency of increase in cell activity.  ... 
doi:10.1523/jneurosci.08-08-02913.1988 pmid:3411361 fatcat:rgb7mmhuqfhg5bjhtbjv3tkgvi

The Effect of Motor Imagery on Spinal Segmental Excitability

S. Li
2004 Journal of Neuroscience  
The purpose of this study was to investigate the effect of motor imagery on spinal segmental excitability by recording the reflex responses to externally applied stretch of the extrinsic finger flexors  ...  These observations support the view that effects must have been mediated by imagery-related subthreshold activation of spinal motoneurons and/or interneurons, rather than by long-latency transcortical  ...  To estimate the latency of monosynaptic pathways to motoneurons innervating finger flexors, tendon tap tests were performed in three randomly selected subjects.  ... 
doi:10.1523/jneurosci.2781-04.2004 pmid:15509755 fatcat:pfaxbv2gmjfopmwlmuxvdxlz3i

Toward contextual instead of either/or thinking

Mario Wiesendanger
1978 Behavioral and Brain Sciences  
It is possible that there exist separate cortical projection areas for kinaesthetic signals from muscles and from joints.  ...  for joint angle However, Skoglund's findings of joint afferents that discharge at intermediate joint angles have not been confirmed Clark, 1969 op cit, Clark, 1975; Clark and Burgess, 1975op cit , Grigg  ...  in the PAN that discharge at intermediate angles Furthermore, the sense of joint position in the hip (Grigg, Finerman, and Riley, 1973) and finger (Cross and McCloskey, 1973 op cit) have been shown  ... 
doi:10.1017/s0140525x00060386 fatcat:xjcs7oqojnht3nwjqulytfdzp4

New insights into the pathophysiology of post-stroke spasticity

Sheng Li, Gerard E. Francisco
2015 Frontiers in Human Neuroscience  
Spasticity is one of many consequences after stroke. It is characterized by a velocity-dependent increase in resistance during passive stretch, resulting from hyperexcitability of the stretch reflex.  ...  The severity of sternocleidomastoid muscle spasticity could be estimated based on abnormality of head posture.  ...  This new balance could be reflected by a change in the resting angle of a joint, i.e., the more spastic the muscle is, the more abnormal resting angle the involved joint maintains.  ... 
doi:10.3389/fnhum.2015.00192 pmid:25914638 pmcid:PMC4392691 fatcat:tsypmmeklbbatcp3hhdmtmrpka

The potential for understanding the synaptic organization of human motor commands via the firing patterns of motoneurons

Michael D. Johnson, Christopher K. Thompson, Vicki M. Tysseling, Randall K. Powers, Charles J. Heckman
2017 Journal of Neurophysiology  
The potential for understanding the synaptic organization of human motor commands via the firing patterns of motoneurons.  ...  based on recordings of the discharge of multiple motor units.  ...  This detection is in fact achievable, via two approaches, one based on rate modulation and one on recruitment.  ... 
doi:10.1152/jn.00018.2017 pmid:28356467 pmcid:PMC5511870 fatcat:f4ur3hsedzddlm5uyrnikk2uli

Significant Roles of Synergistic Muscles in Human Redundant and Complicated Activities

Motoki Kouzaki
2005 International Journal of Sport and Health Science  
On the basis of a perspective with an emphasis on synergistic relations, I suggest that the different roles of these muscles, which are neurophysiologically regulated, make it possible to control human  ...  This brief review, therefore, proposes three topics that examine the significant roles of synergistic muscles: 1) task-dependent neural activities are modulated by peripheral afferent activities as well  ...  Previous studies dealing with task-related activities among muscles have also indicated that the relative activation between the elbow flexor muscles depends on the elbow joint angle (Hansan & Enoka,  ... 
doi:10.5432/ijshs.3.181 fatcat:xxo4njsgdngrbpgmzfo6hkkta4

High-frequency submaximal stimulation over muscle evokes centrally generated forces in human upper limb skeletal muscles

Jean-Sébastien Blouin, Lee D. Walsh, Peter Nickolls, Simon C. Gandevia
2009 Journal of applied physiology  
Motoneurons of human lower limb muscles exhibit sustained, submaximal activity to high-frequency electrical trains, which has been hypothesized to be partly triggered by monosynaptic Ia afferents.  ...  Control of posture and movement requires control of the output from motoneurons.  ...  This technique is based on the assumption that 1) synaptic currents can be estimated by the instantaneous firing frequency of a low-threshold motor Fig. 6 .  ... 
doi:10.1152/japplphysiol.90939.2008 pmid:19008485 fatcat:n6hwgmqijjbivafen5gudcqjyu

Distinct sensorimotor feedback loops for dynamic and static control of primate precision grip [article]

Tomomichi Oya, Tomohiko Takei, Kazuhiko Seki
2019 bioRxiv   pre-print
We investigated the neuronal interactions between the spinal cord and forelimb muscles, and the motor cortex and the muscles, with an emphasis on their modulation during dynamic and static phase of grasping  ...  While macaque monkeys were performing a precision grip comprising dynamic and static phases, we recorded spinal or cortical local field potentials simultaneously with electromyographic activity, thereafter  ...  lag estimation, the coherent pattern was putatively attributed to 197 motoneuron pool activity (Takei and Seki, 2008).  ... 
doi:10.1101/640201 fatcat:vs5s35dzcrdeddppdytmq33xhe
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