Microstimulation mapping of precentral cortex during trained movements

1990 ◽  
Vol 64 (6) ◽  
pp. 1668-1682 ◽  
Author(s):  
E. M. Schmidt ◽  
J. S. McIntosh
Keyword(s):  
Emg Activity ◽  
Cortical Region ◽  
Intracortical Microstimulation ◽  
Joint Movement ◽  
Wrist Flexion ◽  
Motoneuron Pool ◽  
Different Types ◽  
Muscle Inhibition ◽  
Forearm Muscle ◽  
Flexion And Extension

1. The precentral cortex of three Macaca mulatta monkeys were mapped with intracortical microstimulation (ICMS) while the monkeys performed alternating wrist flexion and extension movements. A forearm cocontraction task was also employed with one monkey. Electromyogram (EMG) recordings from forearm muscles were used to evaluate the results of ICMS. 2. We have found that the results of ICMS can be misleading if EMG activity is not recorded from the responding muscle. Inhibition can be interpreted as excitation if muscle palpation or joint movement are the only response criteria. 3. Movement of the stimulating electrode by as little as 200 microns in a single radial column sometimes changed EMG responses from inhibition to excitation or vice versa, indicating that cortical inhibitory areas for a muscle can be located very close to excitatory zones. 4. Both excitation and inhibition of muscles could be produced with ICMS of precentral cortex when the animal was performing a task involving the muscles being mapped. EMG responses to ICMS were stable, provided that the stimulation was applied at the same time during a repetitive task such that the motoneurons were at a given level of excitability. 5. Zones where ICMS produced inhibition of a particular forearm muscle were interspersed among zones that produced excitation for that muscle. 6. Regions exist in precentral cortex where ICMS activates antagonistic wrist muscles producing cocontraction. 7. The extensive cortical region from which any individual muscle can be activated or suppressed with ICMS and the various combinations of muscles that are activated from within this region suggest that different types of movements involving a single muscle are represented at different locations within this region. 8. At a few locations in precentral cortex, the EMG responses to ICMS were not just a function of the level of excitation of the motoneuron pool at the time of stimulation but were also dependent on the specific task the monkey was performing at the time of stimulation.

Combined effect of repetitive work and cold on muscle function and fatigue

2002 ◽  
Vol 92 (1) ◽  
pp. 354-361 ◽  
Author(s):  
Juha Oksa ◽  
Michel B. Ducharme ◽  
Hannu Rintamäki
Keyword(s):  
Muscle Function ◽  
Voluntary Contraction ◽  
Overuse Injuries ◽  
Emg Activity ◽  
Wrist Flexion ◽  
Fatigue Index ◽  
Local Cooling ◽  
Repetitive Work ◽  
Flexion Extension ◽  
Forearm Muscle

This study compared the effect of repetitive work in thermoneutral and cold conditions on forearm muscle electromyogram (EMG) and fatigue. We hypothesize that cold and repetitive work together cause higher EMG activity and fatigue than repetitive work only, thus creating a higher risk for overuse injuries. Eight men performed six 20-min work bouts at 25°C (W-25) and at 5°C while exposed to systemic (C-5) and local cooling (LC-5). The work was wrist flexion-extension exercise at 10% maximal voluntary contraction. The EMG activity of the forearm flexors and extensors was higher during C-5 (31 and 30%, respectively) and LC-5 (25 and 28%, respectively) than during W-25 ( P < 0.05). On the basis of fatigue index (calculated from changes in maximal flexor force and flexor EMG activity), the fatigue in the forearm flexors at the end of W-25 was 15%. The corresponding values at the end of C-5 and LC-5 were 37% ( P < 0.05 in relation to W-25) and 20%, respectively. Thus repetitive work in the cold causes higher EMG activity and fatigue than repetitive work in thermoneutral conditions.

scholarly journals Task-Dependent Modulation of Primary Afferent Depolarization in Cervical Spinal Cord of Monkeys Performing an Instructed Delay Task

2009 ◽  
Vol 102 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Kazuhiko Seki ◽  
Steve I. Perlmutter ◽  
Eberhard E. Fetz
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Cervical Vertebrae ◽  
Emg Activity ◽  
Active Movement ◽  
Primary Afferent Depolarization ◽  
Wrist Flexion ◽  
Primary Afferent ◽  
Tungsten Microelectrode ◽  
Flexion And Extension

Task-dependent modulation of primary afferent depolarization (PAD) was studied in the cervical spinal cord of two monkeys performing a wrist flexion and extension task with an instructed delay period. We implanted two nerve cuff electrodes on proximal and distal parts of the superficial radial nerve (SR) and a recording chamber over a hemi-laminectomy in the lower cervical vertebrae. Antidromic volleys (ADVs) in the SR were evoked by intraspinal microstimuli (ISMS, 3–10 Hz, 3–30 μA) applied through a tungsten microelectrode, and the area of each ADV was measured. In total, 434 ADVs were evoked by ISMS in two monkeys, with onset latency consistently shorter in the proximal than distal cuffs. Estimated conduction velocity suggest that most ADVs were caused by action potentials in cutaneous fibers originating from low-threshold tactile receptors. Modulation of the size of ADVs as a function of the task was examined in 281 ADVs induced by ISMS applied at 78 different intraspinal sites. The ADVs were significantly facilitated during active movement in both flexion and extension ( P < 0.05), suggesting an epoch-dependent modulation of PAD. This facilitation started 400–900 ms before the onset of EMG activity. Such pre-EMG modulation is hard to explain by movement-induced reafference and probably is associated with descending motor commands.

Response patterns and postspike effects of peripheral afferents in dorsal root ganglia of behaving monkeys

1992 ◽  
Vol 67 (4) ◽  
pp. 875-889 ◽  
Author(s):  
D. Flament ◽  
P. A. Fortier ◽  
E. E. Fetz
Keyword(s):  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
Emg Activity ◽  
Response Patterns ◽  
Forearm Muscles ◽  
Minimum Number ◽  
Peripheral Afferents ◽  
Behaving Monkeys ◽  
Forearm Muscle ◽  
Flexion And Extension

1. The activity of single afferent units was recorded in cervical dorsal root ganglia (DRG) in two macaque monkeys as they generated alternating flexion and extension torques about the wrist during a step-tracking task. During these isometric and auxotonic muscle contractions, electromyographic (EMG) activity was recorded with electrode pairs in up to 12 independent forearm muscles. Spike-triggered averages (STAs) of rectified EMG activity were used to identify afferents that were associated with correlated facilitation of active muscles. 2. Our aim was to find peripheral afferents producing postspike effects in muscles and to compare their properties with those of corticomotoneuronal (CM) and rubromotoneuronal (RM) cells previously obtained under identical behavioral conditions. We documented the timing, magnitude and distribution of their postspike facilitation (PSF) of forearm muscles and investigated the response properties of task-related units. 3. Of 125 afferent units tested with STAs, 68 showed PSF of EMG activity in at least one muscle. Fifty-nine DRG units provided sufficiently long recordings to generate averages with greater than or equal to 2,000 triggers, the minimum number considered to demonstrate reliable effects. Of these 59 units, 29 (49%) were associated with facilitation of forearm muscle activity. 4. Many STAs showed a gradual increase in EMG activity starting before or near the afferent trigger spike; often superimposed on this broad facilitation was a sharply rising PSF starting at a longer latency. The earliest poststimulus facilitation evoked by single microstimuli delivered in DRG occurred in stimulus-triggered averages at a latency of 3.5 ms. In STAs the broad facilitation beginning at latencies shorter than the responses to electrical stimulation was attributed to synchronous discharges in other afferent units. The sharper postspike EMG increases occurring with latencies of greater than or equal to 3.5 ms were identified as PSF produced by the afferent. The PSF parameters documented in this study were measured after subtracting the effects of synchrony facilitation. 5. PSF of EMG activity began at a mean latency of 5.8 +/- 0.3 (SE) ms and peaked at a mean latency of 7.5 +/- 0.3 (SE) ms. In previous studies, the PSFs from CM and RM cells had mean onset latencies of 6.3 and 5.6 ms, respectively, and mean peak latencies of 10.2 and 9.1 ms. 6. A measure of the PSF amplitude is the mean percent increase (MPI), defined as the increase of the PSF above its base measured as a percentage of the prespike baseline mean.(ABSTRACT TRUNCATED AT 400 WORDS)

Application Study on Finger Joint Motion in Rehabilitation Training

2014 ◽  
Vol 644-650 ◽  
pp. 879-883
Author(s):  
Jing Jing Yu
Keyword(s):  
Control Method ◽  
Finger Joint ◽  
Continuous Passive Motion ◽  
Joint Motion ◽  
Joint Movement ◽  
Rehabilitation Training ◽  
Angle Data ◽  
Finger Flexion ◽  
And Control ◽  
Flexion And Extension

In various forms of movement of finger rehabilitation training, Continuous Passive Motion (CPM) of single degree of freedom (1 DOF) has outstanding application value. Taking classic flexion and extension movement for instance, this study collected the joint angle data of finger flexion and extension motion by experiments and confirmed that the joint motion of finger are not independent of each other but there is certain rule. This paper studies the finger joint movement rule from qualitative and quantitative aspects, and the conclusion can guide the design of the mechanism and control method of finger rehabilitation training robot.

Modeling the resistance mechanism of passive knee joint flexion and extension for use in rehabilitation equipment

2021 ◽  
pp. 095441192199013
Author(s):  
Mansoor Amiri ◽  
Farhad Tabatabai Ghomsheh ◽  
Farshad Ghazalian
Keyword(s):  
Knee Joint ◽  
Sagittal Plane ◽  
Resistance Mechanism ◽  
Time Dependent ◽  
Coefficient Of Determination ◽  
Joint Movement ◽  
Elastic Coefficient ◽  
Knee Movement ◽  
Joint Flexion ◽  
Flexion And Extension

The purpose of this study was to model the resistance mechanism of Passive Knee Joint Flexion and Extension to create a similar torque mechanism in rehabilitation equipment. In order to better model the behavior of passive knee tissues, it is necessary to exactly calculate the two coefficients of elasticity of time-independent and time-dependent parts. Ten healthy male volunteers (mean height 176.4+/−4.59 cm) participated in this study. Passive knee joint flexion and extension occurred at velocities of 15, 45, and 120 (degree/s), and in five consecutive cycles and within the range of 0 to 100° of knee movement on the sagittal plane on Cybex isokinetic dynamometer. To ensure that the muscles were relaxed, the electrical activity of knee muscles was recorded. The elastic coefficient, (KS) increased with elevating the passive velocity in flexion and extension. The elastic coefficient, (KP) was observed to grow with the passive velocity increase. While, the viscous coefficient (C) diminished with passive velocity rise in extension and flexion. The heightened passive velocity of the motion resulted in increased hysteresis (at a rate of 42%). The desired of passive velocity is lower so that there is less energy lost and the viscoelastic resistance of the tissue in the movement decreases. The Coefficient of Determination, R2 between the model-responses and experimental curves in the extension was 0.96 < R2 < 0.99 and in flexion was 0.95 < R2 < 0.99. This modeling is capable of predicting the true performance of the components of passive knee movement and we can create a resistance mechanism in the rehabilitation equipment to perform knee joint movement. Quantitative measurements of two elastic coefficients of Time-independent and Time-dependent parts passive knee joint coefficients should be used for better accurate simulation the behavior of passive tissues in the knee which is not seen in other studies.

Detection of effort maximality in adults performing isokinetic wrist flexion and extension

2021 ◽  
pp. 1-7
Author(s):  
Mercè Torra ◽  
Eduard Pujol ◽  
Anna Maiques ◽  
Salvador Quintana ◽  
Roser Garreta ◽  
...  
Keyword(s):  
High Velocity ◽  
Healthy Male ◽  
Wrist Flexion ◽  
Low Velocity ◽  
Wrist Extensor ◽  
Submaximal Effort ◽  
The Difference ◽  
Muscle Groups ◽  
Maximal Effort ◽  
Flexion And Extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

Traumatic Brachial Plexus Palsy in Children: Long-Term Outcome and Strategy of Reconstruction

2021 ◽  
Author(s):  
Tarek A. El-Gammal ◽  
Amr El-Sayed ◽  
Mohamed M. Kotb ◽  
Waleed Riad Saleh ◽  
Yasser Farouk Ragheb ◽  
...  
Keyword(s):  
Brachial Plexus ◽  
External Rotation ◽  
Hand Function ◽  
Functional Restoration ◽  
Shoulder Abduction ◽  
Wrist Flexion ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Age At Surgery ◽  
Flexion And Extension

Abstract Background Traumatic brachial plexus injuries in children represent a definite spectrum of injuries between adult and neonatal brachial plexus injuries. Their characteristics have been scarcely reported in the literature. The priority of functional restoration is not clear. Materials and Methods In total, 52 children with surgically treated traumatic brachial plexus injuries, excluding Erb's palsy, were reviewed after a minimum follow-up of 2 years. All children except nine were males, with an average age at surgery of 8 years. Forty-five children had exclusive supraclavicular plexus injuries. Twenty-one of them (46%) had two or more root avulsions. Seven children (13.5%) had infraclavicular plexus injuries. Time from trauma to surgery varied from 1 to 15 months (mean = 4.7 months). Extraplexal neurotization was the most common surgical technique used. Results Shoulder abduction and external rotation were restored to an average of 83 and 26 degrees, respectively. Elbow flexion and extension were restored to grade ≥3 in 96 and 91.5% of cases, respectively. Finger flexion and extension were restored to grade ≥4 in 29 and 32% of cases, respectively. Wrist flexion and extension were restored to grade ≥4 in 21 and 27% of cases, respectively. Results of neurotization were superior to those of neurolysis and nerve grafting. Among the 24 children with insensate hands, 20 (83.3%) recovered S3 sensation, 3 recovered S2, and 1 recovered S1. No case complained of neuropathic pain. Functional recovery correlated negatively but insignificantly with the age at surgery and time from injury to surgery. Conclusion Brachial plexus injuries in children are associated with a high incidence root avulsions and no pain. Neurotization is frequently required and the outcome is not significantly affected by the delay in surgery. In total plexus injuries, some useful hand function can be restored, and management should follow that of obstetric palsy and be focused on innervating the medial cord.

scholarly journals Joint-Specific Play Controller for Upper Extremity Therapy: Feasibility Study in Children With Wrist Impairment

2016 ◽  
Vol 96 (11) ◽  
pp. 1773-1781
Author(s):  
Bethany J. Wilcox ◽  
Megan M. Wilkins ◽  
Benjamin Basseches ◽  
Joel B. Schwartz ◽  
Karen Kerman ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Computer Games ◽  
Average Frequency ◽  
Cross Sectional Study ◽  
Wrist Flexion ◽  
Motor Impairments ◽  
Cross Sectional ◽  
Play Activity ◽  
Play Session ◽  
Flexion And Extension

Abstract Background Challenges with any therapeutic program for children include the level of the child's engagement or adherence. Capitalizing on one of the primary learning avenues of children, play, the approach described in this article is to develop therapeutic toy and game controllers that require specific and repetitive joint movements to trigger toy/game activation. Objective The goal of this study was to evaluate a specially designed wrist flexion and extension play controller in a cohort of children with upper extremity motor impairments (UEMIs). The aim was to understand the relationship among controller play activity, measures of wrist and forearm range of motion (ROM) and spasticity, and ratings of fun and difficulty. Design This was a cross-sectional study of 21 children (12 male, 9 female; 4–12 years of age) with UEMIs. Methods All children participated in a structured in-clinic play session during which measurements of spasticity and ROM were collected. The children were fitted with the controller and played with 2 toys and 2 computer games for 5 minutes each. Wrist flexion and extension motion during play was recorded and analyzed. In addition, children rated the fun and difficulty of play. Results Flexion and extension goal movements were repeatedly achieved by children during the play session at an average frequency of 0.27 Hz. At this frequency, 15 minutes of play per day would result in approximately 1,700 targeted joint motions per week. Play activity was associated with ROM measures, specifically supination, but toy perception ratings of enjoyment and difficulty were not correlated with clinical measures. Limitations The reported results may not be representative of children with more severe UEMIs. Conclusions These outcomes indicate that the therapeutic controllers elicited repetitive goal movements and were adaptable, enjoyable, and challenging for children of varying ages and UEMIs.

scholarly journals Duration of Short-term Effects of PNF According to Different Types of Joint Movement

2012 ◽  
Vol 27 (5) ◽  
pp. 589-592
Author(s):  
Katsuyuki KATOU ◽  
Hitoshi MARUYAMA
Keyword(s):  
Joint Movement ◽  
Short Term ◽  
Different Types ◽  
Short Term Effects

Assessment of Muscle Activity and Joint Angles in Small-Handed Pianists: A Pilot Study on the 7/8-Sized Keyboard versus the Full-Sized Keyboard

2006 ◽  
Vol 21 (1) ◽  
pp. 3-9
Author(s):  
B G Wristen ◽  
M C Jung ◽  
A K G Wismer ◽  
M S Hallbeck
Keyword(s):  
Pilot Study ◽  
Research Question ◽  
Wrist Flexion ◽  
Joint Angles ◽  
Ulnar Deviation ◽  
Surface Electrodes ◽  
Musical Excerpt ◽  
Muscle Loading ◽  
Maximal Angle ◽  
Flexion And Extension

This pilot study examined whether the use of a 7/8 keyboard contributed to the physical ease of small-handed pianists as compared with the conventional piano keyboard. A secondary research question focused on the progression of physical ease in pianists making the transition from one keyboard to the other. For the purposes of this study, a hand span of 8 inches or less was used to define a “small-handed” pianist. The goal was to measure muscle loading and hand span during performance of a specified musical excerpt. For data collection, each of the two participants was connected to an 8-channel electromyography system via surface electrodes, which were attached to the upper back/shoulder, parts of the hand and arm, and masseter muscle of the jaw. Subjects also were fitted with electrogoniometers to capture how the span from the first metacarpophalangeal (MCP) joint to the fifth MCP joint moves according to performance demands, as well as wrist flexion and extension and radial and ulnar deviation. We found that small-handed pianists preferred the smaller keyboard and were able to transition between it and the conventional keyboard. The maximal angle of hand span while playing a difficult piece was about 5º smaller radially and 10º smaller ulnarly for the 7/8 keyboard, leading to perceived ease and better performance as rated by the pianists.

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