scholarly journals Effects of muscle action type on corticospinal excitability and triceps surae muscle-tendon mechanics

2018 ◽  
Vol 119 (2) ◽  
pp. 563-572 ◽  
Author(s):  
P. Valadão ◽  
S. Kurokawa ◽  
T. Finni ◽  
J. Avela
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Pennation Angle ◽  
H Reflex ◽  
Corticospinal Excitability ◽  
Triceps Surae ◽  
Fascicle Length ◽  
The Central Nervous System ◽  
Muscle Actions

This study investigated whether the specific motor control strategy reported for eccentric muscle actions is dependent on muscle mechanical behavior. Motor evoked potentials, Hoffman reflex (H-reflex), fascicle length, pennation angle, and fascicle velocity of soleus muscle were compared between isometric and two eccentric conditions. Ten volunteers performed maximal plantarflexion trials in isometric, slow eccentric (25°/s), and fast eccentric (100°/s) conditions, each in a different randomized testing session. H-reflex normalized by the preceding M wave (H/M) was depressed in both eccentric conditions compared with isometric ( P < 0.001), while no differences in fascicle length and pennation angle were found among conditions. Furthermore, although the fast eccentric condition had greater fascicle velocity than slow eccentric ( P = 0.001), there were no differences in H/M. There were no differences in motor evoked potential size between conditions, and silent period was shorter for both eccentric conditions compared with isometric ( P = 0.009). Taken together, the present results corroborate the hypothesis that the central nervous system has an unique activation strategy during eccentric muscle actions and suggest that sensory feedback does not play an important role in modulating these muscle actions. NEW & NOTEWORTHY The present study provides new insight into the motor control of eccentric muscle actions. It was demonstrated that task-dependent corticospinal excitability modulation does not seem to depend on sensory information processing. These findings support the hypothesis that the central nervous system has a unique activation strategy during eccentric muscle actions.

Anticipatory postural mechanisms: Some evidence and methodological implications

1996 ◽  
Vol 19 (1) ◽  
pp. 77-78
Author(s):  
Tatsuya Kasai
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Postural Control ◽  
H Reflex ◽  
Human Motor Control ◽  
Therapeutic Implications ◽  
Anticipatory Postural Control ◽  
The Central Nervous System ◽  
Human Motor

AbstractTo understand the basic priorities of the central nervous system in human motor control, neurophysiological parameters are important. Certain H-reflex methods related to anticipatory postural control are particularly useful and may have therapeutic implications.

Long Latency Reflexes and the Silent Period

2009 ◽  
pp. 543-550
Author(s):  
John N. Caviness
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Brain Stem ◽  
Silent Period ◽  
Complex Interplay ◽  
Long Latency ◽  
System P ◽  
The Central Nervous System ◽  
Long Latency Reflexes

LLRs and the silent period are EMG phenomena that reflect the complex interplay of spinal, brain stem, and cortical influences in motor control. These techniques have been applied to the study of disorders of motor control such as Parkinson’s disease, Huntington’s disease, and dystonia. Abnormalities of these reflexes may help to detect lesions of the central nervous system.

Investigation of central motor pathways: magnetic brain stimulation

2010 ◽  
pp. 4782-4785
Author(s):  
K.R. Mills
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Early Diagnosis ◽  
Lower Limb ◽  
Neurological Disease ◽  
Cranial Nerves ◽  
Motor Pathways ◽  
The Central Nervous System ◽  
Abnormal Motor

The ability to percutaneously stimulate the central nervous system of awake humans without causing pain has opened up new areas for neurophysiological investigation in the early diagnosis of neurological disease, also furthered the understanding of normal and abnormal motor control. Magnetic stimulators are now available that can excite both upper and lower limb areas of the motor cortex, as well as cranial nerves, motor roots, and deeply sited peripheral nerves....

Idiopathic Scoliosis and the Central Nervous System: A Motor Control Problem

Spine ◽  
1985 ◽  
Vol 10 (1) ◽  
pp. 1-14 ◽  
Author(s):  
RICHARD HERMAN ◽  
JAMES MIXON ◽  
ANNE FISHER ◽  
RUTH MAULUCCI ◽  
JOSEPH STUYCK
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Idiopathic Scoliosis ◽  
Control Problem ◽  
System A ◽  
The Central Nervous System

Segregation of agonist and antagonist systems minimizes the benefits of polarity

1997 ◽  
Vol 20 (2) ◽  
pp. 315-316
Author(s):  
William A. MacKay
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Lateral Inhibition ◽  
Explanatory Power ◽  
Physiological Mechanisms ◽  
Kinematic Theory ◽  
Agonist And Antagonist ◽  
The Central Nervous System

A purely kinematic theory of movement runs the risk of having no explanatory power because it neglects the internal generative structures of the central nervous system. Distributed interaction between the agonist and antagonist systems would better simulate physiological mechanisms of oscillation, lateral inhibition, and synchronization, all of which have important roles in motor control.

scholarly journals Impaired neuro-motor control in chronic whiplash and tension-type headache

2021 ◽  
Author(s):  
Jens Astrup ◽  
Finn Gyntelberg ◽  
Anne-Marie Johansen ◽  
Anders Lei ◽  
Jacob Louis Marott
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Reference Point ◽  
Tension Type Headache ◽  
Head Movements ◽  
Laser Tracking ◽  
The Central Nervous System ◽  
Type Headache ◽  
Chronic Whiplash

Abstract BackgroundThe purpose of this study is to support the hypothesis that the neuro-motor control of the neck muscles is impaired in the diseases of chronic whiplash and tension-type headache. This hypothesis is based on a previous study, and if confirmed, it indicates that the central nervous system may be part of the pathophysiology of these diseases. For further verification, we designed a laser tracking method for standardized and quantitative measurements of movements of head and hand. The hand was included as a presumed normal reference to the head movements.MethodsA new laser tracking instrument was designed to monitor the ability of a test-person to track a reference point on the wall by a laser fixed to the forehead or held in the hand. The reference point moves in runs of a circle or a square at three different speeds 10, 20 or 30 cm/sec thus providing 6 runs for both head and hand per test-person. We used a 1x1x1 m set-up geometry. The data of each run was processed on-line. Groups of 22 patients diagnosed with chronic whiplash associated disorder, 19 patients diagnosed with chronic tension-type headache and 37 control persons were compared.FindingsA small but highly significant dyscoordination of head movements was observed in both patients groups, and in whiplash also of the hand. InterpretationOur study confirms the hypothesis that the neuro-motor control of the neck muscles is impaired in both chronic whiplash and tension-type headache. In our view this observation implicates that the central nervous system may be involved in the primary pathology of both these diseases. Accordingly, we suggest a provisional term 'cervical dyssynergia' for these diseases, and suggest further studies along this paradigm.

scholarly journals When 90% of the variance is not enough: residual EMG from muscle synergy extraction influences task performance

2020 ◽  
Vol 123 (6) ◽  
pp. 2180-2190 ◽  
Author(s):  
Victor R. Barradas ◽  
Jason J. Kutch ◽  
Toshihiro Kawase ◽  
Yasuharu Koike ◽  
Nicolas Schweighofer
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Dimensionality Reduction ◽  
Task Performance ◽  
Muscle Activity ◽  
Muscle Synergy ◽  
Systematic Effect ◽  
Extraction Techniques ◽  
The Central Nervous System

The muscle synergy hypothesis posits that the central nervous system simplifies motor control by grouping muscles into modules. Current techniques use dimensionality reduction, such that the identified synergies reconstruct 90% of the muscle activity. We show that residual muscle activity following such identification can have a large systematic effect on movements, even when the number of synergies approaches the number of muscles. Current synergy extraction techniques must therefore be updated to identify true physiological synergies.

scholarly journals Evidence of adaptations of locomotor neural drive in response to enhanced intermuscular connectivity between the triceps surae muscles of the rat

2017 ◽  
Vol 118 (3) ◽  
pp. 1677-1689 ◽  
Author(s):  
Michel Bernabei ◽  
Jaap H. van Dieën ◽  
Huub Maas
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Muscle Activation ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Connective Tissues ◽  
Muscle Belly ◽  
The Central Nervous System ◽  
Triceps Surae Muscles ◽  
Gastrocnemius Muscles

The aims of this study were to investigate changes 1) in the coordination of activation of the triceps surae muscle group, and 2) in muscle belly length of soleus (SO) and lateral gastrocnemius (LG) during locomotion (trotting) in response to increased stiffness of intermuscular connective tissues in the rat. We measured muscle activation and muscle belly lengths, as well as hindlimb kinematics, before and after an artificial enhancement of the connectivity between SO and LG muscles obtained by implanting a tissue-integrating surgical mesh at the muscles’ interface. We found that SO muscle activation decreased to 62%, while activation of LG and medial gastrocnemius muscles increased to 134 and 125%, respectively, compared with the levels measured preintervention. Although secondary additional or amplified activation bursts were observed with enhanced connectivity, the primary pattern of activation over the stride and the burst duration were not affected by the intervention. Similar muscle length changes after manipulation were observed, suggesting that length feedback from spindle receptors within SO and LG was not affected by the connectivity enhancement. We conclude that peripheral mechanical constraints given by morphological (re)organization of connective tissues linking synergists are taken into account by the central nervous system. The observed shift in activity toward the gastrocnemius muscles after the intervention suggests that these larger muscles are preferentially recruited when the soleus has a similar mechanical disadvantage in that it produces an unwanted flexion moment around the knee. NEW & NOTEWORTHY Connective tissue linkages between muscle-tendon units may act as an additional mechanical constraint on the musculoskeletal system, thereby reducing the spectrum of solutions for performing a motor task. We found that intermuscular coordination changes following intermuscular connectivity enhancement. Besides showing that the extent of such connectivity is taken into account by the central nervous system, our results suggest that recruitment of triceps surae muscles is governed by the moments produced at the ankle-knee joints.

Sign in / Sign up

Export Citation Format

Share Document