scholarly journals Anticipatory postural adjustments of lower limb muscles associated with voluntary contraction of the soleus mustle in standing man

1992 ◽  
Vol 37 (2) ◽  
pp. 145-158
Author(s):  
Kazutake Kawai ◽  
Tomoyoshi Komiyama ◽  
Tatsuya Kasai
Keyword(s):  
Lower Limb ◽  
Voluntary Contraction ◽  
Anticipatory Postural Adjustments ◽  
Postural Adjustments ◽  
Lower Limb Muscles ◽  
Limb Muscles

scholarly journals Corticospinal Excitability of the Lower Limb Muscles During the Anticipatory Postural Adjustments: A TMS Study During Dart Throwing

2021 ◽  
Vol 15 ◽  
Author(s):  
Amiri Matsumoto ◽  
Nan Liang ◽  
Hajime Ueda ◽  
Keisuke Irie
Keyword(s):  
Upper Limb ◽  
Lower Limb ◽  
Primary Motor Cortex ◽  
Anticipatory Postural Adjustments ◽  
Limb Movement ◽  
Corticospinal Excitability ◽  
Postural Adjustments ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Dart Throwing

Objective: To investigate whether the changes in the corticospinal excitability contribute to the anticipatory postural adjustments (APAs) in the lower limb muscles when performing the ballistic upper limb movement of the dart throwing.Methods: We examined the primary motor cortex (M1) excitability of the lower limb muscles [tibialis anterior (TA) and soleus (SOL) muscles] during the APA phase by using transcranial magnetic stimulation (TMS) in the healthy volunteers. The surface electromyography (EMG) of anterior deltoid, triceps brachii, biceps brachii, TA, and SOL muscles was recorded and the motor evoked potential (MEP) to TMS was recorded in the TA muscle along with the SOL muscle. TMS at the hotspot of the TA muscle was applied at the timings immediately prior to the TA onset. The kinematic parameters including the three-dimensional motion analysis and center of pressure (COP) during the dart throwing were also assessed.Results: The changes in COP and EMG of the TA muscle occurred preceding the dart throwing, which involved a slight elbow flexion followed by an extension. The correlation analysis revealed that the onset of the TA muscle was related to the COP change and the elbow joint flexion. The MEP amplitude in the TA muscle, but not that in the SOL muscle, significantly increased immediately prior to the EMG burst (100, 50, and 0 ms prior to the TA onset).Conclusion: Our findings demonstrate that the corticospinal excitability of the TA muscle increases prior to the ballistic upper limb movement of the dart throwing, suggesting that the corticospinal pathway contributes to the APA in the lower limb in a muscle-specific manner.

scholarly journals Inter-muscle differences in modulation of motor evoked potentials and posterior root-muscle reflexes evoked from lower-limb muscles during agonist and antagonist muscle contractions

2020 ◽  
Author(s):  
Akira Saito ◽  
Kento Nakagawa ◽  
Yohei Masugi ◽  
Kimitaka Nakazawa
Keyword(s):  
Lower Limb ◽  
Motor Evoked Potentials ◽  
Voluntary Contraction ◽  
Spinal Reflex ◽  
Posterior Root ◽  
Antagonist Muscle ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Agonist And Antagonist ◽  
Muscle Reflexes

AbstractVoluntary contraction facilitates corticospinal and spinal reflex circuit excitabilities of the contracted muscle and inhibits spinal reflex circuit excitability of the antagonist. It has been suggested that modulation of spinal reflex circuit excitability in agonist and antagonist muscles during voluntary contraction differs among lower-limb muscles. However, whether the effects of voluntary contraction on the excitabilities of corticospinal and spinal reflex circuits depend on the tested muscles remains unknown. The purpose of this study was to examine inter-muscle differences in modulation of the corticospinal and spinal reflex circuit excitabilities of multiple lower-limb muscles during voluntary contraction. Eleven young males performed isometric plantar-flexion, dorsi-flexion, knee extension, and flexion at low torque levels. Motor evoked potentials (MEPs) and posterior root-muscle reflexes from seven lower-leg and thigh muscles were evoked by transcranial magnetic stimulation and transcutaneous spinal cord stimulation, respectively, at rest and during weak voluntary contractions. MEP and posterior root-muscle reflex amplitudes of agonists were significantly increased as agonist torque level increased, except for the reflex of the tibialis anterior. MEP amplitudes of antagonists were significantly increased in relation to the agonist torque level, but those of the rectus femoris were slightly depressed during knee flexion. Regarding the posterior root-muscle reflex of the antagonists, the amplitudes of triceps surae and the hamstrings were significantly decreased, but those of the quadriceps femoris were significantly increased as the agonist torque level increased. These results demonstrate that modulation of corticospinal and spinal reflex circuit excitabilities during agonist and antagonist muscle contractions differed among lower-limb muscles.

scholarly journals Corticospinal-evoked responses in lower limb muscles during voluntary contractions at varying strengths

2008 ◽  
Vol 105 (5) ◽  
pp. 1527-1532 ◽  
Author(s):  
T. Oya ◽  
B. W. Hoffman ◽  
A. G. Cresswell
Keyword(s):  
Evoked Potentials ◽  
Upper Limb ◽  
Lower Limb ◽  
Motor Evoked Potentials ◽  
Voluntary Contraction ◽  
Medial Gastrocnemius ◽  
Evoked Responses ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Voluntary Contractions

This study investigated corticospinal-evoked responses in lower limb muscles during voluntary contractions at varying strengths. Similar investigations have been made on upper limb muscles, where evoked responses have been shown to increase up to ∼50% of maximal force and then decline. We elicited motor-evoked potentials (MEPs) and cervicomedullary motor-evoked potentials (CMEPs) in the soleus (Sol) and medial gastrocnemius (MG) muscles using magnetic stimulation over the motor cortex and cervicomedullary junction during voluntary plantar flexions with the torque ranging from 0 to 100% of a maximal voluntary contraction. Differences between the MEP and CMEP were also investigated to assess whether any changes were occurring at the cortical or spinal levels. In both Sol and MG, MEP and CMEP amplitudes [normalized to maximal M wave (Mmax)] showed an increase, followed by a plateau, over the greater part of the contraction range with responses increasing from ∼0.2 to ∼6% of Mmax for Sol and from ∼0.3 to ∼10% of Mmax for MG. Because both MEPs and CMEPs changed in a similar manner, the observed increase and lack of decrease at high force levels are likely related to underlying changes occurring at the spinal level. The evoked responses in the Sol and MG increase over a greater range of contraction strengths than for upper limb muscles, probably due to differences in the pattern of motor unit recruitment and rate coding for these muscles and the strength of the corticospinal input.

scholarly journals Effects of neuromuscular electrical stimulation and voluntary commands on the spinal reflex excitability of remote limb muscles

2019 ◽  
Vol 237 (12) ◽  
pp. 3195-3205 ◽  
Author(s):  
Tatsuya Kato ◽  
Atsushi Sasaki ◽  
Hikaru Yokoyama ◽  
Matija Milosevic ◽  
Kimitaka Nakazawa
Keyword(s):  
Electrical Stimulation ◽  
Upper Limb ◽  
Lower Limb ◽  
Neuromuscular Electrical Stimulation ◽  
Voluntary Contraction ◽  
Spinal Reflex ◽  
Sensory Level ◽  
Reflex Excitability ◽  
Lower Limb Muscles ◽  
Limb Muscles

Abstract It is well known that contracting the upper limbs can affect spinal reflexes of the lower limb muscle, via intraneuronal networks within the central nervous system. However, it remains unknown whether neuromuscular electrical stimulation (NMES), which can generate muscle contractions without central commands from the cortex, can also play a role in such inter-limb facilitation. Therefore, the objective of this study was to compare the effects of unilateral upper limb contractions using NMES and voluntary unilateral upper limb contractions on the inter-limb spinal reflex facilitation in the lower limb muscles. Spinal reflex excitability was assessed using transcutaneous spinal cord stimulation (tSCS) to elicit responses bilaterally in multiple lower limb muscles, including ankle and thigh muscles. Five interventions were applied on the right wrist flexors for 70 s: (1) sensory-level NMES; (2) motor-level NMES; (3) voluntary contraction; (4) voluntary contraction and sensory-level NMES; (5) voluntary contraction and motor-level NMES. Results showed that spinal reflex excitability of ankle muscles was facilitated bilaterally during voluntary contraction of the upper limb unilaterally and that voluntary contraction with motor-level NMES had similar effects as just contracting voluntarily. Meanwhile, motor-level NMES facilitated contralateral thigh muscles, and sensory-level NMES had no effect. Overall, our results suggest that inter-limb facilitation effect of spinal reflex excitability in lower limb muscles depends, to a larger extent, on the presence of the central commands from the cortex during voluntary contractions. However, peripheral input generated by muscle contractions using NMES might have effects on the spinal reflex excitability of inter-limb muscles via spinal intraneuronal networks.

Measurement and reproducibility of strength and voluntary activation of lower-limb muscles

2004 ◽  
Vol 29 (6) ◽  
pp. 834-842 ◽  
Author(s):  
Gabrielle Todd ◽  
Robert B. Gorman ◽  
Simon C. Gandevia
Keyword(s):  
Lower Limb ◽  
Voluntary Activation ◽  
Lower Limb Muscles ◽  
Limb Muscles
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