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.

Validity of Skeletal Muscle Ultrasound in Assessment of Suspected Limb Girdle Muscular Dystrophy Patients

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Rasha M Ibrahim ◽  
Haitham M Hamdy ◽  
Amr A Mohammed ◽  
Ahmed M Elsadek ◽  
Ahmed M Bassiouny ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Upper Limb ◽  
Lower Limb ◽  
Limb Girdle Muscular Dystrophy ◽  
Ultrasound Images ◽  
General Electric ◽  
Cross Sectional ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Muscle Ultrasound

Abstract Background Limb-girdle muscular dystrophies (LGMDs) are a clinically and genetically heterogeneous group of disorders characterized by progressive muscle weakness and degenerative muscle changes. Studies have shown that ultrasound can be useful both for diagnosis and follow-up of LGMDs patients. Objectives This study aims to measure the sensitivity and the specificity of muscle ultrasound in assessment of suspected limb girdle muscular dystrophy patients. Subjects and Methods This cross-sectional descriptive study was conducted on Fifty-five patients with suspected LGMD from neuromuscular unit, myology clinic, Ain Shams University hospitals and eight healthy subjects. Age was above 2 years. Both sexes were included in the study. They underwent real-time B-mode ultrasonography performed with using Logiq p9 General Electric ultrasound machine and General Electric 7-11.5 MHZ linear array ultrasound probe. All ultrasound images have been obtained and scored by a single examiner and muscle echo intensity was visually graded semiquantitative according to Heckmatt's scale. The examiner was blinded to the muscle biopsy results and clinical evaluations. Results Statistical analysis revealed that the diagnostic performance of muscle US (Heckmatt’s score) in LGMD is most sensitive when calculated in all examined upper limb and lower limb muscles, followed by lower limb muscles alone. US of upper limb was found to be the least sensitive. Conclusions Muscle ultrasound is a practical and reproducible and valid tool that can be used in assessment of suspected LGMD patients.

Cortical Control of Human Motoneuron Firing During Isometric Contraction

1997 ◽  
Vol 77 (6) ◽  
pp. 3401-3405 ◽  
Author(s):  
Stephan Salenius ◽  
Karin Portin ◽  
Matti Kajola ◽  
Riitta Salmelin ◽  
Riitta Hari
Keyword(s):  
Motor Cortex ◽  
Upper Limb ◽  
Isometric Contraction ◽  
Lower Limb ◽  
Biceps Brachii ◽  
Cortical Control ◽  
Lower Limb Muscles ◽  
Cortical Rhythms ◽  
Motor Unit Firing ◽  
Limb Muscles

Salenius, Stephan, Karin Portin, Matti Kajola, Riitta Salmelin, and Riitta Hari. Cortical control of human motoneuron firing during isometric contraction. J. Neurophysiol. 77: 3401–3405, 1997. We recorded whole scalp magnetoencephalographic (MEG) signals simultaneously with the surface electromyogram from upper and lower limb muscles of six healthy right-handed adults during voluntary isometric contraction. The 15- to 33-Hz MEG signals, originating from the anterior bank of the central sulcus, i.e., the primary motor cortex, were coherent with motor unit firing in all subjects and for all muscles. The coherent cortical rhythms originated in the hand motor area for upper limb muscles (1st dorsal interosseus, extensor indicis proprius, and biceps brachii) and close to the foot area for lower limb muscles (flexor hallucis brevis). The sites of origin corresponding to different upper limb muscles did not differ significantly. The cortical signals preceded motor unit firing by 12–53 ms. The lags were shortest for the biceps brachii and increased systematically with increasing corticomuscular distance. We suggest that the motor cortex drives the spinal motoneuronal pool during sustained contractions, with the observed cortical rhythmic activity influencing the timing of efferent commands. The cortical rhythms could be related to motor binding, but the rhythmic output may also serve to optimize motor cortex output during isometric contractions.

scholarly journals Muscle perfusion of posterior trunk and lower-limb muscles at rest and during upper-limb exercise in spinal cord-injured and able-bodied individuals

Spinal Cord ◽  
2012 ◽  
Vol 50 (11) ◽  
pp. 822-826 ◽  
Author(s):  
A Zafeiridis ◽  
A V Vasiliadis ◽  
A Doumas ◽  
N Galanis ◽  
T Christoforidis ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Upper Limb ◽  
Lower Limb ◽  
Muscle Perfusion ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Posterior Trunk ◽  
Spinal Cord Injured ◽  
Limb Exercise

scholarly journals Gait Performance and Lower-Limb Muscle Strength Improved in Both Upper-Limb and Lower-Limb Isokinetic Training Programs in Individuals with Chronic Stroke

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Marie-Hélène Milot ◽  
Sylvie Nadeau ◽  
Denis Gravel ◽  
Daniel Bourbonnais
Keyword(s):  
Training Program ◽  
Upper Limb ◽  
Lower Limb ◽  
Gait Speed ◽  
Chronic Stroke ◽  
Control Group ◽  
Positive Power ◽  
Gait Performance ◽  
Lower Limb Muscles ◽  
Limb Muscles

Background. Limited improvement in gait performance has been noted after training despite a significant increase in strength of the affected lower-limb muscles after stroke. A mismatch between the training program and the requirements of gait could explain this finding. Objective. To compare the impact of a training program, matching the requirements of the muscle groups involved in the energy generation of gait, to a control intervention, on gait performance and strength. Methods. 30 individuals with chronic stroke were randomly assigned into two groups (n = 15), each training three times/week for six weeks. The experimental group trained the affected plantarflexors, hip flexors, and extensors, while the control group trained the upper-limb muscles. Baseline and posttraining values of gait speed, positive power (muscles’ concentric action during gait), and strength were retained and compared between groups. Results. After training, both groups showed a similar and significant increase in gait speed, positive power of the hip muscles, and plantarflexors strength. Conclusion. A training program targeting the lower-limb muscles involved in the energy generation of gait did not lead to a greater improvement in gait performance and strength than a training program of the upper-limb muscles. Attending the training sessions might have been a sufficient stimulus to generate gains in the control group.

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.

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