Measures of ?fastness?: force profiles of twitches and partly fused contractions in rat medial gastrocnemius and tibialis anterior muscle units

The dynamic properties of the cat soleus muscle were studied in freely walking animal preparations. The force and EMG responses of the soleus following supramaximal, ins tants of the step cycle. The sensorimotor interactions of soleus with the medial head of the gastrocnemius (a functional agonist of the soleus at the ankle) and the tibialis anterior (a functional antagonist of soleus at the ankle) were studied by measuring their force and EMG responses following the artifical stimulation of the soleus nerve. Supramaximal nerve stimulation showed distinct increases in the soleus forces during the entire swing phase and the second part (after peak forces had been reached) of the stance phase. Soleus forces could only be increased slightly in the first part of stance (from paw contact to peak force). These results suggest that force production of the soleus is virtually maximal during the early phases of stance but is submaximal for the remainder of the step cycle. Forces and EMGs of the medial gastrocnemius muscle were affected by the soleus nerve stimulation only in the latter part of the swing phase. In these cases, the force and EMG of the medial gastrocnemius were reduced significantly for the step cycle following the perturbation. The active force production of soleus during late swing causes an inhibition of medial gastrocnemius activity and force. Forces and EMGs of the tibialis anterior muscle were always affected by the soleus nerve stimulation during the swing phase of the step cycle. In these case, the force EMG of the medial gastrocnemius were reduced significantly for the step cycle following the perturbation. The active force production of soleus during late swing causes an inhibition of medial gastrocnemius activity and force. Forces and EMGs of the tibialis anterior muscle were always affected by the soleus nerve stimulation during the swing phase of the step cycle. In these instances, forces and EMGs of the tibialis anterior were significantly increased compared to step cycles preceding or following the perturbation. Part of the force enhancement is caused by the stretch of the activated tibialis anterior by the soleus, and part of the enhancement is caused by reflex activation. No effects on forces or EMGs of the tibialis anterior were observed when the soleus nerve stimulation showed its effects during the stance phase of the step cycle. The results of theis study suggest that the magnitude and the quality of ensorimotor interactions of soleus with medial gastrocnemius and tibialis anterior depend on the phase of the step cycle. The strongest interactions appear to exist during the swing phase; no observable interactions were found during stance.

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Electromyography features during physical and imagined standing up in healthy young adults, Phitsanulok, Thailand

Journal of Health Research ◽

10.1108/jhr-08-2019-0175 ◽

2020 ◽

Vol 35 (1) ◽

pp. 89-101

Author(s):

Kanokwan Srisupornkornkool ◽

Kanphajee Sornkaew ◽

Kittithat Chatkanjanakool ◽

Chayanit Ampairattana ◽

Pariyanoot Pongtasom ◽

...

Keyword(s):

Young Adults ◽

Tibialis Anterior ◽

Tibialis Anterior Muscle ◽

Rectus Femoris ◽

Biceps Femoris ◽

Voluntary Contraction ◽

Medial Gastrocnemius ◽

Content Type ◽

Standing Up ◽

Imagined Movement

PurposeTo compare the electromyography (EMG) features during physical and imagined standing up in healthy young adults.Design/methodology/approachTwenty-two participants (ages ranged from 20–29 years old) were recruited to participate in this study. Electrodes were attached to the rectus femoris, biceps femoris, tibialis anterior and the medial gastrocnemius muscles of both sides to monitor the EMG features during physical and imagined standing up. The %maximal voluntary contraction (%MVC), onset and duration were calculated.FindingsThe onset and duration of each muscle of both sides had no statistically significant differences between physical and imagined standing up (p > 0.05). The %MVC of all four muscles during physical standing up was statistically significantly higher than during imagined standing up (p < 0.05) on both sides. Moreover, the tibialis anterior muscle of both sides showed a statistically significant contraction before the other muscles (p < 0.05) during physical and imagined standing up.Originality/valueMuscles can be activated during imagined movement, and the patterns of muscle activity during physical and imagined standing up were similar. Imagined movement may be used in rehabilitation as an alternative or additional technique combined with other techniques to enhance the STS skill.

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Activity-dependent influences are greater for fibers in rat medial gastrocnemius than tibialis anterior muscle

Muscle & Nerve ◽

10.1002/mus.20369 ◽

2005 ◽

Vol 32 (4) ◽

pp. 473-482 ◽

Cited By ~ 16

Author(s):

Roland R. Roy ◽

Hui Zhong ◽

Boonclaire Siengthai ◽

V. Reggie Edgerton

Keyword(s):

Tibialis Anterior ◽

Tibialis Anterior Muscle ◽

Medial Gastrocnemius ◽

Activity Dependent

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Transversal stiffness of fibers and desmin content in leg muscles of rats under gravitational unloading of various durations

Journal of Applied Physiology ◽

10.1152/japplphysiol.00793.2010 ◽

2010 ◽

Vol 109 (6) ◽

pp. 1702-1709 ◽

Cited By ~ 29

Author(s):

I. V. Ogneva

Keyword(s):

Tibialis Anterior ◽

Structural Changes ◽

Direct Action ◽

Tibialis Anterior Muscle ◽

Muscle Fibers ◽

Medial Gastrocnemius ◽

Contractile Apparatus ◽

Gravitational Unloading ◽

Leg Muscles ◽

Transversal Stiffness

The aim of this research was the analysis of structural changes in various parts of the sarcolemma and contractile apparatus of muscle fibers by measuring their transversal stiffness by atomic force microscopy under gravitational unloading. Soleus, medial gastrocnemius, and tibialis anterior muscles of Wistar rats were the objects of the study. Gravitational unloading was carried out by antiorthostatic suspension of hindlimbs for 1, 3, 7, and 12 days. It was shown that the transversal stiffness of different parts of the contractile apparatus of soleus muscle fibers decreases during gravitational unloading in the relaxed, calcium-activated, and rigor states, the fibers of the medial gastrocnemius show no changes, whereas the transversal stiffness of tibialis anterior muscle increases. Thus the transversal stiffness of the sarcolemma in the relaxed state is reduced in all muscles, which may be due to the direct action of gravity as an external mechanical factor that can influence the tension on a membrane. The change of sarcolemma stiffness in activated fibers, which is due probably to the transfer of tension from the contractile apparatus, correlates with the dynamics of changes in the content of desmin.

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Surface EMG analysis of tibialis anterior muscle in walking with FES in stroke subjects

2010 Annual International Conference of the IEEE Engineering in Medicine and Biology ◽

10.1109/iembs.2010.5627503 ◽

2010 ◽

Cited By ~ 5

Author(s):

S K Sabut ◽

R Kumar ◽

P K Lenka ◽

M Mahadevappa

Keyword(s):

Tibialis Anterior ◽

Tibialis Anterior Muscle ◽

Surface Emg

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A High Protein Diet Does Not Improve Protein Synthesis in the Nonweight-Bearing Rat Tibialis Anterior Muscle

Journal of Nutrition ◽

10.1093/jn/126.1.266 ◽

1996 ◽

Vol 126 (1) ◽

pp. 266-272 ◽

Cited By ~ 20

Author(s):

Daniel Taillandier ◽

Charles-Yannick Guezennec ◽

Philippe Patureau-Mirand ◽

Xavier Bigard ◽

Maurice Arnal ◽

...

Keyword(s):

Protein Synthesis ◽

Tibialis Anterior ◽

Tibialis Anterior Muscle ◽

High Protein Diet ◽

High Protein ◽

Protein Diet

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Structure of the cortical cytoskeleton in fibers of postural muscles and cardiomyocytes of mice after 30-day 2-g centrifugation

Journal of Applied Physiology ◽

10.1152/japplphysiol.00812.2014 ◽

2015 ◽

Vol 118 (5) ◽

pp. 613-623 ◽

Cited By ~ 14

Author(s):

Irina V. Ogneva ◽

V. Gnyubkin ◽

N. Laroche ◽

M. V. Maximova ◽

I. M. Larina ◽

...

Keyword(s):

Skeletal Muscle ◽

Tibialis Anterior ◽

Mechanical Load ◽

Tibialis Anterior Muscle ◽

Muscle Fibers ◽

Control Group ◽

Negative Effects ◽

Transverse Stiffness ◽

G 12 ◽

Cortical Cytoskeleton

Altered external mechanical loading during spaceflights causes negative effects on muscular and cardiovascular systems. The aim of the study was estimation of the cortical cytoskeleton statement of the skeletal muscle cells and cardiomyocytes. The state of the cortical cytoskeleton in C57BL6J mice soleus, tibialis anterior muscle fibers, and left ventricle cardiomyocytes was investigated after 30-day 2- g centrifugation (“2- g” group) and within 12 h after its completion (“2- g + 12-h” group). We used atomic force microscopy for estimating cell's transverse stiffness, Western blotting for measuring protein content, and RT-PCR for estimating their expression level. The transverse stiffness significantly decreased in cardiomyocytes (by 16%) and increased in skeletal muscles fibers (by 35% for soleus and by 29% for tibialis anterior muscle fibers) in animals of the 2-g group (compared with the control group). For cardiomyocytes, we found that, in the 2- g + 12-h group, α-actinin-1 content decreased in the membranous fraction (by 27%) and increased in cytoplasmic fraction (by 28%) of proteins (compared with the levels in the 2- g group). But for skeletal muscle fibers, similar changes were noted for α-actinin-4, but not for α-actinin-1. In conclusion, we showed that the different isoforms of α-actinins dissociate from cortical cytoskeleton under increased/decreased of mechanical load.

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Losing touch: age-related changes in plantar skin sensitivity, lower limb cutaneous reflex strength, and postural stability in older adults

Journal of Neurophysiology ◽

10.1152/jn.00339.2016 ◽

2016 ◽

Vol 116 (4) ◽

pp. 1848-1858 ◽

Cited By ~ 17

Author(s):

Ryan M. Peters ◽

Monica D. McKeown ◽

Mark G. Carpenter ◽

J. Timothy Inglis

Keyword(s):

Older Adults ◽

Lower Limb ◽

Postural Stability ◽

Tibialis Anterior ◽

Tibialis Anterior Muscle ◽

Quiet Standing ◽

Detection Thresholds ◽

Cutaneous Reflex ◽

Age Related ◽

Age Related Changes

Age-related changes in the density, morphology, and physiology of plantar cutaneous receptors negatively impact the quality and quantity of balance-relevant information arising from the foot soles. Plantar perceptual sensitivity declines with age and may predict postural instability; however, alteration in lower limb cutaneous reflex strength may also explain greater instability in older adults and has yet to be investigated. We replicated the age-related decline in sensitivity by assessing monofilament and vibrotactile (30 and 250 Hz) detection thresholds near the first metatarsal head bilaterally in healthy young and older adults. We additionally applied continuous 30- and 250-Hz vibration to drive mechanically evoked reflex responses in the tibialis anterior muscle, measured via surface electromyography. To investigate potential relationships between plantar sensitivity, cutaneous reflex strength, and postural stability, we performed posturography in subjects during quiet standing without vision. Anteroposterior and mediolateral postural stability decreased with age, and increases in postural sway amplitude and frequency were significantly correlated with increases in plantar detection thresholds. With 30-Hz vibration, cutaneous reflexes were observed in 95% of young adults but in only 53% of older adults, and reflex gain, coherence, and cumulant density at 30 Hz were lower in older adults. Reflexes were not observed with 250-Hz vibration, suggesting this high-frequency cutaneous input is filtered out by motoneurons innervating tibialis anterior. Our findings have important implications for assessing the risk of balance impairment in older adults.

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