scholarly journals MECHANICS OF VOLUNTARY AND INVOLUNTARY MUSCLE ACTIONS

1989 ◽  
Vol 21 (Supplement) ◽  
pp. S68 ◽  
Author(s):  
B. Hather ◽  
M. Duvoisin ◽  
R. Harris ◽  
P. Buchanan ◽  
G. Dudley
Keyword(s):  
Involuntary Muscle ◽  
Muscle Actions

MECHANICS OF VOLUNTARY AND INVOLUNTARY MUSCLE ACTIONS

1980 ◽  
Vol 21 (Supplement) ◽  
pp. S68
Author(s):  
B. Hather ◽  
M. Duvoisin ◽  
R. Harris ◽  
P. Buchanan ◽  
G. Dudley
Keyword(s):  
Involuntary Muscle ◽  
Muscle Actions

Influence of Velocity on Agonist and Antagonist Activation in Concentric Dorsiflexion Muscle Actions

1996 ◽  
Vol 21 (5) ◽  
pp. 403-416 ◽  
Author(s):  
David G. Behm ◽  
Digby G. Sale
Keyword(s):  
Gender Difference ◽  
Movement Time ◽  
Lateral Gastrocnemius ◽  
Velocity Relation ◽  
Relative Activation ◽  
Agonist And Antagonist ◽  
Integrated Emg ◽  
Body Mass Ratio ◽  
Activation Ratio ◽  
Muscle Actions

Five women and 5 men performed maximal isometric and concentric dorsiflexion actions on an isokinetic dynamometer. The concentric actions were done at 10 preset velocities ranging from 0.26 to 5.23 rad∙s−1. Electromyographic (EMG) recordings were made from one agonist (tibialis anterior [TA]) and two antagonists (saleus [S], lateral gastrocnemius [LG]). The men produced greater absolute torque than the women, but there was no gender difference in the torque/body mass ratio. The shape of the torque-velocity relation was similar in men and women and approximated, but did not match, that obtained in animal preparations or in human studies using electrical stimulation. Agonist TA activation (integrated EMG/movement time) decreased with increasing velocity over the same range of velocities as torque. Antagonist S, but not LG, activation also decreased. The S/TA activation ratio was greater in men than women. In men the S/TA ratio tended to be greater than the LG/TA ratio, whereas the converse was true for women. These data indicate that velocity influences the relative activation of two antagonists in maximal dorsiflexion muscle actions, and that there is an apparent gender difference in the relative activation of two antagonists. Key words: torque-velocity relation, coactivation, electromyography

scholarly journals Energy cost and muscular activity required for propulsion during walking

2003 ◽  
Vol 94 (5) ◽  
pp. 1766-1772 ◽  
Author(s):  
Jinger S. Gottschall ◽  
Rodger Kram
Keyword(s):  
Body Weight ◽  
Muscular Activity ◽  
Metabolic Cost ◽  
Medial Gastrocnemius ◽  
Emg Activity ◽  
Horizontal Force ◽  
Normal Walking ◽  
The Mean ◽  
The Cost ◽  
Muscle Actions

We reasoned that with an optimal aiding horizontal force, the reduction in metabolic rate would reflect the cost of generating propulsive forces during normal walking. Furthermore, the reductions in ankle extensor electromyographic (EMG) activity would indicate the propulsive muscle actions. We applied horizontal forces at the waist, ranging from 15% body weight aiding to 15% body weight impeding, while subjects walked at 1.25 m/s. With an aiding horizontal force of 10% body weight, 1) the net metabolic cost of walking decreased to a minimum of 53% of normal walking, 2) the mean EMG of the medial gastrocnemius (MG) during the propulsive phase decreased to 59% of the normal walking magnitude, and yet 3) the mean EMG of the soleus (Sol) did not decrease significantly. Our data indicate that generating horizontal propulsive forces constitutes nearly half of the metabolic cost of normal walking. Additionally, it appears that the MG plays an important role in forward propulsion, whereas the Sol does not.

Clofibrate and vascular smooth muscle: Actions on rabbit aorta preparations

1981 ◽  
Vol 72 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Alan S. Fairhurst ◽  
Gerald Kent ◽  
Ralph E. Purdy
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Rabbit Aorta ◽  
Muscle Actions

The Use of Multimodal Feedback in Retraining Complex Technical Skills of Piano Performance

2005 ◽  
Vol 20 (2) ◽  
pp. 82-88
Author(s):  
Kathleen Riley ◽  
Edgar E Coons ◽  
David Marcarian
Keyword(s):  
Video Recording ◽  
Physical Injury ◽  
Multimodal Approach ◽  
Piano Performance ◽  
Improve Technique ◽  
Multimodal Feedback ◽  
Piano Students ◽  
Muscle Balance ◽  
Accuracy Increase ◽  
Muscle Actions

Piano students working to improve technique often practice the same passage over and over to achieve accuracy, increase speed, or perfect interpretive nuance. However, without proper skeletal alignment of hands, arms, and shoulders and balance between the muscles involved, such repetition may lead to difficulties with, rather than mastery of, technique and stylistic interpretation and even physical injury. A variety of technologies have been developed to monitor skeletal alignment and muscle balance that serve to help students and teachers make needed corrections during performance by providing immediate biofeedback. This paper describes and illustrates a multimodal use of these biofeedback technologies and the powerful advantages of such a multimodal approach in making the student and teacher not only aware of improper alignments and balances in real time (or for later review) but also aware of approaches to correct them and improve musical outcome. The modalities consist of hearing playback through a Disklavier piano; simultaneous visual feedback displayed as a piano roll screen of what was played; video recording synchronized with the Disklavier and piano roll feedback; motion analysis of the arms, hands, and fingers; and electromyographic recordings of the muscle actions involved.

Opioid-Induced Muscle Activity: Implications for Managing Chronic Pain

1995 ◽  
Vol 29 (11) ◽  
pp. 1118-1121 ◽  
Author(s):  
Robert K Sylvester ◽  
Ralph Levitt ◽  
Preston D Steen
Keyword(s):  
Breakthrough Pain ◽  
Oral Morphine ◽  
Opioid Therapy ◽  
Chronic Opioid Therapy ◽  
Transdermal Fentanyl ◽  
Management Options ◽  
Morphine Infusion ◽  
Involuntary Muscle ◽  
Metastatic Lung ◽  
Morphine Solution

Objective: To increase awareness of opioid-induced involuntary muscle hyperactivity and to present management options. Case Summary: A ventilator-dependent 71-year-old man presented with pain caused by metastatic lung cancer. Transdermal fentanyl therapy was titrated to 200 μg/h. Two days later a continuous morphine infusion was initiated because of frequent administration of oral morphine solution for breakthrough pain. The patient became progressively less responsive and began exhibiting involuntary muscle hyperactivity thought to represent breakthrough pain. Despite the inability to assess pain control effectively in this unresponsive patient, the morphine infusion rate was increased from 22 to 717 mg/h within 7 days. No change in muscle hyperactivity was observed. Discussion: Over the last decade involuntary muscle hyperactivity has been documented as an adverse effect of chronic opioid therapy. The literature describing the incidence of this toxicity, possible risk factors for its development, and recommendations for its management are discussed. Conclusions: The occurrence of muscle hyperactivity in an unresponsive patient receiving chronic opioid therapy may represent opioid toxicity. Recommendations for managing opioid-induced muscle hyperactivity include reduction of the opioid dosage and/or administration of clonazepam therapy.

scholarly journals Development of Postural Muscles and Their Innervation

2005 ◽  
Vol 12 (2-3) ◽  
pp. 141-151 ◽  
Author(s):  
J. IJkema-Paassen ◽  
A. Gramsbergen
Keyword(s):  
Motor Performance ◽  
Muscle Fibers ◽  
Animal Experiments ◽  
Great Resistance ◽  
Fiber Properties ◽  
Flexor Muscles ◽  
Dendrite Bundles ◽  
Arm Muscles ◽  
Muscle Actions ◽  
Postural Muscles

Control of posture is a prerequisite for efficient motor performance. Posture depends on muscles capable of enduring contractions, whereas movements often require quick, forceful muscle actions. To serve these different goals, muscles contain fibers that meet these different tasks. Muscles with strong postural functions mainly consist of slow muscle fibers with a great resistance against fatigue. Flexor muscles in the leg and arm muscles are mainly composed of fast muscle fibers producing relatively large forces that are rapidly fatigable. Development of the neuromuscular system continues after birth. We discuss in the human baby and in animal experiments changes in muscle fiber properties, regression from polyneural into mononeural innervation, and developmental changes in the motoneurons of postural muscles during that period. The regression of poly-neural innervation in postural muscles and the development of dendrite bundles of their motoneurons seem to be linked to the transition from the immature into the adult-like patterns of moving and postural control.

Sign in / Sign up

Export Citation Format

Share Document