The length-tension relationship is a fundamental property of muscle. In its classic form, which is used in muscle models incorporated into studies of motor control, the length-tension relationship is measured during maximal activation via tetanic electrical stimulation in whole muscles or during high intracellular calcium levels in single muscle fibers. In this study, we measured the length-ten...

Introduction: Muscles can adapt to altered length change by increasing or decreasing serial sarcomere number [1]. The functional result of this adaptation is for the muscle to work on or around optimal sarcomere length. If this finding applies to muscles after tendon transfer surgery, this would be desirable, as intraoperative measurements reveal that transferred muscles may be overstretched to...

OBJECTIVE To characterize the isometric contractility of Bufo gastrocnemius ex vivo in light of the rest tension. METHODS Bufo gastrocnemius treated with SOD inhibitor and ascorbate was stimulated electrically (12 V DC, 2 ms duration with a 2 s interval) to record the tension within 10 min. Weighted fitting to the relaxation curve of the tension below 90% of the peak tension with a mono-expon...

• It has often been reported that increased arterial blood pressure leads to the production of cardiac arrhythmias. 1-0 Similarly, increased pacemaker activity occurs when various cardiac tissues are stretched 7> 8 and recently Keatinge 9 also showed that quiescent isolated rabbit atrium or ventricle will start to beat when the pressure inside is raised. The present experiments were designed to...

Many factors influence successful outcomes following transfemoral amputation. One factor is surgical technique. In this study, the influence of limb alignment and surgical technique on a muscle's capacity to generate force was examined using musculoskeletal modeling. Non-amputee and transfemoral amputee models were analyzed while hip adduction, femur length, and reattached muscle wrap position,...

A contractile property of phenylephrine (PE), alpha 1 agonist, on rat anococcygeus muscle was compared with that on rat aorta by simultaneously measuring changes in intracellular Ca2+ ([Ca2+]i) level and muscle tension. (1) PE (0.1-30 microM) and high K+ induced a sustained increases in [Ca2+]i level and muscle tension of both the muscles. (2) An application of verapamil (10 microM) and EGTA (4...

Undulatory animal locomotion arises from three closely related propagating waves that sweep rostrocaudally along the body: activation of segmental muscles by motoneurons (MNs), strain of the body wall, and muscle tension induced by activation and strain. Neuromechanical models that predict the relative propagation speeds of neural/muscle activation, muscle tension and body curvature can reveal ...

BACKGROUND Central and peripheral mechanisms may be involved in migraine and tension-type headache pathogenesis, however the role of muscle disorders in their pathophysiological mechanisms remains unclear. OBJECTIVES To assess the association between the presence of migraine or tension-type headache and changes in longus colli muscle dimensions and sternocleidomastoid muscle activity. METHO...

A prospective double blinded controlled study was done to assess the relation between flaring of ala nasi and abductor spasms in abductor spasmodic dysphonia. All the 24 cases of clinically and stroboscopically proven cases of abductor spasmodic dysphonia were found to have visible and easily detectable flaring of ala nasi during the abductor spasm. Among the control group of 24 dysphonia patie...

A 16-year-old male patient who presented with muscle stiffness and dysphonia is described. Electromyography revealed continuous motor activity that was unaffected by peripheral nerve block or general anaesthesia, but was abolished by curare. The patient had a marked improvement after using phenytoin. The follow-up 11-years later corroborates with the proposed benignity of this syndrome, in spit...