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Full-Text Articles in Life Sciences
Maximal Motor Unit Discharge Rates Of The Medial And Lateral Gastrocnemeii Of Young Males, Mitchell T. Graham
Maximal Motor Unit Discharge Rates Of The Medial And Lateral Gastrocnemeii Of Young Males, Mitchell T. Graham
Electronic Thesis and Dissertation Repository
The triceps surae is composed of the mono-articular soleus and the bi-articular gastrocnemeii. Mean maximal motor unit discharge rates (MUDRs) reported for the soleus (~16Hz) are lower than other limb muscles tested (Dalton et al., 2009). Because of differences in fibre-type and functional anatomy it is important to determine maximal MUDRs in the two heads of gastrocnemeii, as compared with the soleus, to fully understand the interplay of these three muscles for plantar flexion. The purpose of the study was to record maximal MUDRs of the medial (MG) and lateral gastrocnemeii (LG) in 9 recreationally active, young men (age 24.2 …
Comprehensive Analysis Of Abdominal Tendon Length:Muscle Length Ratios In Human And Rat Specimens, Alexander J. Stephen
Comprehensive Analysis Of Abdominal Tendon Length:Muscle Length Ratios In Human And Rat Specimens, Alexander J. Stephen
Electronic Thesis and Dissertation Repository
Introduction: This study measured and described the tendon to muscle length ratios (TMRs) of the external oblique (EO), internal oblique (IO), rectus abdominus (RA), and transverse abdominus (TrA) muscles in humans and rats. Methods: The abdominal muscles of human and rat specimens were dissected and the length of the muscle fibers from their posterior attachments to the lumbodorsal fascia or the rib cage, and the lengths of their tendons, were measured. The tendon length was divided by muscle fiber length to calculate the TMR. Results: The TMRs for the human EO, IO, and TrA muscles were significantly larger than the …
Effect Of Age On The Hemodynamic And Sympathetic Responses At The Onset Of Isometric Handgrip Exercise., Sophie Lalande, Carolyn P Sawicki, Jacquie R Baker, Kevin Shoemaker
Effect Of Age On The Hemodynamic And Sympathetic Responses At The Onset Of Isometric Handgrip Exercise., Sophie Lalande, Carolyn P Sawicki, Jacquie R Baker, Kevin Shoemaker
Kinesiology Publications
Cardiac and peripheral vasomotor factors contribute to the rapid pressor response at the onset of isometric handgrip exercise. We tested the hypothesis that age enhances the sympathetic and vasoconstrictor response at the onset of isometric handgrip exercise so that the pressor response is maintained, despite a diminished cardiac function. Twelve young and twelve older (24 ± 3 and 63 ± 8 yr) individuals performed 20-s isometric handgrip exercise at 30, 40, or 50% of maximal voluntary contraction force. Muscle sympathetic nerve activity (MSNA) was measured using microneurography. Mean arterial pressure (MAP) and cardiac output (Q) were assessed continuously by finger …