Biomaterial Database

The afferent influence on the voluntary firing range of individual motor units in man. 1979

J Hannerz, and L Grimby

The firing ranges of 50 normal anterior tibial or short toe extensor motor units in sustained isometric voluntary contraction were studied in electromyographic recordings. The afferent inflow was decreased by compression of the sciatic nerve, thereby blocking large afferents before alpha efferents. Motor units with low minimum and low maximum rates before blockade had higher minimum and maximum rates before blockade had a lower minimum but an unchanged maximum rate on blockade. The firing range recorded for both types of motor unit on blockade was also recorded for all tonically firing motor units during early reinnervation after traumatic lesion to the muscle nerve in 14 patients. It is concluded that both facilitating and inhibiting proprioceptive afferent activity is involved in the differentiation of motor unit firing ranges in sustained isometric voluntary contraction.

UI	MeSH Term	Description	Entries
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009407	Nerve Block	Interruption of NEURAL CONDUCTION in peripheral nerves or nerve trunks by the injection of a local anesthetic agent (e.g., LIDOCAINE; PHENOL; BOTULINUM TOXINS) to manage or treat pain.	Chemical Neurolysis,Chemodenervation,Nerve Blockade,Block, Nerve,Blockade, Nerve,Blockades, Nerve,Blocks, Nerve,Chemical Neurolyses,Chemodenervations,Nerve Blockades,Nerve Blocks,Neurolyses, Chemical,Neurolysis, Chemical
D010543	Peroneal Nerve	The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot.	Fibular Nerve,Fibular Nerves,Nerve, Fibular,Nerve, Peroneal,Nerves, Fibular,Nerves, Peroneal,Peroneal Nerves
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012584	Sciatic Nerve	A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.	Nerve, Sciatic,Nerves, Sciatic,Sciatic Nerves