Search results
Results from the WOW.Com Content Network
The tibialis anterior muscle is a muscle of the anterior compartment of the lower leg. It originates from the upper portion of the tibia; it inserts into the medial cuneiform and first metatarsal bones of the foot. It acts to dorsiflex and invert the foot. This muscle is mostly located near the shin. It is situated on the lateral side of the ...
Decreased tibialis anterior activity allows the gastrocnemius to more completely plantar flex, or point the toe. This allows the foot to slide over the obstacle. Increased vastus lateralis activity produces a co-contraction of the hamstrings and quadriceps, which provides increased knee stability in case of a stumble or fall.
Lower leg muscles acting on the ankle are the dorsiflexors (tibialis anterior) and plantarflexors (gastrocnemius and soleus). The gastrocnemius/soleus is active in the last part of swing phase to prepare for foot strike and remain active through stance until just before toe-off in order to propel the body forward.
The action potential in a normal skeletal muscle cell is similar to the action potential in neurons. [61] Action potentials result from the depolarization of the cell membrane (the sarcolemma ), which opens voltage-sensitive sodium channels; these become inactivated and the membrane is repolarized through the outward current of potassium ions.
(b) A functional electrical stimulation system injects electrical current into the cell. (c) The intact but dormant axon receives the stimulus and propagates an action potential to (d) the neuromuscular junction. (e) The corresponding muscle fibers contract and generate (f) muscle force. (g) A train of negative pulses is produced.
Motor unit. In biology, a motor unit is made up of a motor neuron and all of the skeletal muscle fibers innervated by the neuron's axon terminals, including the neuromuscular junctions between the neuron and the fibres. [1] Groups of motor units often work together as a motor pool to coordinate the contractions of a single muscle.
45163. Anatomical terminology. [ edit on Wikidata] The anterior compartment of the leg is a fascial compartment of the lower leg. It contains muscles that produce dorsiflexion and participate in inversion and eversion of the foot, as well as vascular and nervous elements, including the anterior tibial artery and veins and the deep fibular nerve.
An integrating center, the point at which the neurons that compose the gray matter of the spinal cord or brainstem synapse. Efferent nerve fibers carry motor nerve signals from the anterior horn to the muscles. Effector muscle innervated by the efferent nerve fiber carries out the response. A reflex arc, then, is the pathway followed by nerves ...