Search results
Results from the WOW.Com Content Network
Antagonist muscles are simply the muscles that produce an opposing joint torque to the agonist muscles. [9] This torque can aid in controlling a motion. The opposing torque can slow movement down - especially in the case of a ballistic movement. For example, during a very rapid (ballistic) discrete movement of the elbow, such as throwing a dart ...
If opposing muscles were to contract at the same time, a muscle tear can occur. This may occur during physical activities such as running, during which opposing muscles engage and disengage sequentially to produce coordinated movement. Reciprocal inhibition facilitates ease of movement and is a safeguard against injury.
The result of this motor nerve activity is contraction of the quadriceps muscle, leading to extension of the lower leg at the knee (i.e. the lower leg kicks forward). Ultimately, an improper patellar reflex may indicate an injury of the central nervous system .
At the same time, signals travel up the spinal cord and cause contraction of the contralateral muscles of the hip and abdomen to shift the body’s center of gravity over the extended leg. To a large extent, the coordination of all these muscles and maintenance of equilibrium is mediated by the cerebellum and cerebral cortex. [5]
A muscle synergy is composed of agonist and synergistic muscles. An agonist muscle is a muscle that contracts individually, and it can cause a cascade of motion in neighboring muscles. Synergistic muscles aid the agonist muscles in motor control tasks, but they act against excess motion that the agonists may create.
Knee pain is thought to be primarily associated with specific quadriceps muscle weakness or fatigue, especially in the vastus medialis obliquus (VMO).It is known that fatigue can be caused by many different mechanisms, ranging from the accumulation of metabolites within muscle fibers to the generation of an inadequate motor command in the motor cortex. [4]
The patellar reflex, also called the knee reflex or knee-jerk, is a stretch reflex which tests the L2, L3, and L4 segments of the spinal cord. Many animals, most significantly humans, have been seen to have the patellar reflex, including dogs, cats, horses, and other mammalian species.
Reciprocal innervation describes skeletal muscles as existing in antagonistic pairs, with contraction of one muscle producing forces opposite to those generated by contraction of the other. For example, in the human arm, the triceps acts to extend the lower arm outward while the biceps acts to flex the lower arm inward. To reach optimum ...