Mechanism of Spasticity So what causes a muscle to become spastic? The absence of an upper motor neuron's inhibitory control on the spinal reflex. Hyp
{"Image DocumentName": "Mechanism of Spasticity", "Image ImageDescription": "Stretch Reflex. Skeletal muscle contain specialized proprioceptors called muscle spindles. Leaving the muscle spindles are Ia sensory axons. Ia input is very powerful. When the muscle spindles senses a change in length. The skeletal muscle tends to what to pull back and contract. These receptors sense a change in length for extrafusal skeletal fibers. Ia enter the spinal cord, via dorsal horn, branch repeatedly and form excitatory synapses on interneurons and alpha lower motor neurons. The Ia fibers are Thick myelinated axons. When the muscle spindles sense a change in length (such as during a pull) the Ia fibers are activated, and send excitatory stimulus to the alpha lower motor neuron. When walking, we stretch muscles upon heel strike and with the inhibitory we don\u2019t have this proble.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}