Common Causes of Pinched Nerves. The most common forms of nerve compression are in the spinal joints where either a disc bulge or a bony arthritic spur can irritate and compress the nerve. Compressions can also occur as the nerve passes through or around muscles. Your physiotherapist will know where to look.
Muscle fibers are in turn composed of myofibrils. The myofibrils are composed of actin and myosin filaments, repeated in units called sarcomeres, the basic functional units of the muscle fiber.The sarcomere is responsible for the striated appearance of skeletal muscle, and forms the basic machinery necessary for muscle contraction.n addition to the actin and myosin components that constitute the sarcomere, skeletal muscle fibers also contain two other important regulatory proteins, troponin and tropomyosin, that are necessary for muscle contraction to occur.
Motor unit : consists of the motor nerve and all the muscle fibers it innervates. The motor unit (not the individual muscle cell) is the functional contractile unit. The nerve branches are dispersed throughout the muscle and not clustered in one area. Fine control : a motor neuron will only branch about 20X; allows for fine control and movement. Strength control : motor neuron will branch about 1000X; for strength and large movement .