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.
The short answer is-no pun intended-muscles shorten when they contract. This begs the question of how muscles shorten and, thus, contract. To answer this question, we must first examine the components of the sarcomere, which is the fundamental functional unit of striated muscle-that is, skeletal and cardiac muscle.To say that the sarcomere is the functional unit means that all the components needed for contraction are contained within each sarcomere.hile each sarcomere is small, several sarcomeres added together span the length of the muscle fiber. Each sarcomere consists of thick and thin bundles of proteins referred to as myofilaments. If we magnify a portion of the myofilaments, we can identify the molecules that compose them.