The muscles of the back can be divided into three groups – superficial, intermediate and deep: Superficial – associated with movements of the shoulder. Intermediate – associated with movements of the thoracic cage. Deep – associated with movements of the vertebral column. The deep muscles develop embryologically in the back, and are thus described as intrinsic muscles. The superficial and intermediate muscles do not develop in the back, and are classified as extrinsic muscles. This article is about the anatomy of the superficial back muscles – their attachments, innervations and functions. The superficial back muscles are situated underneath the skin and superficial fascia. They originate from the vertebral column and attach to the bones of the shoulder – the clavicle, scapula and humerus. All these muscles are therefore associated with movements of the upper limb. The muscles in this group are the trapezius, latissimus dorsi, levator scapulae and the rhomboids. The trapezius
What is a P.I.V.D or prolapsed disc ? The term PIVD /prolapsed intervertebral disc means the protrusion or extrusion of the nucleus pulposus through a rent in the annulus fibrosus . It has a four stages- Bulging - At this early stage, the disc is stretched and doesn't completely return to its normal shape when pressure is relieved. It retains a slight bulge at one side of the disc. Some of the inner disc fibres could be torn and the soft jelly ( nucleus pulposus ) is spiling outwards into the disc fibres but not out of the disc. Protrusion - At this stage, the bulge is very prominent and the soft jelly centre has spilled out to the inner edge of the outer fibres, barely held in by the remaining disc fibres. Extrusion - In the case of a herniated spinal disc, the soft jelly has completely spilled out of the disc and now protruding out of the disc fibres. Sequestration - Here some of the jelly material is breaking off away from the disc into the surrounding area. prolaps