A strain is a stretching or tearing of muscle. Symptoms are similar to sprains and include pain and stiffness, inability to use a muscle and muscle spasm. High forces may generate structural damage to the spinal bones and discs that provide the strength and framework for the back. These types of injuries may lead to pain and acute or chronic inflammation of the ligament, tendon, muscle or nerve. Eventually scarring, stenosis and degenerative changes can entrap tendons, nerves and vascular tissues. At some point the damage is irreversible and may require invasive measures to retain a partial return of function.
Task related to patient care may result in injuries to the lower back and spine due to the forces at work. The force placed on the back or spine due to the weight load of patients, on adjustable beds or chairs, and awkward positions nurses sometimes have to maintain during patient care all play a role in potential injures to ligaments, muscles and vertebrae. It is the vertebrae of the spine that provide form and support for the body. The lower back vertebrae are taller and bulkier than other vertebrae. This natural design of the human body accommodates the additional pressure from our own body weight and supports our daily actions such as; lifting, pulling, pushing and twisting.
The spine is supported by ligaments and muscles which are arranged in layers on the lower back. The first layer of muscle is covered by a thick tissue called fascia. The middle layer of muscle provides stronger support for the lower ribs, chest and lower back. The deepest layers of muscles are located along the back surface of the spinal bones, connecting to the lower back, the pelvis and the sacrum. These deep muscles work together with the muscles of the abdomen to help hold the spine steady during movement and work.
Many back problems are a result of wear and tear. Even the normal aging process contributes to a degenerative changes of the spine. Repetitive force and internal loading may result in cumulative damage and weakening of muscle layers. Normal and damaged vertebral disc are flexible and firm. The centre contains a viscous fluid and this gives the disc its ability to absorb shock and protect the spine from heavy and repeated forces. Degenerative changes in the disc, facet joints and ligaments may cause spinal segments to become painful and unstable. As a result, movement causes even more wear and tear on the spine and discs increasing the chances of ruptured disc and pinched nerves. A disc that has been weakened or suffered an unexpected shock of force may rupture. If it ruptures, the material in the nucleus can squeeze out of the disc or herniate. Depending on the direction of the rupture a disc may put pressure on a nerve root causing significant pain. Even a normal disc can rupture. Repetitive bending, twisting and lifting can place too much pressure on the disc causing the annulus to tear and the nucleus to rupture into the spinal canal.
LVNs may not be aware of the damage occurring to their spines because the nucleus of a spinal disc does not possess nociceptor or pain receptors. By the time the damage weakens the annulus of the disc and they experience pain, the damage is already done.