Lumbar traction is the process of applying a stretching force to the lumbar vertebrae through body weight, weights, and/or pulleys to distract individual joints of the lumbar spine. The word traction is a derivative of the Latin word "tractico", which means "a process of drawing or pulling, and various forms of spinal traction have been described, since the time of Hippocrates, for the relief of pain.
The lumbar spine is made up of five individual vertebrae which are numbered L1 to L5 and together they create the concave lumbar curvature in the lower back. Found along the body’s midline in the lumbar (lower back) region, the lumbar vertebrae make up the region of the spine inferior to the thoracic vertebrae in the thorax and superior to the sacrum and coccyx in the pelvis.These vertebrae carry all of the upper body’s weight while providing flexibility and movement to the trunk region. They also protect the delicate spinal cord and nerves within their vertebral canal.
Connecting each vertebra to its neighbouring vertebra is an intervertebral disk made of tough fibrocartilage with a jelly-like centre. The outer layer of the intervertebral disk, the annulus fibrosis, holds the vertebrae together and provides strength and flexibility to the back during movement. The jelly-like nucleus pulposus acts as a shock absorber to resist the strain and pressure exerted on the lower back.
The lumbar vertebrae are the some of the largest and heaviest vertebrae in the spine, second in size only to the sacrum. A cylinder of bone known as the vertebral body makes up the majority of the lumbar vertebrae’s mass and bears most of the body’s weight. Posteriorly the body is connected to a thin ring of bone known as the arch. The arch surrounds the hollow vertebral foramen and connects the body to the bony processes on the posterior of the vertebra. The vertebral foramen is a large, triangular opening in the centre of the vertebra that provides space for the spinal cord, cauda equina, and meninges as they pass through the lower back.
Extending from the vertebral arch are several bony processes that are involved in muscle attachment and movement of the lower back. The spinous process extends from the posterior end of the arch as a thin rectangle of bone. It serves as a connection point for the muscles of the back and pelvis, such as the psoas major and interspinales. On the left and right lateral sides of each vertebra are the short, triangular transverse processes. The transverse processes form important connection points for many muscles, including the rotatores and multifidus muscles that extend and rotate the trunk.
Unlike the cervical vertebrae in the neck, the lumbar vertebrae lack the transverse foramina in the transverse processes, and also lack facets to either side of the body. The fifth lumbar vertebra is distinct from the L1-4 vertebrae in being much larger on its front side than in the back. Its spinous process, on the other hand, is smaller than in the other lumbar vertebrae with a wide, four-sided shape that comes to a rough edge and a thick notch.
Types of Lumbar Traction
Several types of lumbar traction are described in literature but the most used include:
- Continuous Traction - Continuous or bed traction uses low weights for extended periods of time (up to several hours at a time). This long duration requires that only small amounts of weight be used. It is generally believed that this type of traction is ineffective in actually separating the spinal structures. In other words, the patient cannot tolerate weights great enough to cause separation of the vertebrae for that length of time.
- Sustained Traction - This type of traction involves heavier weights applied steadily for short periods of time (for periods from a few minutes up to 1 hr). Sustained traction is sometimes referred to as static traction.
- Intermittent Mechanical Traction - Intermittent traction is similar to sustained traction in intensity and duration but utilises a mechanical unit to alternately apply and release the traction force at preset intervals
- >Manual Traction - Manual traction is applied as the clinician's hands and /or a belt are used to pull on the patient's legs. It is usually applied for a few seconds duration or can be applied as a sudden, quick thrust.
- Autotraction - Autotraction utilises a specially designed table that is divided into two sections that can be individually tilted and rotated. The patient provides the traction force by pulling with the arms and/or pushing with the feet. Investigations of autotraction have reported favourable clinical results but no change in size or location of lumbar disc herniation
- Positional Traction - This form of traction is applied by placing the patient in various positions using pillows, blocks, or sandbags to effect a longitudinal pull on the spinal structures. It usually incorporates lateral bending and is only affected to one side of the spinal segment
- Gravity lumbar traction - involves using a chest harness to secure the patient as the treatment table is tilted to a vertical position, thereby using the weight of the lower half of the body to provide a traction force.