Inversion therapy

Foldable inversion table, extended and set up for use.

Inversion table in action.

Inversion therapy involves hanging upside down or at an inverted angle with the intention of therapeutic benefits. However, it is rarely regarded as a serious treatment for back pain.

Claims

Traction and stretching

When the body's weight is suspended from the lower body – rather than borne on the hands as in handstands or headstands or hanging from a bar with arms at sides, which are also forms of inversion – the pull of gravity may decompress the joints of the body below the anchor. Hanging by the feet, as with gravity boots or inversion tables, causes each joint in the body to be loaded in an equal and opposite manner to standing in an identical position of joint alignment. Inversion therapy of this sort is often commercially advertised as a relief for back pain.

Proponents claim that inversion therapy is particularly beneficial for the spine in that it relieves pressure on the discs and nerve roots; this in turn allows discs to recover lost moisture and to return to their original shape, decreasing the pressure they can exert on nerves. Skeptics note that pressure is also relieved when lying down in bed. Proponents counter that while gravity-related pressure is removed, the pressure of tight muscles is not, and that traction is needed to allow the possible space between spinal discs to be realized.

Posture

Proponents advocate that traction can be a tool to restore proper alignment to the spine, which may assist in maintaining proper posture when later righted. As misalignment of the hips and spine can itself be a source of inflammation and pain, this is another argument for traction as a back therapy.

Flexibility

Inversion devices are promoted as a tool to be used in gaining flexibility. Static-active stretching methods impossible to perform while standing can be performed upside down for the spinal flexors, side flexors and extensors, and situps are a closed-chain exercise for the hip flexors (a static-active stretch for the hip extensors) compared to the upright exercise, leg raises, which are open-chain movements. Due to increased spacing in the joint which can occur in response to traction, the muscles crossing that joint are pre-stretched, and as such, experience a greater lengthening compared to the equivalent joint angle while under no traction (lying down) or while being compressed (standing).

Blood flow

Claims are made that inversion stimulates circulation differences due to gravity acting on the circulatory system in an opposite manner, opposing what it would normally assist, and assisting what it would normally oppose compared to standing upright. This pooling of blood and greater circulation is thought by some to increase oxygen flow to those tissues, primarily in the brain or roots of the hair,

Efficacy

Several research studies into inversion therapy have taken place, focusing on its efficacy with regard to reduction of back pain, avoidance of surgery and a decrease in employees’ lost working hours.

The Kane study demonstrated that gravity-facilitated traction produces significant intervertebral separation in the lumbar spine, concluding that gravity-facilitated traction may be an effective modality in the relief of low back pain.

The Nosse study found that EMG activity (an indicator of muscle pain) declined by 35 per cent within the first 10 seconds of inversion. The study also found that inversion increases spinal length, concluding that there was a correlation between a reduction in EMG activity and an increase in spinal length.

The Dimberg/Volvo study evaluated 116 Volvo employees in a randomized controlled trial that lasted for 12 months. Three training groups were studied, and after 12 months, the researchers demonstrated a 33 per cent decrease in sick days from back pain. The average sick days lost to back pain fell by eight days per individual in the treated group. The study concluded that inversion is an efficient and cost-effective way to improve employee health and possibly reduce sick day costs to an employer.

The Sheffield study evaluated 175 patients whose back pain left them unable to work. Following eight inversion treatments, 155 patients were able to return to their jobs full time.

Health risks

People who have heart disease, high blood pressure, eye diseases (such as glaucoma), or are pregnant are at higher risk for the dangers related to inversion therapy and should consult their doctors about it first. Such people would have to progress very slowly, starting at very light levels of inversion. The first time anyone tries inversion therapy with gravity, they should be sure to have someone standing by, in case assistance is required to get out of the apparatus, or if health problems are experienced.

See also

• Gravity boots