Hanging upside down, often called inverted traction or inversion therapy, cannot lead to a permanent increase in height. This practice provides a temporary stretching effect on the spine. The slight change in measurement people experience is related entirely to the manipulation of the spinal column, not to any change in the length of the body’s long bones.
The Temporary Change in Stature
The phenomenon that leads people to feel or measure a slight height increase is spinal decompression. Throughout the day, the constant pull of gravity and the weight of the body compress the intervertebral discs, which are the fluid-filled cushions between the vertebrae. This daily compression can cause a person to lose between a quarter to a half-inch of height from morning to evening.
Inversion temporarily reverses this effect by using gravity to gently pull the vertebrae apart. This traction creates a vacuum-like effect, allowing the discs to rehydrate and expand slightly. Studies have shown that this technique can increase stature by several millimeters following a session, but this change is short-lived. Once a person returns to an upright position, gravity immediately begins to re-compress the discs, and the temporary height gain quickly disappears.
Factors That Determine Permanent Height
Permanent height is determined by the length of the body’s long bones, such as the femurs and tibias, not by minor fluctuations in spinal disc height. The growth of these bones is controlled by specialized regions of cartilage near the ends of the bone called epiphyseal plates, or growth plates. These plates are the engines of vertical growth, where new bone tissue is formed through a process called endochondral ossification.
The activity of these growth plates is regulated by genetics, nutrition, and hormones, including growth hormone, thyroid hormone, and sex hormones. Once a person completes puberty, rising levels of sex hormones cause the cartilage in the growth plates to fully harden into solid bone, a process known as fusion. After this fusion occurs in the late teens, the long bones can no longer increase in length. No external manipulation, including inversion, can lengthen these fused bones or add to a person’s adult skeletal height.
Therapeutic Uses of Inversion
While inversion does not lead to permanent height gain, the temporary decompression it provides has applications in physical therapy and health management. Inversion tables are often used to provide temporary relief from chronic lower back pain by reducing pressure on the spinal nerves and discs. This mechanical separation of the vertebrae can alleviate pain associated with conditions like sciatica, herniated discs, and degenerative disc disease.
The U.S. Food and Drug Administration (FDA) has recognized some inversion devices as medical devices cleared for use in treating back pain, muscle tension, and related spinal conditions. By creating a non-weight-bearing environment, inversion can also help to improve circulation and promote relaxation in the muscles supporting the spine. Physical therapists often recommend inversion as a complementary treatment alongside corrective exercises and manual therapy to address spinal alignment and mobility.