Hypopressive exercise

Hypopressive exercise (also known as hypopressive gymnastics, hypopressive technique, hypopressive method, hypopressive abdominal exercises, hypopressive abdominal technique) refers to a type of physical therapy developed in the 1980s by Marcel Caufriez, studying urogynecological postpartum recovery. The exercises were developed after Caufriez was performing a vaginal examination on a patient with uterine prolapse. He observed reduction of the prolapse during diaphragmatic aspiration. Since the development of the exercises, there have been a handful of initial studies which suggest the exercises may be of benefit in pelvic organ prolapse and incontinence. The exercises are also claimed to be of benefit in sports and prevention.

Etymology
Hypo- comes from the Greek word ὑπο meaning "under". "Pressive" has the French origin pressif meaning "urgent", or alternately, marked by pressure or oppressiveness. Hence, hypopressive could be defined as "inducing lowered pressure."

Technique
The essential features of hypopressive exercise involve exhalation with expansion of the ribcage, which is paradoxical to normal ribcage movement during exhalation. The resultant negative pressure in the thoracic cavity thereby elevates the diaphragm. Apnea is then maintained after this exhalation (i.e. not breathing after exhalation). In response to the reduced adbominopelvic pressure, there is involuntary contraction of the pelvic floor and abdominal wall. This posture gives the exercise its recognizable appearance of expanded ribcage and contracted abdomen, which is then combined into a variety of postures and motions.

Theory
While voluntary contraction involvestype II muscle (fast twitch) fibers, the hypopressive exercises are claimed to stimulate type I (slow twitch) fibers. Since the pelvic floor is composed of mainly involuntary fibers, traditional exercise may reduce the basal tonicity of the pelvic floor muscles.

The three criteria described by Caufriez that define a hypopressive exercise are:


 * Decreased pressure within the thoracic, abdominal, and perineal cavities
 * Reflexive electromyographic activity in the core muscles (abdominal wall and pelvic floor)
 * Neurovegetative reactivity measured by an increase in noradrenaline

Hypothesized explanations for these changes include splenic contraction reflex or changes in erythropoietin.

Claimed benefits
The list of claimed benefits of these exercises is extensive, however many of these appear to be based on weak or theoretical evidence. There are only a handful of formal scientific studies on the topic, which have been small cohort, initial studies. Some of the purported benefits of hypopressive exercise are not discussed in the available scientific literature. To firmly assess these claims, large randomized control trials are required.

A few of the claimed benefits are comparable to the proven benefits of pelvic floor muscle exercises (Kegel exercises), and it is known that the pelvic floor is recruited during hypopressive exercise.

Proponents claim benefits include reduced waist size and flattening the abdominal wall, increased abdominal wall and pelvic floor muscle tone, decreased pelvic congestion, improved support of the pelvic organs, both prevention and treatment of urinary incontinence and prolapse, prevention of hernias, improved sexual sensation and ability to orgasm, posture normalization, decreased back pain, promoted blood flow to legs, sympathetic stimulation, enhanced athletic capability and may help in the treatment of asthma.

Evidence base
Esparza 2007 studied 100 women with stress urinary incontinence and hypotonic pelvic floor muscles. The study reported an increase in pelvic floor muscle tone and 6% decrease in waist circumference after 6 months of hypopressive training.

Fernandez 2007 studied the effects of hypopressive training in older adults with urinary incontinence. After 6 months hypopressive exercises, they reported an increase in base tone by 23.5%. In 85.7% of cases there were decreased or elimination of symptoms.

Caufriez 2007 reported effects of 10 weeks hypopressive training on posture. The results included reduced lumbar lordosis and cervical lordosis, decreased kyphosis. Subjective improvements were reported by the subjects regarding postural comfort.

A 2010 study of 126 women investigated the effect of abdominal exercises compared to hypopressive exercises for 14 weeks. Hypopressive group had an average of 3.5 cm waist circumference and decreased scoring on a urinary incontinence questionnaire. Incontinence was eliminated in some of the subjects.

Stüpp 2011 compared abdominal hypopressive technique with pelvic floor muscle exercises, looking at the effect of transverse abdominis contraction in 34 subjects (physical therapists, none of which had given birth before, and more than half of which were physically active). They found that hypopressives produced less transverse abdominis contraction than pelvic floor muscle exercises, but when the two exercises were combined there was better contraction than pelvic floor muscle exercise alone.

Caufriez 2011 studied the effect of hypopressive gymnastics in three children with idiopathic scoliosis. They measured deformation of the ribcage (gibbosity) and curvature of the spine before and after the training. They reported vertebral stabilisation and stabilisation of gibbosity. They concluded that these changes might improve respiratory function.

Bernardes 2012 studied the cross sectional area of levator ani in 58 women with stage II pelvic organ prolapse. The reason for measuring the size of levator ani was that decreased cross-sectional area of this muscle is thought to be related to pelvic floor dysfunction. The patients were divided into 3 groups: normal pelvic floor exercises, hypopressive exercises and a control group. They reported similar increases in the cross sectional area of levator ani produced with both pelvic floor exercises and hypopressive exercises.

Resende 2012 (the same research group as above) again compared pelvic floor muscle training and hypopressive exercises in patients with pelvic organ prolapse. They found that both types of exercise improved pelvic floor function, but adding hypopressives to pelvic floor exercises did not yield further improvement compared to pelvic floor exercise alone.