About 25 percent of women in the United States suffer from pelvic floor disorders (PFD), which include pelvic organ prolapse (POP), urinary incontinence (UI), and fecal incontinence (FI). Pelvic floor disorders occur when the pelvic muscles are no longer able to support the abdominal organs. Risk factors for pelvic floor disorders include childbirth, aging, being of Caucasian race, and intra-abdominal pressure (IAP).
Intra-abdominal pressure, or IAP, is the pressure inside the abdominal cavity, which is affected by body mass index (BMI) and posture. IAP tends to be higher in obese individuals and people with poor posture. It also varies during daily activities. IAP is higher while walking, exercising, or lifting weights. High IAP increases the risk for pelvic floor disorders. Therefore, women should maintain low IAP levels.
It is unclear how intra-abdominal pressure predisposes women for new or recurrent pelvic floor disorders. Nevertheless, the American Urogynecologic Society recommends that women avoid heavy lifting and repetitive strenuous exercises in order to prevent pelvic floor disorders. Repetitive strain and lifting harm the muscles, ligaments, and connective tissues, which can lead to PFD. Women should also learn how to properly use the arm and leg muscles to lift.
How Do Daily Activities Change IAP?
Until a few years back, the ability to study the relationship between IAP and pelvic floor disorders had been limited because researchers were unable to measure IAP outside the laboratory. Also, the standard fluid-filled rectal balloon catheter used in such studies was not conducive to real-world settings due to its limited mobility and poor dynamic response.
To overcome these limitations, a team of researchers developed a wireless intravaginal transducer (WIVT), which estimates IAP by measuring the pressure in the upper vagina. Using this WIVT, the intra-abdominal pressure of a number of women was measured while they lifted weights and walked at different paces in order to observe how IAP changed during certain activities.
In the study, titled “Effects of Walking Speeds and Carrying Techniques on the Intra-abdominal Pressure in Women,” the researchers measured the IAP of forty-six healthy women between the ages of nineteen and fifty-four while they lifted weights and walked.
The study was conducted when the women were not menstruating. Pregnant women, women within six months postpartum, and those who had been injured in the past three months were excluded from the study.
The women were instructed how to properly insert the WIVT and strap its monitor to their chests. The WIVT was allowed to adjust to body temperature for ten minutes. Baseline IAP readings were recorded while the women lay faceup and while they stood quietly for thirty seconds.
For the walking exercises, a standard distance of 400 m was selected. The women were first instructed to walk slowly (as if walking with a toddler or an old dog), then to walk at a medium speed (a normal pace), and then to walk fast (as if trying to catch a bus without running). IAP was measured throughout all these walking exercises.
For the lifting exercises, a weight of 13.6 kg (30 lbs) was selected. The weight of 13.6 kg was chosen because it is approximately equal to carrying a three-month-old infant in a car seat. The women had to pick up the weight, carry it for 100 m, and then put it back down.
The weight had to be carried in six different ways: backpack carry, in which the weight was carried like a backpack; double arm hang, in which the weight was divided equally between two grocery bags; side carry, in which the weight was carried sideways at waist level; front carry, in which the weight was carried in front with both arms level with the waist; combination carry, in which half the weight was carried in a grocery bag and the other half was carried sideways at waist level; and awkward carry, in which the weight was carried hanging on one side like a basket.
The Outcome of the Study
During the walking exercises, intra-abdominal pressure increased as walking speed increased. IAP was lowest when standing and highest when walking fast.
In the weight carrying exercises, IAP was significantly higher for the side, awkward, and front carry positions than it was for the backpack carry position. The lowest pressure was observed when the weight was carried in both arms and the participants squatted and grabbed the weights rather than bending at the waist and lifting with the arms.
Thus, women should evenly distribute any loads they carry and avoid fast walking while lifting heavy weights. Following these recommendations may help prevent pelvic floor disorders later in life.
Reference
Coleman, Tanner J., Nadia M. Hamad, Janet M. Shaw, Marlene J. Egger, Yvonne Hsu, Robert Hitchcock, Huifeng Jin, Chan K. Choi, and Ingrid E. Nygaard. “Effects of Walking Speeds and Carrying Techniques on Intra-abdominal Pressure in Women.” International Urogynecology Journal 26, no. 7 (2015): 967–974. Retrieved from: https://link.springer.com/article
