A Look at Intraabdominal Pressure and Exercise Prescription
One of the benefits of two weeks close contact isolation has been an opportunity for me to spend some time going through research papers. I thought I would summarise the following study as it highlights why it is important to look at the individual in making decisions on exercise choices.
The relationship between intra-abdominal pressure and body acceleration during exercise.
Johanna D. de Gennaro, MS, Claire K. de Gennaro, MS, Janet M. Shaw, PhD, Tomasz J. Petelenz, PhD, Ingrid E. Nygaard, MD, MS, and Robert W. Hitchcock, PhD
Female Pelvic Med Reconstr Surg. 2019 May-Jun; 25(3): 231–237.
FULL ARTICLE: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5949233/
The authors studied 25 women aged 18-54 years with healthy weight, who have never been pregnant and who participate in regular strenuous exercise 3 or more times a week. The women were injury-free, not using a pessary and had not had pelvic surgery (excluding hysterectomy).
Women wore a wired intra-vaginal silicone transducer (23.9mm wide, 37.3mm long) placed in the upper vagina. The wire was attached to an accelerometer device worn on a waistband. They were assessed performing 13 different tasks and the intraabdominal pressure (IAP) was recorded. Each task was performed for 30sec apart from the 3 walking activities which were performed for 3min each. Below I have summarised a table that was included in their results.
|Activity||Overall average maximal intraabdominal pressure cmH20||Range of average maximal intraabdominal pressures (min-max)|
|Lying||16.7||4.6 – 27.2|
|Standing||36.7||21.6 – 52.4|
|Treadmill walking 2.74km/hr
|Treadmill walking 4km/hr
|54.5||35.7 – 76.9|
|Treaadmill walking 5.47km/hr
|68.5||46 – 102|
|Step – Up (height 20.3cm)||59.7||43.1 – 98.3|
|Step – Up (height 30.5cm)||68.7||48.5 – 101.1|
|Lifting 4.5kg from bench height 96.5cm to floor repetitions||48||30.3 - 89.6|
|Plank (forearms and toes)||49.1||23.3 – 94.8|
|Curl Ups||27.4||8.9 – 66.2|
|Full Sit ups||64.1||28.6 – 133.1|
|Pushups on knees||45.3||24.5 – 83.6|
|Walking Lunges||56.8||39.6 – 87.9|
|Walking Lunges with 4.5kg hand weights held by sides||57.7||40.9 – 90.8|
|Jumping jacks||124||77.5 – 188.6|
There is enormous variability in the pressure readings for the individuals in the study. If you take a look at the Curl Up task you can see the variation is 8.9 to 66.2cmH20. We know participants are of a similar weight and fitness and needed to satisfy the other study inclusion criteria so must consider what modifiable factors are creating the large difference in pressures. Performance technique, breathing and resistance to the movement could impact on pressure generated to achieve the task.
It is interesting that a plank on toes and forearms for 30sec recorded lower average pressure than walking at a 12% gradient at 4km/hr for 3min. It also generated less pressure than pushups on knees. Plank is an exercise that is contentious with suggestions it should not be performed for women with or at risk of pelvic organ prolapse or rectus diastasis. Once again you can see the large variation in average individual pressure with planks 23.3 – 94.8cmH20. So what is it in the task that allows some women to perform the activity with almost the same amount of IAP as simply standing? This study highlights how inappropriate it is to label exercises as Yes or No activities for women at risk of prolapse or with diastasis. We need to make decisions based on the individual, their history, body awareness, degree of stiffness, body dimensions, familiarity with activities and goals. It is also worth noting whether the transducer is measuring vaginal or abdominal pressure.
Let’s also consider the advice we provide women on lifting. Although weights used in this study were light it was interesting to see that there was no significant difference in performing walking lunges with no weight and with 9kg of weights held by the sides. Stepping up and down on a 20.3cm step, just higher than the rise on an internal staircase, created greater average IAP compared to lifting 4.5kg from bench to floor repetitively (though speed isn’t specified) .
An earlier study by Weir et al (2006) showed simply moving from sitting to standing without using your hands generated IAP of 79cmH20. The authors did demonstrate that increasing the weight being lifted does increase the pressure in the pelvic and abdominal cavity. Lifting a weight from the floor created the following IAP pressure readings: 5kg - 63cmH20, 10kg – 122cmH20, 15kg – 149cmH20).
There are many unanswered questions in the research regarding restrictions that we place on post-operative gynaecological and postnatal clients. Now that devices exist that can more readily record vaginal pressure there should be advances in the research that provide us with a better understanding and therefore advances in the care provided to our clients.
Sarah and I are committed to supporting women through all stages of life from pregnancy, birth, recovery to peri and postmenapausal. We aim to provide evidence-based exercise prescription and endeavour to modify our practices to reflect advances in knowledge.