Low back pain is one of the most common musculoskeletal conditions; up to 80% of people will experience low back pain at some point in their lives. There are many causes of low back pain, and most respond well to conventional treatment including orthopedic physiotherapy, chiropractic, and/or massage. In many cases low back pain arises from trigger points in the stabilizing muscles, disc issues, joint immobility, or some combination. However, if you have been experiencing low back pain that doesn’t seem to improve with the treatment interventions listed above, perhaps your pelvic floor muscles are contributing to your low back pain.

Previously, it was believed that BMI and physical activity levels were correlated with low back pain. Recently, research has shown breathing and continence have stronger links to low back pain than previously thought.

What Causes Low Back Pain?

There are several hypotheses for the development of low back pain. One leading mechanism is due to changes in control of the trunk muscles [1] [2]. Trunk control relies on coordination of muscles like the diaphragm (breathing), deep core muscles like transversus abdominis, and pelvic floor muscles (continence) [3]. However, these muscles aren’t only responsible for stabilizing the spine. The diaphragm and transversus abdominis control breathing and posture, and the pelvic floor muscles help control continence. In people with respiratory disease, the postural function of these muscles becomes impaired as well. Similarly, dysfunction of the stabilizing role of the pelvic floor may be apparent in women with incontinence [4].

Overall, it is believed that the reduced capacity of these muscles affects the mechanical support of the lumbar spine. This make sense – if these muscles can’t fulfill their main function, how are they supposed to help stabilize the spine?

How Do Breathing and Pelvic Floor Relate to Low Back Pain?

Research shows that BMI and physical activity are not consistently associated with low back pain in women (age 18-75) [5]. Middle aged and elderly women with higher BMI (i.e. overweight and obese) and lower physical activity levels did report experiencing low back pain more often.

Incontinence has been associated with low back pain across all ages. There are a couple of explanations for this:

First, people with incontinence are more likely to be obese and less physically active [6], [7] [8]. This is likely due to the impacts on quality of life seen in people with incontinence; it can affect self-esteem, confidence, mental health, and participation in social and physical activities.

Second, 78% of women with low back pain also had urinary incontinence, which links to pelvic floor muscles in lumbopelvic stability [9]. Similarly, people with respiratory issues tend to be more sedentary because they are less able to exercise due to their breathing difficulties [10].

Summary

Previously, BMI and physical activity were closely linked to low back pain. Emerging research is showing that incontinence and respiratory diseases are more strongly associated with low back pain than BMI or physical activity. Previous research may have been confounded by only looking at BMI and physical activity as causes, rather than looking at WHY people have a higher BMI or are less physically active. As mentioned above, people with incontinence tend to have a higher BMI and are less physically active. This is likely due to the impact incontinence has on physical and mental health, and overall quality of life. Similarly, people with respiratory diseases tend to be more sedentary and less physically active due to breathing difficulties experienced with exercise. While previous studies linking BMI and physical activity to low back pain aren’t faulty, perhaps they weren’t explaining the entire picture.

If you’ve been experiencing low back pain that just doesn’t seem to be getting better, and you’re also experiencing incontinence, our pelvic floor physiotherapist is here to help!