The pelvis is part of your movement chain
For many years we have overlooked the role of the muscles in the pelvis both for pain and co-ordination of movement between trunk and limbs. The musculoskeletal system is a delicate balancing act, allowing the forces from the weight and the motion of your arms and trunk to be transferred to the legs. The pelvis, of course, is in the middle. More that 50 muscles attach to the pelvis on the inside as well as the outside. They function together for stability, but the internal muscles are also part of sexual function and continence of both bowel and bladder.
Injuries to the pelvis can cause some muscles to shut down and others to compensate and become too active. In general, symmetry in the body is ideal. Asymmetrical postures can lead to muscles and their connective tissues becoming longer or shorter than ideal and increasing or decreasing the way they pull and support.
For instance, part of a bundle of muscles in the back will attach to the sacrum, the central bone in the pelvis where the tailbone attaches. A bit too much pull can shift the sacrum. Other muscles that attach to the sacrum then also shorten or lengthen to compensate. Rolling back into a slouch is one habit that tends to shorten the muscles attaching to the tailbone. Those muscles can develop excess tone (too much activity) and become painful as well, usually causing pain when sitting. Weakness in the front of the pelvic muscles can be part of the pattern contributing to that imbalance after vaginal deliveries. Sitting with legs crossed or rotated (for example, to focus on a computer screen to one side) will cause similar muscle imbalance. When you stop and think about a knee injury or ankle sprain, you realize how much a few weeks of limping can impact muscles all the way up the leg. Small, nagging foot and knee dysfunctions can shift the symmetry of muscle patterning causing low back pain and even transferring the forces up into the thorax. Sometimes these persist long after the original injury. People may be aware that they tend to stand or sit asymmetrically, but have not been able to shift back to a more neutral posture.
There is increasing evidence in research on low back pain (LBP) that the function of the pelvic floor is a key component. The diaphragm is also part of the co-ordinated system of core muscles that creates the necessary internal pressure to stabilize the spine.
“Squeeze your pee muscles!” is a phrase I hear often, but some of the research now points to overactivity of the pelvic muscles being a more common cause. Approximately 40% of women in one study were not able to contract their pelvic floor muscles correctly. Clinical experience suggests that men might be a little further ahead, but poor synergy (ability of muscles to work together) of the back, abdominals, diaphragm and pelvic muscles is more common in those with low back issues or pelvic pain. Often, when people have struggled with low back pain for years and have never really been able to ‘fix’ it, there is a pelvic component. Incontinence or sexual dysfunction are frequently clues. Pelvic floor physiotherapy with an orthopedic focus can help tease out the factors to strengthen the muscles that actually need it and learn to relax the muscles that are tight.