Pronating Feet to Blame for Back Pain
Nicola Garrett | September 26, 2013.
Rolling your feet inwards when walking could be the cause of lower back pain, but only if you’re a female, researchers say.
The latest findings from almost 2,000 people taking part in the Framingham Foot study found that pronating feet when walking was significantly associated with low back pain in women, even after adjusting for age, weight, smoking and depression.
In contrast to what the authors expected to find, neither foot posture nor asymmetry in foot posture or function showed an association with low back pain.
Writing in Rheumatology, the international team including researchers from La Trobe University in Melbourne said the mechanics behind their findings could be explained by the kinematic interaction of the lower extremity joints during walking.
When the foot pronates during the early phase of gait the calcaneus everts while the talus adducts and the plantar flexes, they explained.
This induces an internal rotation of the tibia, which in turn leads to an internal rotation of the femur.
“In theory this increase in internal rotation of the femur results in anterior pelvic tilt due to the tight fibrous connection provided by the sacroiliac joint,” they wrote.
And although these movements were considered a normal part of walking, it was possible that greater stresses on on the lumbo-pelvic region could cause low back pain in individuals with excessive foot pronation.
Why this phenomenon only appeared to occur in females was not known, but could possibly be down to gender differences in the alignment, range and function of lower limb and spinal joints, the study authors said.
The findings provide preliminary evidence of a “postural-structural-bio-mechanical mechanism” underlying low back pain.
“Interventions that modify abnormal foot function, such as orthoses may have a role in the prevention and treatment of low back pain,” they concluded.