A recent study published in the Journal of the American Podiatric Medical Association looked at limb-length discrepancy as a cause of plantar fasciitis. The article, written by Mahmood et al., analyzed 26 patients with unilateral heel pain that was previously diagnosed as plantar fasciitis. The limb-length of the patients was then measured, using a combination of methods. The results of the study showed that there was a strong correlation between a longer limb and unilateral plantar fasciitis pain.
Taking a further look at the results of the study, it was found that the vast majority of the unilateral heel pain was found on the same side of the body as the longer limb. Presumably, a longer limb would function in a more pronated position during stance. This would put extra strain on the plantar fascia, the large, thick strip of aponeurosis running along the bottom of the foot.
The study also looked at Body Mass Index (BMI) as a possible cause of plantar fasciitis, however, the results were not significant for these two factors to be correlated.
Plantar fasciitis is one of the most common conditions that podiatrsts see, and is the most common cause of heel pain in the adult population. There are a number of different theories on why it develops, most of which focus of the biomechanics of the foot and lower extremity. This study by Mahmood et al. is one of few peer-reviewed journal articles to research the etiology of the common disorder.
Treatments for planar fasciitis are as numerous as the possible causes of the problem. Conservative therapy includes things like stretching, ice, rest, temporary arch supports/padding, night splints, functional orthotic devices, and oral anti-inflammatory medications such as NSAIDs. Other measures may include corticosteroid injections, extracorporeal shockwave therapy (ESWT), or platelet-rich plasma (PRP) therapy. Still more drastic measures may include surgical intervention, when all other conservative therapies have failed.
The authors of the study highlight an important decision in the possible treatment of plantar fasciitis associated with a limb-length discrepancy. That is the use of a hell lift in addition to the use of a functional orthotic device. The hell lift addresses the difference in limb length, which may be the etiology of the condition. Thus, the treatment would address the root of the problem, and not merely the symptoms.
More research into the etiology of plantar fasciitis is warranted, as this is an extremely common condition. Limb-length may be just one of many possible causes, and more studies like this one will be needed to determine them.
