Calcaneal and Plantar Nerves: Overlooked contributors to heel pain syndromes?

So I'm sitting here in my living room watching coverage of the latest impending apocalypse (Hurricane Ike) churn in the Gulf. You might think it's an odd time for this Gulf Coast native to be thinking about heel pain, but here I am...thinking about heel pain. We can discuss the reasons I have no life at a later date.

Diagnoses seem to come in spurts in this clinic and I've recently been referred several cases of both infracalcaneal and retrocalcaneal heel pain. As with many of my treatment approaches, my tactics regarding heel pain have evolved considerably over the years. Despite this ongoing refinement, I still find heel pain to be both fascinating and frustrating clinical entity. For me, it is the LBP of the foot.

I recently did a literature search on the various incarnations of heel pain and was relieved to find I'm not the only one out there navigating through the fog. There are still gaping holes in our knowledge and understanding of this condition. In the midst of my literature search, one article stood out enough that I felt it worth mentioning.

Overview and Methods

The article was published in 2003 in the Journal of Foot and Ankle Surgery. The authors set out to determine if sensory abnormalities existed in the medial and lateral calcaneal nerve distribution in patients suffering from plantar heel pain. The study examined 97 feet in 82 patients reporting symptoms consistent with plantar fasciits including poststatic dyskinesia and tenderness to palpation along the medial calcalneal tubercle. Patients were excluded from the study if they had comorbidities such as radiculopathy or an equinus foot. Neurosensory testing was performed using a pressure-specified sensory device used to detect compression or entrapment of both large and small nerves.

Results and Conclusions

The authors found a significant number of patients with plantar heel pain display abnormal sensibility within the branches of the posterior tibial nerve. Abnormal sensibility was noted particularly within the medial calcaneal nerve (P<.0008) and lateral calcaneal nerve (P<.0001).

It is our belief that entrapment of the MCN plays an important role the development of plantar heel pain, and we were able to quantify abnormal sensibility in the cutaneous distribution of both the MCN and/or the MPN in a significant number of patients with plantar heel pain. The observed nerve dysfunction is most likely secondary to entrapment of the nerve trunk, or trunks, as a result of repetitive mechanical irritation. In response to this pathologic stimulus, we hypothesize that the injured nerve trunk undergoes in-continuity fiber disruption and intra- and perineural fibroplasia. Because 49.48% of our patients displayed abnormal sensibility in the cutaneous distribution of both the MCN and MPN, a proximal neural origin such as proximal tarsal tunnel entrapment of the PTN, or even lumbosacral radiculitis, plexopathy, or sciatic nerve impingement, should be considered in these patients.

Clinical Implications?

A treatment theme that seemed to resonate with me in this article was that of regional interdependence. For example, two of my patients with heel pain also have persistent lumbar pain - one with motor radiculopathy ipsilateral to the heel pain. These comorbidities may play more of a role in distal pathology than previously appreciated. Secondly, the findings of this article could lend support to the notion that neurodynamic movements such as lower extremity nerve gliding could play a role in more distal conditions such as heel pain. In addition to our traditional mechanically-based therapeutic regimen, it may make practical sense to consider structures such as the peripheral neural tree as possible contributors to the patient's problem.

Here's hoping all my neighbors along the Gulf Coast stay dry this weekend!

Rose JD, Malay DS, Sorrento DL (2003). Neurosensory Testing of the Medial Calcaneal and Medial Plantar Nerves in Patients With Plantar Heel Pain The Journal of Foot and Ankle Surgery, 42 (4), 173-177