When I was just starting my podiatry practice 35 years ago, I was young and fit with few aches or pains. However, now, in my seventh decade of life, I am feeling the effects of age with various mild painful mechanical issues intermittently occurring within my feet and lower extremities that I never had when I was younger.
Regardless of the inconvenience that these issues cause me, one benefit is that I can now better empathize with my older patients and their maladies. In fact, my own experiences with aging has led me to develop a better understanding of the significant effects that added years may have on the biomechanics of the foot and lower extremity, and the production of the characteristic injuries that develop in many older adults.
One of the most significant effects of aging on the human foot is plantar fat pad atrophy. Plantar fat pad atrophy occurs with increasing frequency in older adults and is due to a reduction in the integrity of the highly specialized plantar fat pad tissue in their heels and forefeet that protects their plantar foot structures from the impact forces of weightbearing activities.
In 2005, researchers from Taiwan found that forefoot fat pads in elderly individuals were stiffer and less able to respond to different impact velocities than in younger individuals.1 In a study by Korean researchers, 14.8 percent of 250 patients with plantar heel pain may have had an etiology of plantar fat pad atrophy.2 In another study involving a group of 200 adults, researchers demonstrated that shock absorption of the heel fat pad decreased with age.3
Therefore, there is good research evidence that atrophy of the plantar fat pad may lead to painful symptoms within the plantar heel and forefoot over time. An atrophied plantar fat pad will absorb less impact energy with each foot strike, which may lead to plantar heel and forefoot injury and pain. Even though there have been attempts over the years to augment the plantar fat pad with injectable silicone to try and replace its cushioning properties, research shows that injectable silicone may migrate to other areas of the plantar foot over time, including distant lymph nodes.4
I have personally experienced the gradual and uncomfortable thinning of the plantar fat pads within my own feet over time. I am currently unable to walk comfortably barefoot on hard surfaces over long periods. In addition, over the past few decades in my clinical practice, I experimented with different solutions for my patients who suffer from plantar heel and forefoot pain due to plantar fat pad atrophy. I believe it may be helpful to share my own anecdotal observations that could be of benefit to patients who also suffer from this painful condition.
First of all, in my own patients with plantar fat pad atrophy, I recommend that they wear a cushioned sandal, especially on hard surfaces, and avoid barefoot activities. My current favorite cushioned sandals are OOFOS®, which I find provide the best relief of plantar heel and forefoot pain of any currently available sandal for my patients. Secondly, I recommend “maximalist” running or walking shoes with thick, cushioned midsoles for my patients with painful plantar fat pad atrophy to help cushion the impact forces of weightbearing activities.
Finally, I will add an extra-thick topcover, with at least a six mm layer of neoprene or Poron®, in the custom foot orthoses that I prescribe for this patient population. In addition, I use an orthosis shell made of ethyl vinyl acetate (EVA) or Plastazote® for extra cushioning in custom foot orthoses for these patients. This extra thick layer of orthosis cushioning helps most patients with plantar foot pain but may require a half shoe-size increase in order to accommodate the increased thickness of the device.
From my clinical observations of patients and experience with my own aging feet, I am now better able to help my older patients with plantar fat pad atrophy. Even though getting older is not without its problems, it is very gratifying to have patients appreciate my age and clinical experience since having more years under my belt has improved my ability to make my patients’ feet more comfortable so their lives can return back to normal.
It is nice to see that being a “mature” podiatrist still has its benefits for me and my patients.
Dr. Kirby is an Adjunct Associate Professor within the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University in Oakland, Calif. He is in private practice in Sacramento, Calif.
1. Hsu CC, Tsai WC, Chen CP, et al. Effects of aging on the plantar soft tissue properties under the metatarsal heads at different impact velocities. Ultrasound Med Bio. 2005;31(10):1423-1429.
2. Im Yi T, Lee GE, Seo IS, Huh WS, Yoon TH, Kim BR. Clinical characteristics of the causes of plantar heel pain. Annals Rehab Med. 2011;35(4):507-513.
3. Jørgensen U, Larsen E, Varmarken JE. The HPC-device: a method to quantify the heel pad shock absorbency. Foot Ankle. 1989;10(2):93-98.
4. Bowling FL, Metcalfe SA, Wu S, Boulton AJ, Armstrong DG. Liquid silicone to mitigate plantar pedal pressure: a literature review. J Diabetes Sci Technol. 2010;4(4):846-852.