In this issue, our response was written by Podiatrist Phil Schrumpf, DPM,
of the Active Feet Clinic in Missoula, Montana. Dr. Schrumpf, who got his degree
in 1994, trained at Kaiser Permanente, in Oregon and California.
Question: I am 85 years old, and have had Type 2 diabetes for 49 years. I presently take Lantus insulin and several oral medications. My problem is my feet. My doctor prescribed “extra depth shoes,” and I have them. But I’m developing little lumps on the bones on the bottom of my feet—and they hurt like stepping on glass. Why is this happening? What should I be doing?
Answer: The “little lumps” on the bottom of your feet are the metatarsal bones in the front of your foot becoming prominent or painfully noticeable due to two common reasons:
First may be the development of diabetic peripheral neuropathy. This causes numbness and muscle weakness. It may also affect your proprioception, which is the sensory means by which your body keeps track of its parts. Your diminished ability to feel and direct movement of your feet, combined with your muscles’ inability to stabilize the toes, creates a muscle and tendon imbalance leading to the development of contracted toes. We call this hammertoe (see related story on hands). Once the toes contract, the pressure forces the bones back and down, making the lumps noticeable on the bottom of your feet. With the development of these bumps, you are at risk of developing an overuse injury due to lack of padding.
The second reason has to do with the displacement or atrophy of the fat pad on the bottom of your feet. Displacement occurs from the force caused by contracting of the toes. This important fat pad is pushed towards the toes, creating lack of cushion or protection on the bottom of your feet. Atrophy of the fat pad is also common with age, and there is no way to reverse damage to or replace this fat pad.
“What should I be doing?” is an important question. Wearing extra-depth shoes, which allows extra room for the contracting toes and prevents pressure to the top of your toes, is absolutely the right first step. In addition, extra-depth shoes will accommodate multiple-density insoles, which form to your feet. These accommodative insoles distribute the pressures along the bottom of your feet equally, to balance and protect the prominent lumpy areas from developing an injury such as ulceration. Adding these inside the extra-depth shoes should be your next step.
You’re on the right track. Ask for conforming insoles and have regular follow-ups with your doctor and your podiatrist. Make an extra visit if the lumps become more pronounced or painful, or if you can’t sense the bottom of your feet at all.
NOTE: If you have any questions for “Ask the Doctor,” please send them to the Voice editorial office. The only questions Dr. Wilson will be able to answer are the ones used in this column.