Pain Below the Knee: Foot, Ankle, Calf, and Nerve Pain

Most calf, ankle, and foot pain is fairly straightforward to diagnose. So when someone comes to a pain specialist for pain below the knee, it usually means one of three things: the pain is unusual, something common was overlooked, or the pain is actually coming from elsewhere — such as a herniated disc in the back. Here's the territory.

Toes and forefoot

Besides ingrown toenails, bunions are the most common toe problem — the big toe drifting toward the others, often from tight or high-heeled shoes — helped by anti-inflammatories, a cortisone injection, wider shoes or an orthotic, and sometimes surgery. Arthritis of the big toe can come from gout, rheumatoid disease, or wear. In the forefoot, metatarsalgia covers general forefoot pain, and Morton's neuroma — a pinched nerve between the third and fourth toes — is a classic, treatable cause.

Sole and heel

Plantar fasciitis is the big one: pain in the sole and inner heel that's worst with the first steps in the morning and eases with activity, from inflammation of the tough fascia lining the foot's underside. Painful heel syndrome is similar but centered in the heel, more common in people who stand a lot. With any heel pain, an X-ray checks for a bone spur. The heel's fat padding also thins with age, which can make walking painful on its own.

Ankle

Most ankle pain is a sprain — damaged ligaments, most often on the outside of the ankle. Tendons around the ankle can also become inflamed. One condition worth knowing is osteochondritis dissecans, which can follow repeated sprains: a small fracture, sometimes missed on routine X-rays, that causes aching and a "catching" sensation with motion.

Calf

Chronic calf pain usually traces to muscle injury or spasm, circulation problems (in either the arteries or veins), or pain referred from the ankle, knee, or back. A careful exam usually finds the source.

When it's the nerves: pain in the whole foot or leg

This is where specialist care matters most.

Peripheral neuropathy — damage to the small nerves — most often comes from repeated toxic exposure, and the most common toxin is high blood sugar (diabetes), followed by alcohol and chemotherapy. It usually comes on gradually as a burning pain, often described vividly: feeling like you're walking on marbles, difficulty on slick floors, even bedsheets over the feet being painful. (Our diabetic nerve pain page covers this in depth.)

Complex regional pain syndrome (CRPS) deserves special attention, because early treatment changes everything. It's a burning, aching pain that starts in a small area — often the foot — and can march up the limb, with the skin so sensitive that light touch or cold is excruciating. It comes in two types: Type I (RSD, reflex sympathetic dystrophy), which follows an injury or even routine surgery with no identifiable nerve damage, and Type II (causalgia), which involves a known nerve injury. Early on the limb is red, swollen, and sweaty; over time it can turn cold, thin-skinned, and weak. Vigorous physical therapy is the mainstay and the only known cure — the goal being to keep the limb in use — and because therapy itself can be intensely painful, we sometimes numb the area with a continuous catheter of local anesthetic to make it possible. When the sympathetic nervous system is driving the pain, sympathetic nerve blocks can help; medications (topicals, anticonvulsants, antidepressants) and, in resistant cases, spinal cord stimulation round out the options.

Phantom limb pain after amputation is a form of "central pain" — the nervous system generating pain from a limb that's no longer there. Nearly all amputees feel sensations from the missing part; a smaller share feel true pain, which can be crushing, burning, or shooting. Interestingly, using epidural anesthesia for the amputation itself may lower the chance of developing it. Treatment centers on a well-constructed stump, a well-fitting prosthesis, good circulation, and finding and treating any trapped nerves, supported by medications.

If you have leg or foot pain and no one has found the source, call Newport Pain Management at (949) 759-8400.