In addition to bearing the weight of the entire body, our feet take a beating in a variety of ways. We may injure them in an accident or shove them into shoes that turn them into fashionable contortionists. We may also suffer from a medical condition such as arthritis or bursitis.
While the majority of our foot pain can be explained by any one of these issues, another potential source should be considered as well: the spine.
Our spine is made up of 33 individual bones known as vertebrae that are joined together to form the spinal column. The vertebrae are numbered individually and broken down into five sections:
The first 24 vertebrae are moveable; the vertebrae located in the sacrum and coccyx are fused together.
Contained within the spinal column is the spinal canal that houses the spinal cord. Approximately 18 inches long and sporting the same thickness as our thumb, the spinal cord begins at the brainstem and ends at the first vertebra in the lumbar spine. From there, the spinal cord separates into what is known as the cauda equina (a bundle of nerve roots named for the resemblance to a horse’s tail) before branching off, forming the sciatic nerve that travels down along the legs and feet.
Sciatica is typically the cause when the lower back is the source of our foot pain. Sciatica is a condition in which the sciatic nerve or one of the associated nerves is impinged (pinched) or compressed. The pressure on the nerve results in pain radiating from the lower back to the leg and foot (known as radiculopathic pain). Lower back conditions that may cause sciatica include:
Herniated lumbar disc: Spinal discs are cushions between the vertebrae that give the spine its flexibility and stability. A disc herniation occurs when the soft center of the disc leaks out of a crack of the tough outer exterior and puts pressure on the nerves in the lower back.
Lumbar spinal stenosis: With lumbar stenosis, the spinal nerves in the lower back are compressed due to a narrowing of the canal in the spine housing, placing pressure on the spinal cord and cauda equine.
Spondylolisthesis: Symptoms of spondyloisthesis appear when one of the vertebrae of the spine slides out of place.
If foot pain is accompanied by leg pain or numbness, there’s a good chance that the pain is the result of a condition in the lumbar region of the spine. Depending on the condition, types of foot pain symptoms resulting from a lumbar spine condition include:
Difficulty walking on tiptoes: Pain on the bottom of the foot may be due to a condition with the sciatic nerve’s S1 spinal nerve root. The nerve root affects the calf muscle otherwise known as the gastrocnemius muscle, making it difficult to walk on tiptoes, raise the heel off the ground or do everyday activities like walking.
Foot drop: This symptom is characterized by weakness or heaviness that makes it challenging to flex the ankle and bring up the front of the foot.
In addition, foot drop resulting from an issue with an L5 nerve root will produce pain that radiates down the outside of the calf and over the top of the foot, ending at the big toe.
Heel walk: Heel walk is a limited ability to bring the foot upward and may be accompanied by numbness in the lower leg and foot. Heel walk may appear if one of the nerves connected to the sciatic nerve (a major nerve that begins in the lower back and extends down the back of the thigh) is affected.
If you suspect that your foot pain may be referred pain originating from a condition in your lower back, a specialist should be contacted. At New Jersey Neck & Back Institute (NJNBI), Spine specialist Sandro LaRocca is our board certified, fellowship-trained orthopaedic surgeon with years of experience and expertise in the diagnosis and treatment of spine disorders.
For more information or to schedule an appointment with Dr. LaRocca, contact NJNBI today or fill out our contact form.