What Is Foot Pain?
Table of Contents
Cause Of Foot PainMany cases of foot pain can be traced to the sensory nerves that serve these extremities. These are mainly lumbar or sacral nerves. Damage or inflammation of the nerves of the foot may be perceived as pain. This may be associated with many variables, including lower back injuries. Complex regional pain syndrome is a condition in which symptoms such as chronic pain, reduced motion, and sensory deficits affect an extremity such as the foot. Some tumors, or treatments that reduce their size (i.e. chemotherapy or radiotherapy), may cause mechanical damage to the nerves serving a foot, leading to chronic pain. Failed back surgery syndrome is a condition in which nerves are inadvertently damaged in the course of spinal surgery, resulting in pain in a lower extremity.
Foot pain may also be caused by direct damage or injury to the body part. This may be incurred from occupational hazards such as prolonged standing, or from wearing ill-fitting, tight, or high-heeled shoes. Wear and tear from strength or endurance training may also be a source of damage to the feet. In addition, patients with certain genetic disorders such as Charcot-Marie-Tooth syndrome typically develop deformities of the foot that may be associated with chronic pain. Conditions associated with the release of excessive inflammation, such as rheumatoid arthritis, may also result in foot pain.
Treatments For Foot PainPhysical therapy is thought to be beneficial for patients with foot pain. This treatment may improve other symptoms such as reduced mobility, joint stiffness, or tendonitis. Physical therapy typically involves a program of exercises, stretches, and muscle conditioning. This treatment may be useful for patients in need of rehabilitation after an injury, and has been shown to reduce pain while restoring the normal function of the limb.
Patients wishing to treat their own chronic foot pain may be advised to start with conventional options, such as drug therapy. These may include non-steroidal anti-inflammatory drugs, such as naproxen or aspirin. These drugs inhibit the formation of inflammatory molecules in the body, thus offering some relief in cases of arthritis or injury. Inflammation may also be controlled with oral steroids. These, however, are associated with side effects such as changes in bodyweight, increased irritation or other emotional problems, gastrointestinal disorders, and organ damage. The probability of these side effects increase with regular intake over time.
Opioids, a drug class including commonly-known painkillers such as morphine, may be administered to those in severe pain, such as failed back surgery syndrome patients. Opioids inhibit pain receptors in the body, and are thus a gold standard in extreme pain treatment. However, they are associated with a relatively high risk of addiction, abuse, and drug tolerance. Therefore, they are prescribed with caution, often after patient education on safe and responsible opioid use.
The lumbar or sacral nerves serving the feet may also be temporarily numbed to inhibit moderate to severe foot pain. This may be achieved through the injection of local anesthetics (e.g. bupivacaine) into the vicinity of these nerves. These injections, known as nerve blocks, may also contain steroid medications that reduce inflammation if present. Nerve blocks are effective, but may result in adverse events such as chest numbness and headache. Other rarer side effects include the loss of motor control or sensation.
Steroids (often in combination with local anesthetics) may be injected directly into a joint (i.e. the ankle) that is the source of chronic pain. These joint injections are common treatments for patients with arthritis experiencing moderate to severe pain. They may result in short- to medium-term pain relief, and may need to be repeated regularly for maximal effects. The side effects of these procedures are similar to those for oral steroids, and may also include short-term immunosuppression.
Radiofrequency ablation is a more long-term method of nerve blocking. In this procedure, the nerve associated with pain is located using imaging techniques. A thin probe is inserted (under local anesthetic) until it reaches the nerve. The probe will then deliver radiofrequency impulses, disrupting specific areas of the nerve associated with pain signaling.
The risks of radiofrequency ablation include the small probability that the probe will also inadvertently disrupt other parts of the nerve that control sensation. Other risks include bleeding and infection in the tissues through which the probe was inserted, discomfort, and the failure to achieve pain relief. However, radiofrequency ablation may result in a number of months’ worth of pain relief.
Another long-term option for chronic, treatment-resistant foot pain may be spinal cord stimulation of the lumbar nerves associated with the condition. This procedure involves the implantation of a small device near the spinal cord that interrupts pain signals by emitting electrical impulses. The risks of spinal cord stimulation include the accumulation of scar tissue near spinal nerves, which may in turn lead to chronic pain, movement of the implant away from its proper location, and failure to elicit the desired effect. Spinal cord stimulation is safe and effective in the vast majority of patients treated, however.
ConclusionFoot pain may profoundly affect normal function and movement. It may be associated with a wide range of factors, including conditions such as arthritis, injury, mechanical damage, and nerve damage. As foot pain is processed by sacral or lumbar nerves, many treatments for this type of pain may target them directly. These include nerve blocks, spinal cord stimulation, and radiofrequency ablation. Other treatments include steroid therapy and joint injections, for cases of foot pain related to arthritis.
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