Foot pain is a prevalent issue affecting people of all ages and lifestyles. Given the complexity of the foot’s structure, which comprises 26 bones, 33 joints, and over 100 muscles, tendons, and ligaments, with up to five times the load of the patient’s body weight going through the foot and ankle, it’s not surprising that many people experience foot pain at some point in their lives.
Foot pain can result from numerous factors including injury, overuse, obesity, congenital and acquired deformities, medical conditions, and improper footwear.
Common causes
Plantar fasciitis, a leading cause of foot pain, is also one of the most difficult to treat successfully. It occurs when the plantar fascia, a thick band of tissue running across the bottom of the foot, becomes inflamed and degenerative.
Contributing factors include flat feet, tight calf muscles, excessive loads (i.e. being overweight), repetitive strain or overuse. Symptoms include sharp, stabbing pain in the heel, especially in the morning or after long periods
of rest.
An important differential diagnosis is tarsal tunnel syndrome, which can be distinguished by taking a pain history and performing a Tinel’s test around the tarsal tunnel to see if the pain is reproduced. The plantar heel spur seen on x-rays is not the cause of plantar fasciitis, but a sign of long-term stress on the plantar fascia and deep muscle layers of
the foot.
Achilles tendinopathy affects the Achilles tendon either at its insertion into the calcaneum or in the tendon substance, or both. It is often caused by overuse, sudden increases in physical activity, or improper footwear, leading to pain and stiffness in the back of the heel. It is common in the middle aged, patients with diabetes and overweight individuals.
Hallux Valgus (Bunions) result from exposure of the medial first metatarsal head. Hallux valgus occurs when there is widening between the first and second metatarsals (primary metatarsus varus) resulting in lateral subluxation of the sesamoids and resultant lateralisation of the flexor and extensors to the big toe.
The big toe is pulled laterally and can then push against the adjacent toe, causing hammer toe deformities of adjacent lesser toes, most commonly the second toe. The uncovered medial first metatarsal head rubs on shoes sustaining microtrauma and bursal thickening and ossification, known as bunions. This condition can cause significant discomfort, particularly when wearing tight or narrow shoes.
Hallux rigidus is a degenerative arthritic process resulting in pain and a functional limitation of motion of the first metatarsophalangeal joint. It can be the result of trauma, repetitive micro-trauma or anatomical variants in the first ray.
Metatarsalgia is characterised by pain (worse with activity) and inflammation on the plantar aspect of the metatarsal heads, often resulting from high-impact activities, forefoot deformities or wearing poorly fitting shoes.
Stress fractures are typically caused by repetitive force or overuse. Common in athletes and those engaged in high-impact sports, symptoms include localised pain, swelling, and tenderness that intensifies with activity.
Morton’s neuroma is a compressive neuropathy involving thickened tissue around a nerve or swelling and fibrosis of the nerve itself, causing pain, tingling, or numbness between the toes. The most common site is between the third and fourth toes (third webspace) but can involve all web spaces.
It is seen commonly in middle-aged woman with narrow, long feet that have always had problems finding appropriate fitting shoes. Radiographically, there is little room between the metatarsal heads where the interdigital nerves run.
Pes planovalgus (flat feet) may cause discomfort due to tibialis posterior tenosynovitis or sinus tarsi/sub-fibular impingement, while cavovarus (high arches) can increase pressure on the lateral aspect of the heel and plantar forefoot. These conditions can lead to arthritis of multiple foot joints.
Arthritis can also cause significant foot pain.
Investigations
Accurate diagnosis of the underlying cause of foot pain is essential for effective treatment. A targeted medical history is crucial in understanding the nature, duration, and onset of foot pain. Focus on the patient’s pain profile (level of pain, pain at rest, mechanical, resting or neuropathic, exacerbating and relieving factors), activity level, medical conditions, and any recent injuries.
A physical examination should assess the hindfoot alignment (valgus, neutral or varus), foot’s appearance (flat or high arched, bunions, callosities), range of motion, and areas of tenderness or swelling. A documented neurovascular assessment of the limb, height and weight (BMI) is imperative.
Weight bearing foot and ankle X-rays are the cornerstone to detect fractures, dislocations, arthritis and deformities. Magnetic resonance imaging provides detailed images of cartilage and soft tissues, including muscles, tendons, ligaments, and nerves. It is particularly useful for diagnosing conditions like arthritis, tendinopathies, plantar fasciitis, neuromas and stress fractures.
Ultrasound is often used to assess conditions such as tendonitis, bursitis, neuroma and plantar fasciitis. My preference before surgical intervention is obtaining a more detailed MRI especially in neuroma surgery. Ultrasound is most useful for guiding local anaesthetic/corticosteroid injections into specific areas for diagnostic and therapeutic purposes.
A CT scan provides detailed cross-sectional images of the foot, which can help diagnose and classify fractures or assess bone abnormalities not clearly visible on x-rays. A weight bearing foot and ankle CT provides even better structural imaging in complex foot and ankle deformities when planning surgery using 3D modelling.
Blood tests are useful for markers of inflammation (WCC, CRP, ESR) or autoimmune disorders, such as rheumatoid arthritis or gout. Nerve conduction studies and EMG have little use in the diagnosis of foot pain. A bone scan may be recommended to detect stress fractures, infections, or bone tumours that are not visible on standard imaging. Rarely a biopsy of the skin, tissue or bone may be performed if there is suspicion of infection, tumour, or certain types
of arthritis.
Key messages
- Foot pain is common and has many causes
- Accurate diagnosis starts with history
- Weight bearing x-rays is first line imaging.
Author competing interests – nil