When people develop persistent pain on the inside or underneath the heel, the diagnosis is often assumed to be plantar fasciitis. While plantar fasciosis is certainly one of the most common causes of heel pain, it is not the only possibility. One condition that is frequently overlooked is Baxter's nerve entrapment, a disorder that can produce symptoms very similar to plantar fasciosis and may even occur alongside it.
Baxter's nerve, also known as the first branch of the lateral plantar nerve, is a small nerve that supplies sensation and muscle function within the foot. As it travels along the inside of the heel, it passes through several narrow anatomical spaces where it may become compressed or irritated. When this occurs, pain develops as a result of nerve irritation rather than degeneration of the plantar fascia itself.
One of the reasons Baxter's nerve entrapment is commonly missed is that its symptoms overlap considerably with plantar fasciosis. Patients often describe pain beneath the heel, discomfort during walking, tenderness around the inside of the heel and difficulty standing for prolonged periods. Because these symptoms resemble plantar fasciitis, many people receive months of stretching exercises, orthotics, anti-inflammatory medication or shockwave therapy without significant improvement because the underlying problem has never been identified.
Unlike plantar fasciosis, which involves degeneration of the plantar fascia, Baxter's nerve entrapment is a neurological condition. Nerves behave differently to tendons and ligaments. When compressed or irritated, they may produce burning pain, aching, tingling, numbness or pain that radiates into the arch of the foot. Some patients notice that the pain changes throughout the day or worsens after prolonged standing, while others experience discomfort that is less predictable than the classic "first-step" pain associated with plantar fasciosis.
The relationship between plantar fasciosis and Baxter's nerve entrapment is particularly important. Chronic thickening of the plantar fascia, altered foot biomechanics or surrounding soft tissue changes may contribute to irritation of the nerve. In some patients, both conditions are present simultaneously. If only the plantar fascia is treated while the irritated nerve is overlooked, heel pain may persist despite otherwise appropriate treatment.
Accurate diagnosis therefore becomes essential. A careful clinical examination often provides important clues, but imaging may also be valuable. High-resolution diagnostic ultrasound allows the plantar fascia and surrounding soft tissues to be assessed dynamically and may identify changes that suggest nerve irritation or exclude other causes of heel pain. MRI may occasionally be recommended when more complex pathology or muscle changes are suspected.
Recognising Baxter's nerve entrapment is important because the treatment differs from that of plantar fasciosis. Although some conservative measures overlap, management may also include techniques specifically designed to reduce nerve irritation. In carefully selected patients this may include ultrasound-guided hydrodissection, a procedure that aims to gently separate the nerve from surrounding tissues to improve its mobility and reduce compression. Surgery may occasionally be considered when significant nerve entrapment persists despite appropriate non-surgical treatment, although this is relatively uncommon.
The key message is that persistent heel pain should never be assumed to be plantar fasciitis simply because it is painful beneath the heel. Establishing the correct diagnosis is the foundation of successful treatment. When heel pain fails to improve as expected, it is often worth asking whether another condition—such as Baxter's nerve entrapment—may be contributing to the symptoms.