What is plantar fasciitis?

Plantar fasciitis refers to pain on the sole of the heel, that primarily involves a ligament-like structure that runs under the bottom of the foot called the plantar fascia. This condition is also known as plantar heel pain or heel spurs. It is one of the most common conditions affecting the foot, and will affect 1 in 10 people. Plantar fasciitis is more common in females, people aged between 45 and 65, and athletes.

There are several theories about what causes plantar fasciitis. A common theory is that small amounts of trauma from mechanical stress in combination with altered blood supply changes the area where the plantar fascia inserts on to the heel bone. Usually, small amounts of trauma from mechanical stress will repair without problem. However, with an accumulation of excessive episodes of mechanical stress, the repair process fails leading to pain.

Although the plantar fascia is the most common cause of pain in the bottom of the heel, there are several other conditions that may cause pain in the bottom of the heel. A brief overview of these other causes is provided below.

Plantar Fascia tear

Rarely people will experience a tear in their plantar fascia. This usually happens during an activity and is felt as a sharp pain in the arch. There may be some swelling or bruising in the arch if there is a tear in the fascia.

Plantar fibroma

A plantar fibroma is a small nodule that can develop within the plantar fascia. They are more likely to occur in the arch, but some can occur close to the heel. Although the term ‘fibroma’ might sound menacing, they are benign and usually do not cause pain if they are not irritated.

Fat pad injury

There is a pad of fat beneath the heel that helps to protect the heel bone during gait. This is a specialised type of fat that is excellent at absorbing shock, which is comprised of a honeycomb-like network of connective tissue with fat in between. For some people, the connective tissue of this network can break-down and cause pain.

Nerve compression

There are several nerves in the foot, and some on the bottom of the heel that may become compressed. Repetitive compression of these nerves may cause pain in the heel. People often report pain that “shoots” within the foot or feels like an electric shock.

Calcaneal stress fracture

Some people may experience problems with their heel bone, the calcaneus. This may be either a fracture or fluid within the bone. People with problems with their heel pain may experience pain that builds with activity, a constant deep dull ache, or pain during the night.