Heel spurs
Heel spurs are irregular outgrowths of bone of up to one and a half centimetres extending from the heel bone into tendon (typically in the flexor digitorum brevis, quadratus plantae and abductor hallucis muscle insertions) or ligament (plantar fascia).
Many are too small to be picked up on x-rays. Most spurs do not cause symptoms. The larger the spur the more likely they will be painful, often leading to gait and posture disorders, which can further exacerbate the condition.
Usually, the onset of pain in the heel is gradual and can be intermittent or chronic. The pain is frequently described as like a knife or pin sticking into the bottom of the foot, especially when taking the first steps in the morning when getting out of bed or after sitting for a prolonged period of time, and is often accompanied by limping.
Typically, the sharp heel pain eases after a few paces but intensifies by day's end if weight bearing for a long time or at the end of a long walk, or when jogging or running.
Although they are occasionally found in young adults, (especially running and jumping athletes), heel spurs most occur in older adults reaching a peak incidence around sixty years of age. Although many people who have plantar fasciitis also have bone spurs, not all people with bone spurs have plantar fasciitis because there are a number of different causes.
Heel spurs develop over a period of many months or years often as a result of a combination of repeated excessive tension strain on foot, tension and compression of the plantar fascia, and compression on the heel bone. That’s why they occur more in people who are older, over-weight and who have osteoarthritis in their hips and/or knees. Achilles tendon spurs are also much more common in those with heel spurs because the calf muscles, the muscles of the feet and the plantar fascia often all work together.
Spurs may be an adaptive response to heel bone stress fractures or to excessive tension/compression by giving the bone a greater surface area and so greater protection from the excessive forces acting on it. Small spurs can also develop as part of normal bone development.