Plantar fasciitis is one of the most common causes of heel pain affecting 3.6% to 7% of the population (Hill et al, 2008) and accounts for 8% of all running-related injuries (Malliaris et al, 2013). Plantar fasciitis affects both sedentary and athletic people and is thought to result from chronic overload caused by either lifestyle factors or exercise (Dyck & O’Neill, 2004).
The Pathophysiology of Plantar Fasciitis:
The plantar fascia is a thick band of fibrous tissue which originates at the medial calcaneal tubercle and helps to support the arch of the foot. Repetitive tensile overload from activities such as long periods of standing or running can cause changes within the aponeurosis which can lead to the development of plantar fasciitis. Plantar fasciitis is considered to be a degenerative rather than an inflammatory condition (Thomas et al, 2010; Shwartz, 2014)). Histopathologic studies indicate that plantar fasciitis is in fact similar to degenerative tendinosis. In plantar fasciitis, degenerative changes occur at the plantar fascia enthesis, including a deterioration of collagen ﬁbres and structure and increased secretion of ground substance proteins. Focal areas of ﬁbroblast proliferation also develop together with increased vascularity (Jarde et al, 2003; Lemont et al, 2003).
Signs and Symptoms:
The most obvious sign of plantar fasciitis is intense heel pain localised primarily where the plantar fascia attaches to the anterior calcaneus or heel bone. Typically, any heel pain will feel much worse on first waking in the morning or after a long period of rest such as sitting. However, it can also occur via weight bearing activity such as a long walk or a long period of standing. Typically, in athletes, pain can arise after a long period of training. Pain can often wear off a little when warming up but will then reappear at the end of a training session. Stiffness in the foot can also be present (Petraglia et al, 2017).
A variety of both intrinsic and extrinsic risk factors can contribute to the development of plantar fasciitis.
Intrinsic Risk Factors:
- Pes planus (flat feet)
- Pes cavus (high-arched feet)
- Shortened Achilles tendon
- Over-pronation (inward roll)
- Limited ankle dorsiflexion
- Weak intrinsic muscles of the foot
- Weak plantar flexor muscles
Extrinsic risk factors:
- Poor biomechanics or alignment
- Hard surface
- Walking barefoot
- Prolonged weight bearing
- Inadequate stretching
- Poor footwear
(Young et al, 2010)
On assessment, the following factors can often be identified:
- Pain on palpation of the proximal insertion of the plantar fascia.
- A positive Windlass test. This helps to evaluate plantar fascia loading.
- Negative tarsal tunnel tests (dorsiflexion/eversion test).
- Limited active and passive talocrural joint dorsiflexion range of motion.
- An abnormal standing foot posture, as assessed using the Foot Posture Index Score.
- High body mass index in nonathletic individuals.
(Petraglia et al, 2017)
Imaging is typically not necessary for the diagnosis of plantar fasciitis but may be helpful if there are other likely reasons for heel pain. The condition can be differentially diagnosed from many other conditions.
- Tarsal tunnel syndrome: posterior tibial nerve impingement. This can cause a burning sensation in the plantar region worsened by dorsiflexion.
- Neuropathy such as from diabetes. This can cause paraesthesia in the plantar region.
- Acute calcaneal fracture. This can occur after landing heavily on your heel.
- Calcaneal stress fracture. This is more commonly seen in runners.
- Severs disease: calcaneal apophysitis. This can be seen in paediatric patients with open physes.
- Systemic arthritides such as rheumatoid . Here you would expect pain to occur in multiple joints along with heel pain.
- Fat pad atrophy. This is more common in elderly people.
- Fat pad contusion. This is more likely associated with a hard landing onto the heel.
- Achilles tendinopathy. This normally elicits posterior calcaneal tenderness and tendon pain.
- Retrocalcaneal bursitis. Pain can be palpated in the retrocalcaneal bursa.
- Posterior tibial tendinopathy. This gives rise to pain along the posterior tibial tendon and at its insertion onto the mid foot arch.
(Goff & Crawford, 2011)
A large number of different conditions can lead to heel and foot pain. With plantar fasciitis, the vast majority of people will get better but knowing what to do and how to treat it is important in order to get rid of what can be a painful and frustrating condition. Now that we’ve discussed what it is and how to diagnose it, we’ll be talking about treatment options for plantar fasciitis in our next blog: How to Treat Plantar Fasciitis. This will give you a good idea of what works and what doesn’t in order to get better.