Plantar fasciopathy (formerly “plantar fasciitis”) is quite a common condition and I see this in the clinic more frequently than I previously used to. It's hard to say whether it is diagnosed more accurately these days, or its incidence is actually increasing!
Essentially the fascia of the plantar surface (under side) of the foot becomes painful, commonly at the calcaneal (heel bone) insertion, or the arch of the foot.
Usually it involves morning pain where it can be almost impossible to bear weight for 5-30mins, and pain with walking longer periods or on harder surfaces.
The wider literature supports the following risk factors in developing plantar fasciopathy:
High BMI (or just body mass)
Heavier people generally place greater compressive and tensile loads through the plantar muscles and fascia with each step. Their everyday loads can be quite high, and therefore only small increases in activity levels can result in large increases in foot loading pressure (van Leeuwen, 2016).
High loading rate (relatively fast increase in loading)
This is essentially when someone increases their body weight or increases their activity levels significantly and quickly. Essentially it is "unaccustomed activity". Examples are during some pregnancies, novice runners (especially if they have just decided to “get fit” without a structured approach), and heavy scheduling of sporting commitments (too many events in a short space of time) (Rathleff, 2015). Physiotherapy treatment and education is invaluable here.
Specific foot muscle weakness
Specific intrinsic muscles of the foot are responsible for attenuating forces sustained during various types of physical activity including walking. They help keep the shape of the foot’s arch. Weakness of these foot muscles contribute to poor force attenuation and the development of plantar fasciopathy (Huffer, 2017). Strengthening these muscles is important to a successful outcome, and reducing risk of recurrence (or prevention).
Being aware of the above will help to prevent plantar fasciopathy.