Scourge of the young and older, the runners and the weekend warriors.
Nobody likes to be off their feet so to speak. If there is one thing that really gets my back up as a physio is when patients tell me that they have been told “there’s nothing that can be done for it” when talking about an injury they have.
True plantar fascia is not the fastest resolving kid on the block when it comes to responding to treatment but that doesn’t mean its a hopeless situation. Lets get rid of the myths and deal with the facts shall we?
What is the plantar fascia ?
Plantar fascia (Warning Ignore spurs and microtears )
The plantar fascia is a fibrous structure that extends from the medial part of the heel and attaches to the capsule of the joints of your toes, the metacarpal phalangeal joints.
It can be considered as part of the tendon family.
Its mainly composed of the protein type 1 collagen which is arranged along the length of the plantar fascia. Not surprisingly it has a large population of nerve endings and receptors in it, (anyone with ticklish feet can attest to that!), and interestingly it has significant muscular attachments to the intrinsic muscles in the foot.
Studies have also shown that in younger individuals there appears to be a very definite blending of the plantar fascia with the paratendon component of the achilles tendon. As we get older this relationship seems to be less as the tendon starts to become more bony in its structure.
There is an extensive nerve supply of the foot and a nerve named baxter.
As well as the strong collagen structure of the plantar fascia there is an extensive nervous innervation of the foot.
A potential cause of plantar foot pain that can easily mimic symptoms of plantar fasciitis is compression of the inferior calcaneal nerve (ICN) under the arch of the foot. The ICN is a branch of the lateral plantar nerve on the bottom surface of the foot. The nerve is also sometimes called Baxter’s nerve. It is thought that this nerve can get irritated or compressed between the muscles and bones of the foot causing pain.
(I had a dog called Baxter who got on my nerves, the glorious idiot)
The plantar fascia’s function in walking and running.
The main function that people attribute to this structure is related to the windlass effect. This is where the the structure quickly tightens up and locks in the small bones of the foot, essentially turning a highly mobile foot into a rigid structure to help move us forwards. This occurs as we go from foot flat on the floor to pushing off our big toe.
Lesser understood role in the function of the foot, shock absorption and position sense.
Considering the intimate connection with the achillies tendon via the paratendon as well as the high content of type 1 collagen and elastin it should be of no surprise that it is an important shock absorber, storer of energy and “spring”, much like the achillies tendon.
In all probability it demonstrates these structures are not distinct entities but part of a energy absorbing and releasing complex. It’s not too far a leap then to surmise that as the relationship between the achillies and the plantar fascia reduces as we get older that this is a potential factor in the development of achillies or plantar fascia problems.
The blending of the plantar fascia with the small muscles of the foot also add to its role in fine movement function and joint position sense. If the structure is painful then these functions of the foot are more than likely also affected.
It’s not just a sore heel.
Its a multifactorial issue and is very dependent on the individual as to what is the best way to treat it and how it responds.
Age, activity levels, foot mechanics and symptom presentation will all have a role in planning the management and achieving the best outcome.
What are the symptoms of plantar fasciopathy ?
The following are usually symptoms associated with plantar fascia;
- Symptoms that feel like a stone bruise.
- Pain with weight bearing, walking or running.
- Pain at the base of the heel.
- Pain in the inside border at the sole of the foot.
- Stiffness on getting up that eases as you walk more.
Differential Diagnosis and plantar fascia pain;
If pain is more persistent and doesn’t ease with rest it may be a more chronic sensitised form of plantar fasciopathy . However the following conditions may be presentations that can mimic plantar fascia or are co – existing;
- Irritation of the inferior calcaneal nerve / Baxter’s nerve.
- Periosteal irritation / bruising. This is the skin like covering of the bone that is highly sensitive.
- Heel spur fracture.
- Fracture of the calcaneous.
Want to know more about plantar Fascia issues? You can download the Arana Hills physiotherapy and dynamic podiatry info book here:
Alternatively book in to see one of us to get you back on your feet.