Plantar Aponeurosis Overview
Plantar aponeurosis injury dampens the spirits of all of its victims; from the most elite of athletes to those with sedentary lifestyles and everyone that can be categorized in between. Sportsmen of note who have suffered from plantar aponeurosis injury include AFL stars Robert Harvey, Brad Ottens and Josh Kennedy – of which two have explored some pretty extreme interventions to free them of the pain and get back to the game they love, which will be discussed in our up-coming and first well known athlete interview to be release in the coming days. Before we release that interview however, let’s get an overview of what the plantar aponeurosis is, what the recommended treatment is and the possible differential diagnosis which may be relative to the area.
The plantar aponeurosis or plantar fascia as it is more colloquially known is a flat sheet of thickened, poorly vascularised and poorly innovated, deep fibrous connective tissue of the foot which can measure between 2.2 and 5.4milimetres (Cardina, Chhem, Beauregard, Aubin, & Pelletier, 1996). The broad white longitudinal fibres originated at the medial tuberosity of the calcaneus and insert at the proximal head of the phalanges. Anteriorly, at the metatarsal-phalangeal joints latitudinal connective tissue fibres reinforce the supportive nature of the plantar aponeurosis creating the Transverse Arch of the foot. Similarly, a medial and lateral longitudinal band of connective tissue further support the respective arches while protecting deeper structures of the foot (Brukner, 2013).In younger people the plantar aponeurosis can be intertwined with the achillies tendon which can make diagnosis of some presentations difficult.
The plantar aponeurosis is able to support up to twenty-five percent of the load experienced by the medial longitudinal arch. During dynamic gait the plantar aponeurosis may only elongate up to two percent of its relaxed size however, the stretch tension and isometric contraction which occurs in association with the windlass mechanism acts like a spring moment during propulsion. The windlass mechanism occurs when the first phalangeal dorsiflexes and the metatarsal plantarflexes – stretching the plantar aponeurosis and lifting the medial longitudinal arch height through shortening the distance between the bones of the foot (Michaud, 2011).
Allied Health Professionals regularly see heel pain in patients and very often it is quickly diagnosed as plantar fasciitis or plantar fasciosis without the use of imaging or a sound clinical reasoning for the condition. Many issues arising at the heel have quite similar signs and symptoms and as a result can be misdiagnosed or treated incorrectly.
Common heel pain signs and symptoms may include; localized pain, pain on palpation of the heel, pain with the first steps after rest, tight calves and the occurrence of a sudden impact onset or insidious onset. Differential Diagnosis for heel pain presentation is shown in the table below in addition to possible treatment regime that may be implemented.
| Condition | Diagnostic Tools/Differences | Treatments |
| Fat Pad Contusion | -Pain does not ease with activity -XR shoes nil signs of spur -US shows nil signs of increased plantar fascia thickness – Sudden impact |
Icing nightly or when sore
Heat/anti-inflammatory medications or topical creams for prevention of pain Off-loading of the heel through orthotic devices or poron buttons |
| Calcaneal Fracture/ Stress Reaction | -Pain does not ease with activity – XR shows sign of fracture – CT scan shows signs of stress reaction |
Off-loading devices including strapping, orthotic devices or orthopaedic boots. Modified activityweight bearing exercises as soon as achievable |
| Heel Spur | -Pain may or may not ease with activity
– XR shows increase in bone uptake at calcaneal |
– Rolling of frozen water bottle daily or when ever sore
– Off-loading of area through taping or orthotic devices including poron buttons – Self massage through calves and plantar surface of the foot inclusive of foam rolling and spiky ball. -Stretching of calves and plantar muscles – Isometric strengthening activities – Footwear changes can be appropriate |
| Plantar Fasciitis/ Fasciosis | – Initially improves with activity – US shows increased plantar fascial thickness – US shows signs of increased inflammation |
|
| Plantar Neuritis | – Pain is superior-medial of the calcaneal tuberosity – May be tingling and numbness involved due to nerve irritation |
Evidence Regarding Treatment
It was found in a prospective randomized study conducted by (DiGiovanni, Nawoczenski, lintal, Murray, Wilding, & Baumhauer, 2003)that tissue specific plantar fascia stretching showed significantly better results when compared to a generalized calves and achillies tendon based stretching regime. Most notable were the decreases in worst pain measured via VAS score with a p-value = 0.02 and first step function and pain with a p-value =0.006. From these results it can be inferred that the use of non-weight bearing stretching exercises specific to the plantar aspect of the foot creates greater pain reduction than a standard weight-bearing achillies tendon stretching program.
Chew, Leong, Lin, Lim and Tan established in a 2013 randomized trial that both plasma injection and extracorporeal shockwave therapy combined with conventional treatment created more improved outcomes for patient pain and function when compared with conventional treatment as a standalone. However no significant difference was found between ESWT and plasma injection (Chew, Leong, Lin, Lim, & Tan, 2013).
In a 2014 randomized control study by (Suleymanoglu, Esmaeilzadeh, Sen, Diracoglu, Yaliman, & Eskiyurt, 2014)comparing radial shock wave therapy and low level laser therapy for chronic plantar fasciitis it was concluded that both RSWT and LLLT were significantly effective in the decrease of thickened plantar fascia immediately after the 3-month assessment p<0.001. The specific modalities mentioned here are not included in the above table due to practitioner cost, invasive nature and the point that this measure was used after a 6 months non response period to conservative interventions.
When comparing full-length silicone insoles versus ultrasound-guided corticosteroid injection for the management of plantar fasciitis through means of randomized clinical trials, it was found that after one month of treatment both groups had significant improvement of both pain and function related to their foot pain, however those involved in the injection group were found to have statistically significant differences (p<0.005) in VAS, ultra-sonographic thickness of plantar fascia, foot and ankle outcome score for daily living activities and sport and recreation function. However, conclusively it was advised that silicone insoles were used as a first line treatment given the minimally non-invasive nature (Yucel, et al., 2013).
A randomized controlled trial of calcaneal taping, sham taping and plantar fascia stretching in 2006 found a significant difference between calcaneal taping and stretching of the plantar fascia/ sham taping/control in the category of VAS pain (p<0.006) , (p<0.001) and (p<0.001) respectively. Stretching was found to have statistical significance over the control group (p=0.026). It was concluded that calcaneal taping was shown to be more effective as an intervention for plantar heel pain (Hyland, Webber- Gaffney, Cohen, & Lichtman, 2006).
In the event of kinesiology taping for the short term treatment of plantar fasciitis it was found that no significant difference was seen in the either group using kinesiology taping with traditional physical therapy or just traditional physical therapy (Tsai, Chang, & Lee, 2010).
When exploring more invasive treatments plantar fasciotomy with the use of endoscopic or radiofrequency lesioning techniques have been found to be around 70-90% effective, however with any surgical intervention comes risk, in this case both flattening of the medial longitudinal arch and heel hypoesthesia (Davies, Weiss, & Saxby, 1999).
In conclusion it can be seen and so it should be with any presenting complaint that full and comprehensive assessment be complete to best support any clinical reasoning and diagnosis of a specific condition. Furthermore, a holistic approach to treatment is required to ensure an adequate and speedy rehabilitation from plantar foot pain associate with the plantar aponeurosis. Using the highest evidence based interventions in combination appears to provide best outcomes for these conditions.
In our next post we will be discussing plantar fascial injury with two times Brownlow Medallist Robert Harvey as well as diving into his unconventional approach to treating said pain with a brutal home remedy
Jackson McCosker
Director /Chief Editor
FootNotes Publishing 