Acute plantar fasciitis is an overuse syndrome that usually responds quite well with conservative treatment.2, 4, 13, 25, 26, 27, 28, 29, 30
It is an overuse syndrome whereby the repair process cannot keep up with the stress that the body endures. The three major sources of stress are poor training technique, repetitive overuse and inherent biomechanical imbalances.3
Large increments in training demands without enough time for recovery can initiate an inflammatory process especially in areas with biomechanical abnormalities. The repetitive sprints and jogging activity sustained during soccer can cause additional aggravation to the inflamed condition. The patient’s pes planus with mild heel eversion and overpronation contributed to added tensile stresses on the plantar fascia. Chronic cases of plantar fasciitis present additional variables that can be addressed with the integration of various therapeutic interventions. This case study demonstrated that the combined use of acetic acid iontophoresis, physical therapy modalities, athletic taping, soft tissue therapy, joint mobilization / manipulation, stretch / strengthening exercises and proprioceptive facilitation and orthotics helped this patient return to her regular activities within a period of six weeks.
Treatment using acetic acid iontophoresis had been previously indicated in treating conditions such as myositis ossificans, calcific bursitis and calcific tendonitis. The rationale for treatment would primarily aim at increasing the solubility of calcium deposits in tendons and soft tissues22, 31
to encourage the removal of excess calcium ions from the injury site into the blood stream. With respect to pain generation, current literature focuses beyond radiographic evidence of pathological calcified or ossified structures and places a greater emphasis on the physiological events that precedes this process. Histopathologic changes of patients who have chronic heel pain include an initial low-grade periosteal inflammation, edema, fibroblastic and inflammatory cell proliferation.22
Calcium deposits infiltrate inflamed, dead, or dying tissue despite normal blood calcium levels and normal calcium metabolism.32
One theory proposes that denatured proteins from damaged cells unmask reactive groups that bind with phosphate radicals that attract and bond with calcium ions, which in turn, open collagen bundles causing tissue swelling, fat saponification and further tissue disruption.22
Consequently, these calcium ions break protein cross-linkages with polyaminoglycans like chondroitin sulfate disrupting other protein linkages.33
The continual progression of chronic tissue inflammation due to abnormal stress progresses from a physiological reaction to fibrocartilagenous tissue formation leading to cartilage deposition and eventual bone spur development.22
Shama and Kominsky noted that of 1,000 patients who had been radiographed, only 132 had evident heel spurs of which, only 39% complained of a history of heel pain.22
Thus, it could be reasoned that bone spurs are the long-term pathological response to maladaptive tissue dysfunction and that the deposition of dystrophic calcium that occurs prior to osseous formation is the primary focus of chronic pain generation. Japour et al. describes in detail the theoretical biochemical process where the use of acetic acid iontophoresis converts insoluble calcium carbonate in chronically inflamed tissue to calcium acetate, which is blood-soluble.22
Pulsed ultrasound was used to reduce inflammation, perfuse local blood flow and facilitate the removal of the newly formed calcium acetate into the blood and thereby remove it from the localized area of heel pain.
The use of athletic taping provided temporary mechanical stability and support for the strained plantar fascia.31, 34
The amount of actual mechanical support has been questionable and current literature places a greater emphasis on proprioceptive mechanisms via sensory afferent cues through traction of the tape on the skin to reduce pain intensity and increase muscular and joint support.35
Nonetheless, athletic taping and or bracing are effective means to limit range of motion, increase proprioception and reduce pain intensity to injured structures.36, 37
Studies have shown that athletic taping was superior to anti-inflammatories and heel cup treatments1
or NSAIDs in combination with injections.15
Athletic taping using non-elastic zinc oxide tape to the plantar fascial arch as described in Arhheim was initially used to reduce strain and pain intensity on the plantar fascia.24
In addition, prophylactic bilateral plantar arch fascial taping was utilized before practices and games to encourage a progressive return to soccer activity and limit the aggravation of symptoms. Once the patient had adapted to the new orthotics, the athletic taping was omitted from treatment to evaluate her progressive response.
Ample evidence exists, based on subjective pain relief, symptom resolution and patient satisfaction, to support the continued use of orthotics in treating biomechanical injures in the lower limb, particularly in runners.25, 27, 28
Orthotic intervention is appropriate for those injuries resulting from identifiable abnormal biomechanics such as hyperpronation, excessive rearfoot eversion, high eversion velocity, increase internal rotation, increased impact and loading rate of vertical ground reaction force, excessive supination with increased ankle inversion movements and external rotation moments.28, 38
In addition, orthotics may also derive their benefit by altering muscle activation and proprioceptive mechanisms involved in regulating muscle function and dampening soft-tissue vibrations.28
For plantar fasciitis with associated pes planus, Nawoczenski et al. prescribes a firmer, more rigid orthotic with a medial heel post to help minimize excessive pronation.28
Gross et al. suggests that the custom semi-rigid foot orthotics may maintain medial longitudinal arch height sufficiently to reduce tensile stress within the plantar fascia and provide clinically significant reductions in pain and disability.27
The custom orthotics may incorporate a viscoelastic polymer-filled heel cushion at the medial calcaneal tubercle for additional pressure relief.28
In addition, straight-last footwear with motion control features such as reinforced heel counter and medial midsole reinforcement should be recommended for this foot type.28
In prescribing orthotics, the age, weight, foot type, biomechanical characteristics and activity level should be considered to determine the degree of rigidity and accessory modifications necessary to limit excessive movements of the lower limb complex. This 145 pound patient with forefoot overpronation was initially given a very rigid 3mm thick orthotic with a neutral heel post. Over the course of one year, this orthotic was not successful in significantly reducing her symptoms and led to the development of additional problems in the knee, quadriceps and lateral pelvic musculature. Through clinical experience, it was determined that a 2 mm thick orthotic with a 2-degree extrinsic medial heel post and additional heel cushion was appropriate for her weight level and biomechanical foot dysfunction. This orthotic would be able to provide enough support for the longitudinal arch and limit overpronation and rearfoot eversion. Accommodation to the new orthotic took two weeks with a progressive reduction in lower limb pain and an increased ability to sustain longer running and playing times.
Several manual therapeutic techniques were used to manipulate soft tissue and joint structures to restore normal muscle lengths and joint movements. Initial treatments focused on the plantar fascia and gastrocnemius/ soleus complex to reduce tension and muscle hypertonicity. Manipulation and mobilization of the ankle mortise, subtalar and tarsal-metatarsal joints as well as axial traction were performed in the presence of restricted motion. Deeper myofascial treatments focused on the anterior and lateral leg compartment and the TFL/IT band complex. Brantingham et al. describes the benefits of soft tissue therapy on the plantar muscles and fascia in addition to joint manipulation to restore normal myofascial movement.17
Cross-frictional massage was used to soften and reduce fibrotic scar tissue17
in the plantar muscles and fascia followed by ice massage during the late phases of recovery.
The prescribed stretches were advised to be done twice per day for 20 seconds and included stretches for the gastrocnemius, soleus, fibularis, TFL and IT band, quadriceps, hamstring and iliopsoas muscles. Once the pain intensity reduced, non-weight-bearing stretching of the plantar fascia as described in DiGiovanni et al. was included in the daily routine.39
Towel scrunches and foot scoop exercises were used to facilitate the intrinsic muscles of the foot and reduce plantar fascial tension. Foot inversion/eversion and ankle dorsi/plantar flexion strengthening exercises targeting the extrinsic muscles of the lower leg progressed using increasingly resistive Theraband tubing to reduce muscular imbalance and increase mechanical stability. These exercises were performed every other day and progressed from 2 sets of 15–20 repetitions to 3 sets over a 4 week period. During the 3rd–6th week, a wall pulley machine was used to perform the same exercises within the clinic. VMO facilitation, weighted knee extension and flexion exercises using a weight ratio of 1.3 to 1 ratio was used to target the quadriceps and hamstring muscle groups. Strength progression was monitored utilizing the Zinovieff weightlifting protocol. Closed chain modified lunges and wall squats were used to facilitate compound muscle groups and functional movement patterns. Modified jogging was initiated during this phase of recovery and progressed from running 5km to 10 km with 1 km intervals over a period of 2 weeks.
Proprioceptive exercises were used to facilitate intrinsic and extrinsic muscles to enhance motor coordination, strength and stability thereby reducing tensile stress on the plantar fascia. Balance exercise improves proprioception during both the rehabilitation phase and the competition phase of recovery.40, 41
The proprioceptive exercises progressed from 1-leg standing with eyes open to eyes closed; standing wobble board exercises to 1 leg stance wobble board exercises with leg bends.