Current Pedorthics | March-April 2013 | Vol. 45, Issue 2 | Page 18

DIFFERENTIAL DIAGNOSIS OF HEEL PAIN may also be lessened by shoe gear, such as Skechers or MBT, because the built- in rocker bottom present in these shoes limits the range and speed of digital dorsiflexion. In addition to strengthening the digital flexors, chronic plantar fasciitis often responds well to low-dye taping and to custom and prefabricated orthotics Fig. 2. Plantar fascia (which are equally effective for home stretch. This the short-term treatment of plantar stretch is held for 10 fasciitis [3]). As demonstrated by seconds and repeated Kogler et al. (4,5), buttressing 30 times per day. The the plantar fascia should medial longitudinal arch and be lightly massaged incorporating rearfoot varus and/or while performing this forefoot valgus posts may significantly stretch. lessen tensile strains present in the plantar fascia. Other conservative treatment interventions include frequent stretching of the posterior calf musculature and the use of night braces. DiGiovanni et al. (6) demonstrate improved clinical outcomes occur with the simple addition of the home stretch illustrated in figure 2. This stretch is held for 10 seconds and repeated 30 times per day. Although deep tissue massage may be helpful because it improves resiliency of the plantar fascia and may stimulate repair, care must be taken to avoid irritating the medial and lateral plantar nerves, which may be contused by overly aggressive cross-friction massage. When performed properly, deep tissue massage coupled with stretches to restore first metatarsophalangeal joint dorsiflexion almost always results in a 10° increase in the range of hallux dorsiflexion. This is significant, since surgical release of the medial band of the plantar fascia has been shown to increase Fig. 3. Baxter’s neuropathy test. When the nerve to abductor digiti quinti is compressed, the patient is unable to abduct the fifth toe (A). MPN=medial plantar nerve; LPN=lateral plantar nerve; BN=Baxter’s nerve. 16 Pedorthic Footcare Association www.pedorthics.org the range of first metatarsophalangeal joint dorsiflexion by 10° (7). Because of this, surgical release of the plantar fascia (which may result in a gradual destruction of the medial arch) should not be considered unless manual therapy fails to improve the range of first metatarsophalangeal joint dorsiflexion. The response to manual therapy can be evaluated with careful pre- and post-treatment measurements of hallux dorsiflexion. The efficacy of manual therapies for lessening plantar heel pain was proven in a randomized controlled trial in which the addition of trigger point massage to a conventional self-stretching protocol produced superior short-term outcomes compared to stretching alone (8). Alternate causes of heel pain include enthesopathy from various autoimmune disorders, Baxter’s neuropathy, calcaneal stress fracture, and/or heel spur syndrome. The autoimmune disorders, such as rheumatoid and psoriatic arthritis, frequently produce pain and swelling at the plantar fascia origin, and are often misdiagnosed because the early signs are similar to those associated with mechanical plantar fasciitis. Clinical clues suggesting autoimmune causes for heel pain are that these disorders tend to produce discomfort bilaterally, and the swelling tends to be more extreme. If psoriatic arthritis is the cause, skin plaques can often be seen on the hands or behind the ears. Suspected cases should be referred to a rheumatologist. Another cause of heel pain is Baxter’s neuropathy. This condition represents a nerve entrapment syndrome in which the nerve to abductor digiti quinti (also known as Baxter’s nerve) becomes inflamed beneath the proximal portion of the plantar fascia. Clinical signs of Baxter’s neuropathy include the reproduction of pain by abducting and dorsiflexing the forefoot for 30-60 seconds, a positive tourniquet test (i.e., pain is reproduced by inflating a blood pressure cuff placed around the lower leg to slightly above systolic pressure for 30 seconds) and/ Fig. 4. Nerve glide technique. To mobilize Baxter’s nerve, the patient places the heel on an elevated platform and then alternately extends the neck while dorsiflexing the ankle and toes (A), and then flexes the neck while plantarflexing the involved ankle and toes (B). Each cycle is performed for approximately 5 seconds and there should be minimal discomfort while performing this procedure.