Background: Non-operative treatment for plantar fasciitis varies widely and includes the use of night ankle-foot orthoses (AFO’s). Some studies have shown that this is more effective in the initial management of plantar fasciitis than anti-inflammatory therapy. During sleep the foot and ankle tend to assume a plantarflexed position, which results in tightness of the calf muscle group, accounting for the stiffness and pain experienced by patients as they take their first weight bearing steps in the morning. However, when the foot and ankle are kept in a dorsiflexed stretched position at night, stress relaxation occurs and the plantar fascia relaxes.
Aim: Compliance with night AFO’s that dorsiflex the foot/ankle has always been a problem. This study compares the effectiveness of a posterior AFO, which dorsiflexes the foot, with an anterior AFO, which maintains the foot in plantigrade, asking whether it is absolutely necessary to dorsiflex the foot and ankle during the night to avoid early morning pain and stiffness, or whether it is it sufficient just to maintain the foot in plantigrade.
Methods: 18 participants were recruited on a voluntary basis and at random from among those patients referred to the Orthotics department with plantar fasciitis to be provided with a night orthosis. The inclusion criterion was that the diagnosis was purely plantar fasciitis with no secondary diagnosis, symptoms or complications. Each participant was given a questionnaire to fill in; this evaluated how satisfied the participants were with the orthosis with regards to comfort, ease of use and appearance, and whether the pain in the foot was reduced and at what stage was it reduced. The two types of AFO’s used in this study were:
A posterior AFO that holds the foot in dorsiflexion. The amount of dorsiflexion could be adjusted.
An anterior AFO that keeps the ankle and foot in plantigrade, with no adjustment to the amount of dorsiflexion.
Results: 67% of the participants confirmed that morning pain and stiffness was less after wearing the AFO; this included 78% of those that wore the anterior AFO and 56% of those that used the posterior orthosis. 56% of all participants reported that the orthoses were uncomfortable and disrupted sleep. The most uncomfortable was the posterior AFO (89%), as opposed to the anterior one (22%). Both types of orthoses were reported to be relatively easy to don and doff (89% anterior AFO and 78% posterior AFO). On a scale of 1 to 10, the participants were asked to grade the pain before starting the orthosis treatment regime, after 6 weeks of wearing the AFO and again 6 weeks later. On average, the anterior AFO reduced the pain from 7 to 2.1, while the posterior orthosis only reduced the pain from 8.1 to 6.7.
Conclusion: In general, plantar fasciitis night AFO’s are poorly tolerated orthoses, however, their use can be justified in that the pain levels are reduced. The anterior AFO seems to be more effective in achieving this, without dorsiflexing the foot/ankle beyond plantigrade. Thus, one could argue that there is no need to dorsiflex to achieve the goal. However, further investigation is necessary with a larger patient cohort.
