Changes in Rearfoot Alignment in Chronic Plantar Heel Pain

"Antero-medial load shift" in unilateral plantar heel pain - A cross-sectional exploratory study

BACKGROUND AND PURPOSE

Plantar foot pressure provides an insightful data in the ankle and foot complex which may aid in the detection of underlying pathology. Since individuals with unilateral plantar heel pain (PHP) tend to develop compensatory loading strategies, this study aimed to observe the foot loading pattern compared to the asymptomatic side and its relationship with the morphological variations in individuals with unilateral PHP.

METHODS

It was a prospective cross-sectional study done on 17 participants with unilateral PHP. The calcaneal inclination and calcaneal first metatarsal angles were measured using lateral weight-bearing radiographs for both symptomatic and asymptomatic feet. Static and dynamic plantar foot pressures for both sides were obtained using a "Portable baropodometry platform 0, 5 m Entry Level footscan®.

RESULTS

On the symptomatic side, the pressure in the lateral heel was reduced by 65% in static and 67% in dynamic measurements, while in the medial heel, it was reduced by 16 % in static and 47 % in dynamic measurements compared to that of the asymptomatic side. There was a transfer of pressure from the hind foot to the forefoot by 44 % in static and 46 % in dynamic measurements resulting in anterior load shift. It was also observed that the prevalence of PHP was higher in the normal arched foot (59%).

CONCLUSION

Based on the observations, compared to the asymptomatic side, patients with unilateral plantar heel pain exhibited an anteromedial load shift (AMLS) in their plantar pressures. PHP was reported higher in the foot with normal morphology.

LEVEL OF EVIDENCE

Level 4.

Can we predict which patients with plantar heel pain are more likely to benefit from insoles? A secondary exploratory analysis of a randomized controlled trial

Background

Plantar heel pain (PHP) is a common cause of foot complaints, for which treatment with custom-made insoles is frequently applied. So far few studies have investigated patient characteristics that predict response to these treatments. The aim of this secondary exploratory analysis was twofold; firstly, to identify patient characteristics that predict prognosis in patients with PHP treated with insoles, and secondly to identify characteristics that might interact with treatment with insoles.

Methods

Data from a randomized trial in which participants received either custom insoles (N = 70) or sham insoles (N = 69) were used. At baseline, information was collected on demographics, foot symptoms, foot and ankle range of motion, navicular drop, presence of neuropathic pain, physical activity and other illnesses in the last 12 months. The primary outcome of this study was the Foot Function Index score (FFI) at 26 weeks. Multivariable linear regression models were generated to identify patients characteristics that predict the outcome for each type of intervention (i.e. insoles and GP-led usual care).

Results

We found two variables associated with a better function score at 26 weeks in patients treated with insoles, female sex (β − 9.59 95%CI -17.87; − 1.31) and a lower FFI score at baseline (β 0.56 95%CI 0.30; 0.82). Explorative analyses in patients treated with insoles showed no significant interaction effects between the type of insole (custom-made versus sham) and any of the potential predictive factors.

Conclusion

When communicating about the effect of insoles for PHP clinicians should take sex and the amount of pain and disability at first presentation into account. Women and people with better foot function scores at baseline (according to FFI) might respond better to treatment with insoles in terms of foot function.

Trial registration

Trial registration: NTR5346.