Analysis of Pressure Pain Hypersensitivity, Ultrasound Image, and Quality of Life in Patients with Chronic Plantar Pain: A Preliminary Study

Objectives. To evaluate widespread pressure pain in patients with chronic plantar heel pain compared with that in healthy controls and to investigate the differences in ultrasound imaging and quality of life between these two groups. Methods. A total of 22 patients (11 female) with chronic plantar heel pain and the same number of healthy patients, matched according to age and gender, were included in this pilot study. Pressure pain thresholds (PPTs) were bilaterally assessed over the calcaneus bone, the plantar fascia, the first and fifth metatarsals, the soleus muscle, the second metacarpal, and the zygapophyseal joint of C5-C6. Plantar fascia thickness was measured via ultrasound imaging. In addition, quality of life and physical function were assessed using the Short-Form 36 (SF-36) questionnaire and the Foot and Ankle Ability Measure (FAAM) questionnaire, respectively. Results. Analysis of covariance (ANCOVA) results showed significant differences in the PPTs at all points between the groups (P < 0.001), but not between sides. The PPTs were significantly lower in the patients than in the controls at all sites (P < 0.05). The results showed significant increases in fascia thickness at the calcaneus insertion (group: F = 74.172, P a parts per thousand currency signaEuro parts per thousand 0.001; side: F = 8.920, P a parts per thousand currency signaEuro parts per thousand 0.001) and the middle fascia point (group: F = 133.685, P = < 0.001; side: F = 11.414, P = < 0.001) on ultrasound in the patient group compared with the matched control group. The analysis also revealed that the patient group had a significantly lower score on every subscale of the SF-36 and FAAM questionnaires (all P < 0.001), except for the mental component, compared with the matched control group. Discussion. Patients suffering from chronic plantar heel pain showed widespread and bilateral hypersensitivity, increased thickness of the plantar fascia in the affected foot, and deterioration in quality of life and physical functioning compared with matched controls.