The evalaution of the foot core system in individuals with plantar heel pain

Objective: To compare foot posture, plantar sensation, plantar fascia thickness, intrinsic foot muscle performance, and abductor hallucis morphology in individuals with and without plantar heel pain (PHP). Design: Cross-Sectional. Setting: Laboratory. Participants: Sixteen individuals with PHP and sixteen matched healthy participants. Main outcome measures: Static foot posture, plantar sensation, plantar fascia thickness, intrinsic foot muscle performance and abductor hallucis morphology were evaluated. Foot posture was assessed with the Foot Posture Index-6. Abductor hallucis morphology and plantar fascia thickness were measured utilizing diagnostic ultrasound. Plantar foot sensation was assessed at the head of the first metatarsal and medial longitudinal arch using Semmes-Weinstein Monofilaments. Intrinsic foot muscle performance was assessed using the intrinsic foot muscle test (IFMT). Mann-Whitney U and independent t-tests were used to examine between group differences. Results: Individuals with PHP exhibited a more pronated foot posture and greater plantar fascia thickness at the proximal insertion compared to healthy controls. Plantar sensation thresholds were higher in the PHP compared to healthy controls at the head of the first metatarsal. There were no group differences in abductor hallucis morphology or IFMT performance. Conclusions: Individuals with PHP exhibited a more pronated foot posture, thicker plantar fascia, and diminished plantar tactile sensation.