New imaging tests aim to pinpoint the source of mysterious muscle pain

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion criteria for plantar fasciitis group: * Clinical diagnosis of plantar fasciitis * Duration of plantar fasciitis pain greater than or equal to 3 months * Severity of plantar fasciitis pain greater than or equal to 3/10 Inclusion criteria for Achilles tendinopathy group: * Clinical diagnosis of insertional Achilles tendinopathy: * Duration of Achilles tendinopathy pain greater than or equal to 3 months * Severity of Achilles tendon pain greater than or equal to 3/10 Control group: • Similar age, sex, and BMI as plantar fasciitis and Achilles tendinopathy groups Exclusion criteria: * Younger than 18 years of age * History of an invasive procedures to the foot and ankle on the side of interest * History of lower extremity injections, dry needling, or EPAT/ESWT within past 3 months on the side of interest * Contraindications for MRI (e.g. non-MR compatible implanted devices, claustrophobia, inability to remain still comfortably for 1 hour in a supine position, body size too large for MR scanner) * Clinically unstable medical or psychiatric issues * Pregnant or possibly pregnant * Co-morbidities associated with changes in musculoskeletal imaging, including: Diagnosed systemic conditions affecting the foot and ankle (e.g., rheumatoid arthritis, spondyloarthropathy, gout) endocrine disorder with complications (e.g., uncontrolled Type I or II diabetes, diabetic peripheral neuropathy) Neuromuscular diseases (e.g., Charcot-Marie-Tooth (CMT) disease) Connective tissue disorder (e.g. Marfan's syndrome, Ehlers-Danlos) Osteoarthritis of the foot or ankle History of foot or ankle fracture Infection of the foot or ankle (e.g., infectious fasciitis, calcaneal osteomyelitis) within the past year Familial hypercholesterolemia Neoplasms involving the foot, Plantar fibromatosis * Control group only: Persistent or recurrent leg pain in the past 6 months * Plantar fasciitis and Achilles tendinopathy groups only: Other source of heel or foot pain (e.g., tarsal tunnel syndrome, peripheral neuropathy, lumbar radiculopathy, calcaneal stress fracture, Morton's neuroma, fibromyalgia) or co-occurring plantar fasciitis and Achilles tendinopathy (for the Achilles tendinopathy group).