The aim of this study is to examine the plantar fascia and Achilles tendon thickness and flexibility in individuals with pes planus. Individuals between the ages of 18-45 who have been diagnosed with pes planus by an orthopedist and healthy individuals with similar demographic characteristics will be included in the study as a control group. Demographic information of the individuals will be recorded and clinical evaluations will be made. The foot posture of the individuals participating in the study will be evaluated with the Foot Posture Index, and the degree of flat feet will be evaluated with the Navicular Drop Test. The Achilles tendon and plantar fascia thicknesses of the individuals participating in the study will be measured with ultrasound, and the plantar fascia and Achilles tendon flexibility will be measured with a myotonometer.