The plantar fascia is a thick, multi-layered, non-elastic fibrous tissue band that extends along the plantar surface of the foot.The configuration of the plantar fascia is generally considered as a dense, longitudinally arranged fiber band divided into medial, central, and lateral components. The most significant functional role of the plantar fascia is to maintain the arch structure of the foot, providing a stable support base while standing and absorbing dynamic reaction forces during walking.Pes planus is a rather general term with many definitions. Staheli described pes planus as a "foot with a broad base of support," commonly known as flatfoot in layman's terms. In a study involving 80 female participants aged 65 and older, 90% of foot deformities observed while standing were identified as pes planus. Generally, pes planus is a condition characterized by excessive pronation of the rear part of the foot and a lowering of the medial longitudinal arch. During the push-off phase of walking, the pronation moment generated by the ground reaction force flattens the arch as the subtalar joint rotation combines. The shift in position in the talus bone causes the navicular bone to drop. The plantar calcaneonavicular ligament tightens, and the tibialis posterior muscle lengthens. Abnormalities in the bones of the foot, dysfunction of the tibialis posterior muscle, Achilles tendon shortening, or muscle weakness can contribute to pes planus. Individuals with pes planus may experience foot and leg pain with exercise, physical activity, and prolonged walking, which can limit their level of physical activity. Research has examined the relationship between pes planus and various physical parameters, and it has been found that one of these parameters, balance, is negatively affected by the presence of pes planus.

Participant information, including age, gender, height, body weight, and body mass index, was recorded using a general form. Dynamic and static balance was assessed before and after the interventions in the study groups. Three specialist physiotherapists conducted measurements and evaluations (navicular drop, static and dynamic balance). The assessing physiotherapist remained consistent throughout, and they were unaware of the participant groups. An expert in manual therapy administered the MRTs. Statistical analysis was performed by a separate researcher uninvolved in the practical aspects of the study.

Inclusion Criteria:

• volunteering for study participation,
• being between the ages of 18-25
• presence of pes planus.

Exclusion Criteria:

• Presence of orthopedic conditions other than pes planus,
• having a history of lower extremity surgery
• presence of neurological or rheumatological disorders,
• having a problem with vision or hearing
• participating in regular physical activity (>150 min/week)

It is not yet known if there will be a plan to make IPD available.