IRCT2016031626661N1 IRCT 2016-03-16 Department of Sport Medicine, Faculty of physical education and sport sciences, Tehran University The Effecte of foot orthosis on electromyographic activity of ankle muscles during single leg jump landing The Effecte of foot orthosis on pattern and electromyographic activity of ankle muscles in collegiate athletes with flat foot during single leg jump landing 2015-05-22 anticipated 15 Complete https://irct.ir/trial/22027 interventional Randomization: N/A, Blinding: Not blinded, Placebo: Not used, Assignment: Single, Purpose: Prevention. N/A Flexible Flat Foot. In people with flat foot deformity to correct and support foot arch, rigid or semi-rigid foot orthosis may be recommended. In these study used a semi-rigid prefabricated foot orthoses with medial longitudinal arch that’s inclusive of two harder EVA (Ethylene Vinyl Acetate) layer at below and a surface layer is made of softer leather layer. In addition, this foot orthoses have a metatarsal pad to support foot transverse arch. The benefits of this type of foot orthoses include of durable, affordable and save time (no need for molding) that lead to its widespread use in orthotics clinics. It is generally accepted that the orthotics are effective on the sensory input of foot mechanoreceptors, these effects could increase or decrease their foot sensory feedback..