In the human body, the base ofsupport is the feet, it contains bones which are held together by muscles andligaments. In the foot there are three arches, the longitudinal medial arch,longitudinal lateral arch, and the transverse arch.
The pressure of the weightof the body is absorbed by the medial longitudinal arch, and this arch length couldshorten due to ligaments laxity or foot muscles weakness. (Pourghasem et al., 2016)The foot works as a lever, and thebody weight is borne by it, normally the center is where the weight and strainfall through the foot, and the muscular activity helps in balancing the weightand strain. The muscle which helped in balancing the weight will stopsupporting the foot if it stops to function as a lever. This condition of aweak foot is recognized as flatfoot, which is now no longer works as a leverbut is causing pain and physical discomfort. There are three most visible deformity elements, thefoot takes the valgus position, and the body weight falls on its inner area,while the leg rests on the displaced talus it changes its position and turns in,and the foot turns out, this leads to shifting the strain line that transmitsthe power to the fulcrum to deviate from center of the foot to its inner side,in relation to the leg the foot is abducted or everted. The arch is becomingbroad and flat, causing the foot to be flat.
(Whitman, 2010)Flatfoot is the most common type ofthe deformity in the foot, changes in the skeletal structure, ligaments, andmuscles occur due to it, the change in the tarsal bones leads to transformationin its motion mechanism thus the fatigue is triggered, arthritis and a deformitywhich is secondary to it happens in the front part of the foot. Pain and fatigueare reproduced by walking or standing. The foot function is impaired whenpracticing sports or excessive activities, in flatfoot damage to the lower limboccurs due to the load on the tibia causing pain to it and the knees.(Seo and Park, 2014)The flatfoot condition can becategorized to congenital or acquired, and the congenital type can be dividedinto two flexible and rigid. In flexible flatfoot, the medial longitudinal archappears when the foot is in a non-weight bearing position and disappears whilestanding, in the rigid flatfoot the arch is absent even when the foot assumes anon-weight bearing position.
(Pourghasem et al., 2016) The World Health Organization stated that lessthan 1% of the population is affected by Rigid flatfoot which causes pain anddisability that may require surgery. While in the U.S.
adult population between2 to 23% is affected by flexible flatfoot.(Banwell et al., 2014)Symptomatic Flatfoot is considered pathological, the hindfoot medial region and the posterior tibial tendon iswhere the pain generally occurs, sometimes it may be associated with the tendonsheath effusion.(Toullec, 2015)Painfulsymptoms accompanying flexible flatfoot include, a wide distribution of painand an increase in fatigue rate in lower limb area, osteoarthritis, achillestendinopathy and patellofemoral disorders may appear. Other signs observedinclude the abnormal appearance of rearfoot kinematics such as a rearfootexcessive eversion or by an increase in the eversion range, abnormal kineticsof the foot and ankle such as joint moments elevated or loading forces abnormalvalues and change in the physical function by abnormal timing and activation ofmuscles or by raising consumption of energy. These functional consequences arethe reason for