Effect of Biodex Balance Training and Short Foot Exercise on Myoelectric Activity of Paraspinal Muscles in Subjects with Flexible Flatfoot

Inclusion Criteria: * 1\) Sixty subjects from both gender with bilateral flexible flat foot will be selected with their age between 18 to 30Years old 2) Body Mass Index (BMI) was ranging from 18 to 25 kg/m2 3) The participants were eligible to be included if had bilaterally FFF according to the navicular drop test 4) Required participant to have been diagnosed (by an orthopedist) with flexible flat foot Exclusion Criteria: * Repeated lower extremity injuries as fractures or deformities. 2) History of surgery to the lower extremity. 3) History of cerebral concussions, and visual or vestibular disorders. 4) Any neurological deficit affecting balance. 5) Any medication can affect the balance 6) Any problem of lumbar spine( disc,spondylolisthrsis)