Flexible flatfoot is one of the most common types of flatfeet. It has an arch that is present in open kinetic chain and lost in closed kinetic chain Balance is defined as the process that maintains the center of gravity within the body's support base.

Pilates exercises is a whole body conditioning program which was initially used for managing low back pain and improving balance in elderly. Now-a-days it is used for posture correction and fitness training.

Individuals with flatfeet are more unstable when compared with normal individuals during quiet standing. About 10% to 25% of population exhibits a flat foot to varying degrees. In clinical practice, some subjects become symptomatic with feet pain or lower extremity soreness and limitation in their functional activities such as limitation of long-distance walking or running and high-impact sports.Patients with flexible flat feet have poorer static and dynamic balance than healthy individuals. Taking into consideration effect of flat feet on body alignment, the implication of flat feet on balance have received little attention to date Pilates is an individual body-based exercise, it has an advantage in that exercise load can be controlled according to the body's center of balance.Pilates based exercise works on the principles of trunk stability, also known as "core stability". "Core is described as a box, with the abdominals (transversus) in front, paraspinals (multifidus) in back, diaphragm in top and pelvic floor at the bottom". Pilates is a popular form of exercise training program which includes series of stretching and strengthening exercises with proper trunk control and breathing.

Inclusion Criteria:

1. Subject's age ranged from 18-21 years old
2. Subjects had bilateral pronated feet posture according to the Navicular Drop Test by Brody method: normal feet (between five and nine mm of navicular drop), a pronated foot (more than 10 mm of navicular drop)
3. Body Mass Index (MBI) ranged from 18.5 to 25 kg/ m2

Exclusion Criteria:

• 1-Repeated lower extremity injuries as fractures or deformities. 2-History of surgery to the lower extremity. 3- Any neurological deficit affecting balance. 4-Any medication can affect the balance. 5- pregnant and breast feeding females