Foot Posture and Balance in Children With Flexible Flatfeet: Effects of Mud-walk

FPI-6 is a clinical tool for quantifying foot positioning that uses established criteria. The FPI consists of the following six items, each graded on a scale of -2 to +2 referring to the position of the forefoot, midfoot and hindfoot, and the three planes of motion:

• talar head palpation;
• symmetry of supra and infra lateral malleolar curvature;
• inversion/eversion of the calcaneus;
• prominence in the region of the talus-navicular joint;
• height of the medial longitudinal arch;
• abduction/adduction of the forefoot. The FPI thus obtained ranges from -12 (highly supinated) to +12 (highly pronated).

It can be

• highly pronated (+10 to +12)
• pronated (+6 to +9)
• normal (0 to +5)
• supinated (-1 to -4)
• highly supinated (-5 to -12). FPI-6 demonstrates a perfect weighted kappa value (Kw = 0.86), with a high intra-rater reliability (ICC = 0.96)

Navicular Drop Test is used to evaluate the amount of foot pronation. It is considered as a reliable and valid tool to measure static navicular height. The navicular height is measured while the child is sitting with barefoot flat on a platform with 90◦ knee flexion and the subtalar joint in neutral position. The Navicular drop is recorded as the difference in navicular height between subtalar joint neutral position and relaxed standing. Navicular drop more than 9 mm represented a pronated foot type, 5-9 mm a neutral foot and less than 5 mm a supinated foot. This test's intra-rater and inter-rater reliability has been demonstrated to range from 0.73 to 0.96 .

A 14-item criterion-referenced measure that examines functional balance in the context of everyday tasks in the pediatric population. Each item level scores range from 0-4 which is determined by the ability to perform the assessed activity. Maximum score = 56 points with 56 points being a perfect score. Test-retest (ICC2,1 = 0.923), interrater (ICC2,1 = 0.972), and intra-rater (ICC2,1 = 0.895-0.998) are reliabilities of PBS. It has high internal consistency (Cronbach α = 0.94) .

Single leg hop test assesses functional performance of lower limb. The test method involves performing a forward jump, covering the maximum possible distance with one foot, landing on the same foot, and finally maintaining balance for at least 2 seconds. After performing 2 or 3 attempts, the individual executes a complete single-leg hop with the dominant leg, and the distance covered is recorded. An intra-class correlation coefficient (ICC) of over 0.85 has been reported for the reliability of this test in various studies.