Comparison of flat footed children with and without hypermobility by static and kinetic gait analysis

Hypermobility is a clinical condition that can occur alone or in combination with other diseases in children. The aim of this study was to compare the static and kinetic gait analysis of flat feet in children with and without hypermobility. The research was carried out at Hacettepe University Faculty of Medicine, Department of Anatomy and Health Sciences University, Ankara, Turkey and Sami Ulus Gynecology, Child Health and Diseases Training and Research Hospital. A total of 100 children comprised of 50 healthy and 50 hypermobile participants ranged between 5-11 years (X±SD = 8.14±1.91) were included into the current study. The motion of the body in space has been studied by Step analysis and Ground Force Measurement (force plates) methods. Joint angles, linear and angular velocities and accelerations of the trunk, pelvis, legs and feet in all three planes were measured and recorded as a numerical data. A software program (Milletrix Applicazione, Diagnostic Support S.R.L.) calculated the change in joint angle with the displacement of the signals reflected from the pointing devices on the patient in space. During walking, velocity was calculated from the displacement from one time unit to the other time unit, and acceleration was calculated from the velocity change. Kinematic data were recorded using optical cameras, walkways with sensors, and electrogoniometers. In the pedobarographic examination, the pressure points of the foot were determined. Data were analyzed using two independent groups t-test, Welch's t-test, and Mann-Whitney U test (p<0.05). A significant difference was found between the amount of load on the fore and hind legs of both normal and hypermobile children (p<0.001). In all children, the back foot is more loaded. There was no significant difference between normal and hypermobile children in terms of foot progression angle in both left and right feet (p=0.536; p=0.540). There was no significant difference between normal and hypermobile children in terms of double stride length and stride width (p=0.899; p=0.562). There was no significant difference between normal and hypermobile children in terms of speed and cadence (p=0.072; p=0.051). However, there is a significant difference between normal and hypermobile children in terms of stance and swing phase duration (p<0.001; p<0.001). While the duration of the stance phase is longer in hypermobile children, the duration of the swing phase is longer in normal children. For this reason, the stance phase is longer in children with hypermobility, while the swing phase is shortened in children with balance disorders, so the durations should be carefully evaluated.