Anthropometric Profile of Leg Length Inequality and its Impact on Gait

Leg length inequality (LLI) affects gait - primarily pelvic and torso movements. LLI is present in around 40-70 % of the healthy population. Due to LLI's significant impact on the body, as well as the possible occurrence of a variety of associated health problems, the aim of this research is to determine whether there is a significant difference in pelvic movement in all three planes, depending on the degree of LLI. This study was conducted on a sample of 30 healthy subjects. The functional length of lower limbs was measured. When LLI was calculated, kinematic measures were taken of pelvic and lower limb movements during gait using 3D cameras and (c) Vicon Motion Systems Ltd. UK. The obtained data on kinematic pelvic movement in all three planes during gait were compared with the reference values. The results show that there is no statistically significant difference in pelvic movement about the axes x, y, and z in cases of LLI of up to 18mm (p>0,05). There is a statistically highly significant positive correlation between the difference in functional leg length (r=0,575; p=0,008) and femur length (r=0,525; p=0,015) on one hand, and the difference in pelvic movement about the axis x on the other, compared to the reference values. In a healthy population with LLI from 0 to 18 mm, gait remains unaffected and an increase in LLI predominantly affects pelvic movement about the horizontal axis (x) - pelvic tilt, which exponentially increases with an increase in femur length discrepancy.