METHODOLOGY: Forty participants with no evidence of LLD were recruited. Height and TL were measured. Reflective markers were attached at specific points in lower extremity and subjects walked in gait lab at a self-selected normal walking pace with artificial LLDs of 0, 1, 2, 3, and 4 cm simulated using shoe raise. Accommodation period of 30 min was given. Infrared cameras were used to capture the motion. Primary kinematic (knee flexion and pelvic obliquity (PO)) and secondary kinetic (ground reaction force (GRF)) were measured at right heel strike and left heel strike. Functional adaptation was analyzed and the postulated predictor indices (PIs) were used as a screening tool using height, LLD, and TL to notify significance.

RESULTS: There was a significant knee flexion component seen in height category of less than 170 cm. There was significant difference between LLD 3 cm and 4 cm. No significant changes were seen in PO and GRF. PIs of LLD/height and LLD/TL were analyzed using receiver operating characteristic curve. LLD/height as a PI with value of 1.75 was determined with specificity of 80% and sensitivity of 76%.

METHODS: Eighteen male healthy subjects volunteered to participate in the experiment. Walking gait analysis was conducted with eight different levels of insole to simulate the LLD, starting from 0 cm until 4.0 cm with 0.5 cm increment. Qualisys Track Manager System and C-motion Visual 3D biomechanical tools were used to analyse the results. Four joints (ankle, knee, hip, and pelvis) of lower limb of two legs were investigated. The increment of insoles was placed on the right leg to represent the long leg.

RESULTS: The results suggest that the mean contact forces for all joints in the short leg were increased as the increment level increased. On the contrary, the mean contact forces in the long leg decreased when the LLD level increased. Among these four joints, JCF in hip shows a positive increment based on the ASI value. Means that hip shows the most affected joint as the LLD level increase.