Quantitative comparison of gait strategy between stiff knee gait caused by rectus femoris spasticity versus that caused by femoral anteversion was the objective of this study. Twenty-three diplegic were divided into group 1 (excessive femoral anteversion without rectus femoris spasticity) and group 2 (normal femoral anteversion and rectus femoris spasticity). Both groups showed low knee flexion during swing (KMSw), but although group 1 exhibited normal KMSw timing and high hip intrarotation, group 2 presented delayed KMSw timing, with normal hip rotation. Reduced KMSw may be because of two different conditions: excessive femoral anteversion, leading only to KMSw reduction, and rectus femoris spasticity, inducing coexistence of reduced KMSw and its delayed timing.