Kinematic and kinetic parameters of gait have a significant dependency on subject age and walking velocity. Hip flexion-extension, stride length, hip resultant force, hip resultant moment, and hip contact force all increase with increasing velocity. All of these parameters except hip resultant force are significantly affected by the age of the subject. The evaluation of patients with lower extremity problems utilizing such gait parameters must be conducted with an appreciation of normal values corrected for subject size, age, and walking velocity.