This book discusses gait, the control of gait and how different pathological conditions may affect gait, with a unique application of a gait study reviewed at the end. We first discuss methodology issues related to gait quantification and interpretations of different gait-related measures and their theoretical relevancy and clinical applications. The effects of different pathological conditions on gait were then discussed, using diabetic peripheral neuropathy, Parkinson's disease, concussions and lower back pain as examples. A current understanding of how anatomical alternation, central nervous system lesions or the loss of a limb affects gait have been reviewed in two different chapters. Postural control of gait has been examined from both central and peripheral perspectives, while stationary and while walking. The neuromuscular system and how it helps to control an inherently unstable postural system is also discussed, as well as the introduction of the common theories of postural control during standing and walking. The last chapter of the book introduces a novel use of gait studies -- gait biometrics were used as a unique identification of any individual based upon their specific characteristics. A person's gait may uniquely identify them and be used to help control access or in surveillance. The book summarises our current understanding of gait and gait studies. It can be used for college courses, post-graduate studies, as a reference to clinicians or anyone else who is interested in the human gait and gait studies.