Gait analysis is the study of the walking or running pattern of an individual. This can include spatial and temporal measurements such as step length, stride length and speed along with angular measurements of various joints and the interplay between various parts like the foot, hip, pelvis or spine when walking. Gait analysis can be used to assess clinical conditions and design effective rehabilitation; for example, following limb injury or amputation, or other disorders such as a stroke or Parkinson's diagnosis. It can be used to influence intervention decisions, such as whether a patient should undergo surgery, further physiotherapy, or begin a particular treatment regime. Gait analysis can also be used in sports science to monitor and review performance and technique.
Gait can be recorded in a variety of ways, including pressure sensors, force plates, in-shoe pressure systems, through marker-based or marker-less systems using various cameras or sensors to calculate body positions in a set sequence of movements.
This book focuses on both the hardware systems for collecting data as well as data visualisation and mathematical models for interpreting the data. It is written by a range of international researchers from academia, industry, and clinical settings, providing a complete overview of gait analysis technologies suitable for an audience of engineers in rehabilitation technologies or other biomedical engineering fields.
Inspec keywords: kinematics; muscle; prosthetics; orthotics; cameras; gait analysis
Other keywords: sport; cameras; muscle; gait analysis; electromyography; orthotics; kinematics; biomechanics; prosthetics; legged locomotion
Subjects: Physics of body movements; Prosthetics and other practical applications; Prosthetics and orthotics
Gait analysis has many uses in fundamental research, clinical research and practice, and sports and exercise science (without even mentioning non-human gait). In all these cases, technology plays a key role. Huge technological progress has been made since the early pioneers of gait analysis, and new technologies are currently emerging at an ever-increasing pace. This allows not only for an improved quality of data but also makes gait analysis accessible to a much larger and non-specialist audience. This book will outline the past, present and future of these technologies and techniques in gait analysis.
Homo Sapiens have evolved to walk with their body upright, neither leaning forwards or backwards with an even stride and arms swinging at the side, conventionally described as gait. Locomotion when in the upright position is facilitated by attempting to hold a constant centre of mass to achieve good balance and economy, expressed as unit energy consumed against distance travelled. The emergence of an evolutionary advantage through efficient bipedal locomotor capability continues to remain a research focus to correlate validated motion and applied forces with measurements of the morphology and anatomy of primates, early hominins, and humans.
Modern biomechanical movement analysis is undertaken using motion capture (camera) based systems. Simple 2-D dimensional analyses which are now almost completely limited to field-based analyses require as little as one camera, whereas 3-D examinations of human movement can require many cameras depending on the movement and space requirements of the examination. From a 3-D analysis standpoint, it is important to consider several factors to optimise the quality of the kinematic data (on which this chapter focusses) that you collect and maximise its usefulness in both clinical and sports settings.
Kinetics examines the relationship between the forces acting on the body and how these forces affect motion. Ground reaction force, joint reaction force and muscle force are the major forces involved in human locomotion. This chapter will focus on ground reaction force; force provided by a supporting horizontal surface.
While it is rarely something that is consciously thought about, walking requires careful coordinated organisation of multiple groups of muscles. Exactly how muscles work has been an active area of research for decades. Researchers and clinicians consider many questions about muscle function in human movement, for example: When do muscles start/stop working?; Which muscles work together?; Which muscles work in opposition?; What intensity do muscles contract at?; How much energy does it require for the muscles to function?; Where does the energy required come from?; How does footwear, orthotics or prostheses affect muscle function?
Many other questions have stimulated past and present research activities, and there is an exciting future for new and innovative lines of enquiry into the function of muscles but with firm foundations from the previous decades.
This chapter aims to provide readers an overview of important aspects of muscle function and measurement through electromyography (EMG), however is far from an exhaustive exploration of EMG, and interested readers will be directed to further reading after we hope this chapter piques your interest.
This chapter has covered a range of topics - from the early days of gait analysis in the time of Marey, to modern examples of the use of wavelet analyses and coherence estimates of brain-muscle coupling. Whatever aspect of gait may be of interest to a student, researcher, physician, or allied health professional, it is important to heed the concerns expressed by Brand and Crowninshield almost 40 years ago. Data that are collected should not be directly observable (why buy expensive equipment when you can look at a patient and make a decision on pathology or recovery status?). Moreover, the data should allow one to distinguish normal from abnormal, be reproducible, and in a form that can be communicated in clinician-friendly graphics.
The widespread development and implementation of routine clinical gait analysis across the world have had a secondary benefit with many new applications being discovered for the technologies in disparate but potentially commensurate environments including basic research, rehabilitation, ergonomics, virtual reality, engineering and animation to name but a few. Conversely, the unique demands of these environments have forged a symbiotic relationship where new requirements for technological improvements have directly benefited the original clinical and life sciences applications.
The purpose of clinical gait analysis is to provide objective data from which a treatment plan designed to improve gait, in the setting of complex neuromusculoskeletal diseases and injuries, may be based. The impairments that result from these conditions often affect a patient's posture and locomotion as well as their ability to conduct other purposeful movements and activities of daily living. The essence of the clinical gait analysis process is to obtain an integrated understanding of a patient's atypical structure, challenged control, and biomechanically altered function. From this deeper understanding, a team skilled in the process will be able to develop a well-conceived plan to provide the appropriate combination of physical therapy, orthotic and prosthetic management, and surgical care to meet the patient's and physician's expectations.
Human gait is considered as a complex movement where the evolutionary aspects of the musculoskeletal system including the upper limbs, lower limbs, and spine, synchronize to facilitate bipedal propulsion. Coordination of lower limbs on the movement of the body, with the assistance of the trunk, maintains the balance and interaction of this complex with the upper limbs. Increasing the efficiency of the movement makes human gait a very particular phenomenon.
We describe techniques of video-based gait analysis and their application to forensics in this chapter. First, we describe a brief history of the development of video-based gait analysis techniques including early human perception-based one, model-based and appearance-based gait representations, machine learning techniques, and recent deep learning approaches, as well as its use cases in forensic purposes in the world. We also describe our gait verification system for criminal investigation, which is composed of subject enrollment, silhouette extraction, and verification with feature extraction, where a user, i.e., a criminal investigator, confirms the correctness at each stage step by step. The gait verification system copes with a variety of circumstances including view angles, image size, frame-rate, and region to be masked out of matching. We then elaborate on a situation of gait forensics with the developed gait verification system in Japan and conclude this chapter with a summary and future direction of the gait forensics.
Clinical gait laboratories providing detailed kinematic, kinetic and electromyographic analyses will continue to play a central role but there will also be a supportive place for wearable devices such as IMUs, depth cameras and artificial intelligence capable applications initially for home and outdoor use but potentially in future clinical environments. The continually expanding experience and competencies in the robust measurement of human motion combined with the rapid development and improvements in models, existing and emerging technologies will ensure that the future of gait analysis remains positive. The most likely future will draw upon a fusion of data acquired from available technologies that will further enhance treatment decision-making and so benefit patients and subjects alike.