QUANTITATIVE ASSESSMENT OF GAIT: A SYSTEMATIC APPROACH
James J. Carollo and Dennis J. Matthews
Bipedal walking is a distinctive and uniquely human behavior that is celebrated in childhood and cherished across the life span. In the words of Dr. Aftab Patla, a renowned motor control expert who had a long and distinguished career at the University of Waterloo, "... nothing epitomizes a level of independence and our perception of a good quality of life more than the ability to travel independently under our own power from one place to another." Limitations in independent walking related to childhood disorders restrict education and employment options and access to social and cultural opportunities. Furthermore, a decline in walking ability directly affects the level of physical fitness so critical for health and well-being as we grow older, and contributes to a more sedentary lifestyle as an adult. Recent studies have linked habitual sedentary behavior to increased functional impairment and chronic disease risk in individuals with disability (1). This in turn can begin a cascade of chronic health issues and secondary conditions that can easily spiral out of control. Achieving and sustaining a functional level of walking ability is of the utmost importance to individuals with congenital or pediatric conditions and their families, and has a direct impact on their overall health status over their lifetime. Consequently, pediatric rehabilitation providers must be skilled in assessing walking and movement ability, and be comfortable utilizing all tools and techniques available to them to best manage their patients' care and expectations related to this most basic human function.
Over the last 25 years, instrumented gait analysis (IGA) has become more commonplace, evolving into an accepted, objective evaluation that can guide surgical and rehabilitation therapy planning for the child with personal mobility challenges. IGA provides a quantitative and comprehensive snapshot of one's characteristic movement pattern at a particular point in an individual's development or at discrete intervals in his or her treatment. Clinicians can use this information to describe the complex physiologic interactions that lead to abnormal movement and motor control, and better understand their impact on gait, movement, and other functional activities.
Observational gait analysis is a common topic during residency and most pediatric physiatrists are familiar with the procedures. However, training in the use of quantitative tools common to IGA and available from a modern clinical motion laboratory are frequently overlooked in postgraduate education, with the inclusion in the curriculum being highly dependent on the availability of such a facility during their training. Despite the advances in technology that have made IGA more commonplace in clinics around the world, only a handful of Physical Medicine & Rehabilitation (PM&R) residency programs are associated with motion analysis facilities. Even fewer are associated with clinical motion laboratories accredited by one of the two independent accreditation organizations, the Commission for Motion Laboratory Accreditation (CMLA) in North America, and the Clinical Movement Analysis Society (CMAS) of the United Kingdom and Ireland. Laboratories that have achieved accreditation conform to common standards of practice, quality, and information reporting that are the benchmark for IGA in clinical practice. This chapter can be used as a guide for those interested in utilizing data from accredited facilities in their practice regardless of their level of exposure to IGA in the past.
Mastery of IGA procedures along with the ability to perform meaningful interpretations that are clinically relevant remains challenging for many clinicians. We believe underutilization of modern gait analysis techniques in pediatric rehabilitation is related to the difficulty associating gait deviations seen in an IGA report with specific functional deficits during the walking cycle. Fundamental to making this connection is a clear understanding of the functional demands of normal gait. Armed with this understanding, the essential features of normal, efficient locomotion can be easily recognized, and this provides the basis for identifying the absence of these features in the child with gait dysfunction. When applied systematically, this evidence-based approach can provide a logical strategy for clinical gait analysis and the management of gait disorders (2).
Therefore, the goal of this chapter is to familiarize clinicians with fundamental gait analysis principles by focusing on the inherent functional requirements of normal locomotion. This provides a framework for using specific measurements from an IGA report to pinpoint the joint and/or muscle system responsible for a particular functional deficit, and the subsequent target for clinical intervention.