Gait Analysis – What Can It Tell Us?
Part I
by Brie Darcy, PT, DPT
Try the following exercise – close your eyes and picture three people walking. Imagine the first person is walking very quickly. They are taking long, fast steps and their arms are swinging rapidly from side to side. How do you imagine this person is feeling? Now, imagine the second person walking. Their posture is stooped and their head is hung low. They are walking much more slowly, maybe even with their feet scuffing the ground. How would you expect that they be feeling? The third person, on the contrary, has a bit of a perky bounce to their steps. What might their mood be like?
If you guessed that person #1 is in a hurry, person #2 is feeling sad, and person #3 is happy – you would likely be correct.
The process that you just performed could be considered “gait analysis.” By simply examining characteristics of their walking patterns you were able to draw conclusions. In this example, you matched the quality of their walking with how they were feeling – in a hurry, sad, and happy.
The inferences just made were based on overt or easily recognizable factors, ones that you can visually see with your eyes. Experts in the field of walking or “gait”, however, take this process much further. By examining the very subtle, detailed factors that characterize one’s walking patterns, they have discovered that we can learn much, much more – aspects such as someone’s likelihood of suffering a fall and even the development of certain diseases.
Before diving further into this topic, let’s review the basic fundamentals of walking.
The Complexity of Walking
Walking or “gait” is one of the most complex and integrated human activities. While it is an activity that we learn at a very young age (typically in infancy), it actually requires a coordinated effort of multiple physiological systems. The factors that generate (and can influence) walking are numerous. These factors can be classified into 6 physiologic subsystems that are involved in the gait process including:
(1) the central nervous system (the brain and spinal cord)
(2) the perceptual system (input coming from our senses such as vision and touch)
(3) peripheral nervous system (nerves outside of the brain and spinal cord)
(4) muscles
(5) bone/joints
(6) energy production/delivery
When these subsystems function in their ideal fashion, the result is the coordinated movement pattern we all know as walking.
The ‘Typical’ Walking Pattern
Below is a diagram of a typical gait cycle. A “cycle” of gait is measured from when one foot strikes the ground to the subsequent contact of the same foot. The gait cycle is further broken down into two primary “phases.” The stance phase consists on the entire time that the foot is on the ground. The swing phase is the entire time that the foot is in the air. During the gait cycle, each lower extremity passes through a stance and swing phase. While one limb is in the ‘stance’ phase, the opposite limb is in the ‘swing’ phase (except for a brief period of time when both feet simultaneously contact the ground). Each of these phases of gait is further broken down into subphases with a total of 8 subphases identified. The phases and subphases of gait can be seen in the image below.
[From: Pirker W, Katzenschlager R. Gait disorders in adults and the elderly : A clinical guide. Wien Klin Wochenschr. 2017;129(3-4):81-95. CC BY 4.0.]
Gait Dysfunction
When a disruptive process (such as an injury or disease) occurs that impacts the performance of any one of the systems mentioned above (think – a pulled muscle, a broken bone, or a chronic disease process) the pattern of walking can be substantially impacted. An impairment in the ability to walk is sometimes referred to as gait dysfunction. Gait dysfunction presents itself as an alteration in the pattern of gait seen in the diagram above.
Take a moment to imagine an individual walking with a sprained ankle. What do you picture? You probably imagine someone walking at a slow speed, likely with a limp and a lean to one side. You might also notice that they resist bearing weight on the side that is sore. This person’s gait has been altered as a result of an issue with a muscle or bone. Analyzing their gait, one might notice that they might have a shortened duration of ‘stance’ phase on their injured limb (perhaps due to pain putting weight through this leg). A related situation can occur when a person suffers a neurologic injury, such a stroke or traumatic brain injury. In these instances, the resulting gait dysfunction occurs as the result of impaired signals coming from the damaged area of the brain. The gait of an individual who has suffered a stroke might present with a shorter length of their steps, a shorter amount of time bearing weight on the weaker side, or perhaps, steps of unequal lengths.
Analyzing one’s specific pattern of gait can provide a wealth of insight into their health and functional status (amongst other factors). It can also be utilized as a tool for identifying specific treatment targets, tracking progress, characterizing fall risk, and even early identification of medical conditions.
Next month on our blog, we will dive into the second part of our gait analysis series. In Part 2 we will explore specific gait analysis methods, discuss the benefits to gait analysis, and provide insight into Moterum’s efforts to expand access to this important diagnostic and treatment tool.
Wishing you Health and Wellness,
The Moterum Team
References
1. Ferrucci L, Bandinelli S, Benvenuti E, et al. Subsystems contributing to the decline in ability to walk: bridging the gap between epidemiology and geriatric practice in the InCHIANTI study. J Am Geriatr Soc. 2000;48(12):1618-1625.