In this Q&A feature, Stephanie Wakeman, PT, DPT and Director of Clinical Operations discusses alongside Itamar Ben David, Product Manager, the development of OneStep’s novel fall risk assessment technology — and the potential future applications of such revolutionary motion analysis technology.
There are many clinically validated tools to assess fall risk. Why does OneStep use gait analysis?
Gait speed, often referred to as the "6th vital sign," remains vastly underutilized in healthcare, despite its well-established association with falls and functional status over the past couple of decades. Notably, Hsu-Ko et al. in 2006 made a significant discovery, revealing a robust correlation between gait speed, leg power, and late-life disability. In this study, they examined over 1700 subjects, assessing their ability to perform activities of daily living (ADLs) and engage in social activities. By measuring their leg muscle power and gait speed, they found a compelling link between peak leg power, gait speed, and disability.
In recognition of the significance of gait speed, a renowned white paper by Fritz in 2009 coined it as the 6th vital sign, emphasizing its significant correlation with various health factors. Subsequent research in 2015 further bolstered this theory, providing robust evidence supporting the correlation of usual gait speed with general health, cognitive decline, functional mobility, cardiovascular-related events, and even mortality, among other aspects.
Moreover, the temporal-spatial parameters of gait speed, stride length, and stride variability have consistently demonstrated strong correlations with fall risk in hundreds of studies. Fortunately, advancements in technology have made it feasible to measure these vital gait parameters with limited equipment, such as a smartphone, thus making it an easily accessible way to assess this essential parameter.
In light of these findings, it is evident that incorporating gait speed assessment into routine healthcare practices could yield invaluable insights into patients' overall well-being and potential health risks. By embracing this approach, healthcare professionals can proactively address fall risk, functional limitations, and other health concerns, ultimately leading to improved patient outcomes and overall quality of life.
Why does OneStep’s fall risk assessment combine TUG, STS and fall history into the fall risk analysis?
The assessment of fall risk entails considering the significance of TUG (Timed Up and Go), STS (Sit-to-Stand), and fall history. Yet, it is important to recognize that evaluating each parameter in isolation exhibits limitations in terms of sensitivity and specificity. While TUG demonstrates specificity in assessing fall risk (0.74, 95% CI 0.52-0.88), its sensitivity appears comparatively low (0.31, 95% CI 0.13-0.57) based on certain studies.
STS, as a valid instrument for evaluating functional leg strength, has been associated with gait speed and fall risk in various investigations. Although direct links between STS and falls have been studied to a lesser extent, an example is provided by Applebaum et al.'s research. This study explored a modified STS in conjunction with fall history over a year, involving 53 adult veterans. The findings revealed correlations between fall risk (odds ratio = 0.75, 95% confidence interval = 0.58, 0.97) and the frequency of falls (incidence rate ratio = 0.82, 95% confidence interval = 0.68, 0.98).
Notably, a more comprehensive approach involves employing test item clusters, which yield a more robust clinical determination. Such an approach effectively enhances the sensitivity and specificity of any individual test conducted in isolation. Embracing this multifaceted perspective allows for a more nuanced and accurate assessment of fall risk, thereby facilitating informed decision-making and tailored interventions to mitigate potential fall-related complications.
Can gait help to assess other conditions as well?
Certainly! Gait, particularly gait speed, is intricately linked to various aspects of our overall health and functionality, including cardiorespiratory fitness, functional mobility, and even longevity. The act of walking at a particular speed necessitates a certain level of endurance, strength, and cardio-respiratory fitness. In the context of modern society, the ability to maintain a specific walking speed is crucial for ensuring safety and independence in our daily lives.
To illustrate this point, consider the importance of walking speed when crossing streets in urban environments. Research indicates that in order to safely navigate a street with a width of approximately 13 feet, individuals should be capable of walking at an average speed of 1.1 m/second (equivalent to 2.4 miles per hour). This allows sufficient time to negotiate curbs and reach the other side before the traffic light changes. The ability to meet this walking speed requirement is essential for performing basic tasks like shopping, attending appointments, and commuting to work, all of which are central to maintaining an active and fulfilling lifestyle.
Furthermore, examining other aspects of gait, such as step length, consistency or stance time in each leg, can provide valuable insights into joint function and the ability to execute consistent, repetitive motions. These measures can serve as potential indicators of underlying musculoskeletal or neurological impairments that may affect an individual's overall mobility and physical health.
In summary, gait and its various components, particularly gait speed, play a significant role in gauging our overall health, functional capabilities, and even our ability to live independently. By understanding and assessing different aspects of gait, healthcare professionals can gain valuable information about an individual's physical well-being and potential areas of concern. Ultimately, this knowledge empowers us to take proactive steps towards promoting better mobility, preventing health issues, and enhancing overall quality of life.
Kuo HK, Leveille SG, Yen CJ, Chai HM, Chang CH, Yeh YC, Yu YH, Bean JF. Exploring how peak leg power and usual gait speed are linked to late-life disability: data from the National Health and Nutrition Examination Survey (NHANES), 1999-2002. Am J Phys Med Rehabil. 2006 Aug;85(8):650-8. doi: 10.1097/01.phm.0000228527.34158.ed. PMID: 16865019; PMCID: PMC2366087.
Middleton A, Fritz SL, Lusardi M. Walking speed: the functional vital sign. J Aging Phys Act. 2015 Apr;23(2):314-22. doi: 10.1123/japa.2013-0236. Epub 2014 May 2. PMID: 24812254; PMCID: PMC4254896.
Applebaum EV, Breton D, Feng ZW, Ta AT, Walsh K, Chasse´ K, et al. (2017) Modified 30-second Sit to Stand test predicts falls in a cohort ofinstitutionalized older veterans. PLoS ONE 12(5):e0176946. https://doi.org/10.1371/journal.pone.0176946