A Scoping Review of the Validity and Reliability of Smartphone Accelerometers When Collecting Kinematic Gait Data.

The aim of this scoping review is to evaluate and summarize the existing literature that considers the validity and/or reliability of smartphone accelerometer applications when compared to 'gold standard' kinematic data collection (for example, motion capture). An electronic keyword search was performed on three databases to identify appropriate research. This research was then examined for details of measures and methodology and general study characteristics to identify related themes. No restrictions were placed on the date of publication, type of smartphone, or participant demographics. In total, 21 papers were reviewed to synthesize themes and approaches used and to identify future research priorities. The validity and reliability of smartphone-based accelerometry data have been assessed against motion capture, pressure walkways, and IMUs as 'gold standard' technology and they have been found to be accurate and reliable. This suggests that smartphone accelerometers can provide a cheap and accurate alternative to gather kinematic data, which can be used in ecologically valid environments to potentially increase diversity in research participation. However, some studies suggest that body placement may affect the accuracy of the result, and that position data correlate better than actual acceleration values, which should be considered in any future implementation of smartphone technology. Future research comparing different capture frequencies and resulting noise, and different walking surfaces, would be useful.

COVID-19: Social Distancing and Physical Activity in United Kingdom Residents With Visual Impairments.

Introduction: The introduction of the COVID-19 lockdown and social distancing policy has the potential to restrict access to physical activity, change exercise behavior, and to increase sedentary behavior. This study was conducted with the support of British Blind Sport and evaluates the effect of the lockdown policy on adults with visual impairments in the United Kingdom (UK). Methods: An online survey based on the World Health Organization's Global Physical Activity Questionnaire was completed by 73 participants (median age 35-44 years, 59% female) to gain information on how the implementation of the lockdown policy by the UK government has affected physical activity and sedentary behavior in adults that are visually impaired. Paired sample t-tests and Wilcoxon signed rank tests were used to analyze continuous and Likert scale data, respectively. Results: The majority of participants continued to exercise during lockdown, but the nature of this activity altered with a significant change to exercising in a private indoor space (+190% (always), z = -3.871, p < 0.001), and those exercising alone (+118% (always), z = -2.595, p = 0.009). The volume of activity reduced in all cases, between -11% and -52%, with significant changes in duration of vigorous day-to-day activity, moderate day-to-day activity, travel by foot or cycle, and vigorous recreational activity. Sedentary behavior increased on average by 21% (t(59) = -2.050, p = 0.045), with a greater effect seen in females (+36%, t(35) = -2.525, p = 0.016). Discussion: Reductions in physical activity volume and increases in sedentary behavior are consequences of the UK lockdown for those with visual impairments. The health and well-being implications of these data to this specific population are of particular concern. Implications for Practitioners: Lockdown measures should be designed with consideration of the needs of people with disabilities. Innovative ways to engage these populations in physical activity are strongly encouraged.

Evaluating consistency of physical activity and exercise prescription in the UK for people with diabetes - a Delphi study.

Introduction: Increased physical activity is recommended as a cost-effective measure to tackle long-term management of people with diabetes, but research on interventions lacks consistency in terms of effective duration and modality. Methods: The aim of this study was to evaluate expert consensus on exercise and physical activity prescription via a three-round Delphi study conducted with 45 UK-based health and fitness professionals experienced in prescribing exercise or physical activity to people with diabetes. Results: The majority of items put forward to the panel reached consensus with 70% or above voting these items as important, but the details of the type, duration and/or modality of exercise or physical activity prescription within these items often contradicted each other, suggesting that patients are receiving inconsistent advice. The range of different exercise prescription found in this study suggests that patients are being given inconsistent and potentially confusing advice, which may affect their participation in exercise and long-term lifestyle change. Conclusion: More consistent promotion of advice from healthcare and fitness professionals may help with increasing physical activity in this participant group and achieving long term behavior change, reducing patient symptoms as well as reducing the cost to the National Health Service (NHS).

COVID-19: self-reported reductions in physical activity and increases in sedentary behaviour during the first national lockdown in the United Kingdom.

Purpose: The United Kingdom (UK) government imposed its first national lockdown in response to COVID-19 on the 23rd of March 2020. Physical activity and sedentary behaviour levels are likely to have changed during this period. Methods: An online survey was completed by n = 266 adults living within the UK. Differences in day-to-day and recreational physical activity (at moderate and vigorous intensities), travel via foot/cycle, and sedentary behaviour were compared before and during the initial COVID-19 lockdown. Results: The median level of total weekly physical activity significantly reduced (- 15%, p < 0.001) and daily sedentary time significantly increased (+ 33%, p < 0.001). The former was caused by a significant reduction in weekly day-to-day physical activity at moderate intensities (p < 0.001), recreational activities at vigorous (p = 0.016) and moderate (p = 0.030) intensities, and travel by foot/cycle (p = 0.031). Sub-group analyses revealed that some populations became disproportionally more physically inactive and/or sedentary than others, such as those that were: living in a city (versus village), single (versus a relationship), an athlete (versus non-athlete), or earning an average household income < £25,000 (versus > £25,000). Conclusions: Now that the UK is transitioning to a state of normal living, strategies that can help individuals gradually return to physical activities, in accordance with the 2020 WHO guidelines, are of paramount importance to reducing risks to health associated with physical inactivity and sedentary behaviour.

Correction to: COVID-19: self-reported reductions in physical activity and increases in sedentary behaviour during the first national lockdown in the United Kingdom.

[This corrects the article DOI: 10.1007/s11332-022-01012-0.].

Evaluating dynamic similarity of fixed, self-selected and anatomically scaled speeds in non-linear analysis of gait during treadmill running.

OBJECTIVES: The aim of this study is to evaluate how speed affects non-linear measures of variability. Fixed and self-selected speeds were compared to an anatomically scaled speed calculated based on leg length to evaluate which provided a more reproducible result between subjects. METHODS: Sixteen subjects ran on a treadmill at a fixed, scaled and self-selected speed and at ±10% in each case. Kinematic data were collected for two minutes at 250 Hz for each trial. Sample entropy (SaEn) and maximum Lyapunov exponents (LyE) were calculated from the sagittal knee and hip joint angles to evaluate regularity of gait and local stability. These nonlinear measures were compared to evaluate the dynamic similarity of the movement in each case, and to evaluate speed as a confounding variable in non-linear analysis. RESULTS: An anatomically scaled speed shows more dynamic similarity than a fixed or self-selected speed with the lowest observed coefficient of variation for each measure. This was found to be statistically significant for both nonlinear measures of the hip (SaEn p = 0.038; LyE p = 0.040). Speed was not found to be a confounding variable in non-linear analysis of running gait of a healthy population (η2 < 0.05). CONCLUSIONS: Changes in speed by ±10% do not significantly affect stability and variability of gait for healthy participants, suggesting that they make adaptations to ensure optimal gait variability. Anatomically scaled speeds provide a more reliable methodology for both linear and non-linear analysis by providing a definitive protocol, suggesting it could replace self-selected or fixed speeds in future research.

A scoping review of non-linear analysis approaches measuring variability in gait due to lower body injury or dysfunction.

OBJECTIVES: The aim of this review is to evaluate and summarize existing literature using non-linear analysis methodology to consider variability of human movement due to lower limb injury or dysfunction. DESIGN: Scoping review. METHODS: An electronic keyword search was performed on three databases to identify appropriate research. This research was then examined for details of measures and methodology, use of control groups and general study characteristics to identify related themes. RESULTS: Fifteen papers were reviewed and synthesized. A range of conditions were studied, mainly affecting knee and ankle joints, and each using different non-linear methods and different equipment (motion capture, accelerometry, and muscle activation) to evaluate the mathematically chaotic nature of the movement and assess the variability in gait. Sample sizes and effect sizes are commonly small in these studies. CONCLUSIONS: Non-linear analysis is a potentially useful tool in both diagnosis and evaluation of injury, and this should inform future clinical processes when dealing with injury and movement variability. Despite numerous studies evaluating neurological conditions and ageing, focus on injury is limited, with notable gaps in terms of considering other joints and joint actions, so this should be a promising area of research to develop our understanding of injury and rehabilitation and how this affects gait variability.