BACKGROUND
Real-world walking speed is being proposed as the sixth vital sign to track functional health; this requires consideration of how the context of activity affects the individual. For example, as it gets colder outside healthy adults walk faster and increase their cadence (steps/min). Environmental factors (weather conditions, time of year, time of day) and the individual (disease-group, gender, height, BMI) may have a varied impact on walking speed across disease cohorts.
OBJECTIVE
The aim of the paper is to examine the relationship between temperature and wind speed with measures of outdoor walking speed (cadence) across disease groups and healthy adult controls. Expected differences between disease groups and healthy controls were expected to be found.
METHODS
As a part of a technical validation study assessing worn mobility trackers (Mobilise-D), participants were asked to carry a smartphone with an installed tracking app recording GPS location, step activity and local temperature and wind speed, of walking bouts for seven consecutive days. A total of 57 participants were assessed included: 16 healthy adults, 12 patients with Multiple Sclerosis, 17 patients with Chronic Obstructive Pulmonary disease and 12 with Parkinson’s disease.
RESULTS
Pearson and Spearman Rank correlation coefficients were obtained for associations between hourly temperature and wind speed against hourly measurements of cadence and physical activity. Temperature and wind speed were found to be positively correlated with cadence (CI: -.437, -.228). Fisher’s r groupwise comparison established significant differences for associations of weather and mobility between health adults and COPD (p <.001), MS (p =.032), and PD (p = .007). The opposite effect of temperature on physical activity was observed in MS compared against COPD, PD and HA groups.
CONCLUSIONS
Mobility impaired disease groups are affected by the weather in a dissimilar pattern to that of healthy adults. This should be accounted for when measuring digital mobility outcomes of various patient groups. Smartphone apps for real world cadence appear to be very similar to those recorded by wearable sensors for both healthy adults and disease groups