gms | German Medical Science

Objectives: Restoring mobility and functional independence after surgery is a main goal of orthogeriatric co-management. Current data show that the frequency of future falls and the associated impairments can be reduced by recognizing mobility restrictions at an early stage and minimizing risk factors. For that, the use of accelerometer-based activity trackers has increased in recent years. Current studies rate postoperative mobility as generally very low [1]. The aim of this study was to determine basic preoperative comparison values of mobility based on the daily number of steps in the healthy population.

Methods: 20 participants over 65 years of age and 26 participants under 65 years of age wore an activPAL motion sensor (PAL Technologies Ltd., UK) on their thigh for 24 hours for seven days to record the number of daily steps. In addition, the Parker Mobility Score (PMS) and Barthel Index were used to subjectively assess mobility and activities. Statistical analysis was performed using GraphPad Prism 9 (GraphPad Software, La Jolla, USA). Results are expressed as mean ± standard error (SD). Significances were calculated using a Man-Whitney-U test or t-Test. A value of p < 0.05 was considered significant.

Results and conclusion: Participants under 65 years of age achieved a mean PMS of 9.0, while participants over 65 years of age had a mean PMS of 8.5. Participants under 65 years of age scored a mean Barthel Index of 100.0, participants over 65 years of age had a mean Barthel Index of 95.5. People under 65 years of age achieved a significantly higher number of steps per day (9,973) compared to people over 65 years of age (6,897). Additional information are listed in Table 1 [Tab. 1].

Data shows that healthy adults walk between 4,000 and 18,000 steps per day on average. In healthy older adults, it averages 2,000 to 9,000 steps per day [2]. The data now measured agree with the previous literature. People over 65 years have a significant decrease in daily step count compared to younger people.

A recently published study evaluated postoperative mobility in orthogeriatric patients using a hip-worn accelerometer (actibelt^®). Postoperative mobility was very low, ranging from 102.7 to 413.5 daily steps [1]. Davenport et al. found comparable results in their study of a daily step count of 36 in patients after hip surgery [3]. With an average of 6,897 measured steps per day in the healthy elderly population, there is now a massive discrepancy between preoperative and postoperative mobility. Intensive remobilization programs should therefore be implemented in the clinical setting to return to initial mobility.

A thigh-worn motion sensor proved to be a practicable wearable for the continuous recording of mobility in the subjects' usual environment over a period of 7 days. The motion sensor and also the data extraction algorithm must be adjusted for each patient in order to measure realistic mobilization and detect long-term changes including behavior and activities.