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Updated: Jul 2, 2025

Evaluation of a Smartphone-based Human Activity Recognition System in a Daily Living Environment
Published on: December 11, 2015
[Testing an innovative approach to smartphone sensor-based technology for verification of effectiveness of home
Fanni Zsarnóczky-Dulházi1, Ádám Lelbach1,2,3, Levente Racz1
11 Magyar Testnevelési és Sporttudományi Egyetem, Kineziológia Tanszék Budapest, Alkotás u. 42-48., 1123 Magyarország.
Abstract:
Introduction: The pandemic has awakened the society to the fact, that special situations might occur when patients are not able to meet face-to-face with their healthcare professionals. In the case of physical therapy, this means exercises have to be performed mainly independently in a home environment by the patients. The lack of accuracy of the previously learned tasks decreases the quality of performance, as well as increases the risk of injuries. Objective: We introduced a solution implementing affordable and widely available devices, a smartphone and a laptop using screenshare technology. Method: In our study, four groups (experimental: young, n = 50, age 25.6 ± 3.1 years; older adults, n = 50, age 74.8 ± 9.1 years; control: young, n = 20, age 26.25 ± 3.6 years; older adults, n = 20, age 70.15 ± 5.2 years) were asked to perform squats and knee raises until pre-specified target limb angle positions. To monitor the limb movements, participants used a smartphone secured on their thigh with a goniometer application and a laptop with activated screenshare function. Results: The executions of the exercises were significantly more accurate (deviation from target angle decreased for squats, young: 7.7 to 1.7°, older: 16.4 to 7.3°; for knee-raise, young: 10.8 to 3.2°, older: 14.8 to 6.4°, respectively; p<0.05) after the technology was used. Conclusion: Our results indicate, that if subjects received numerical feedback through the laptop screen, the accuracy of the exercise execution significantly increased. We conclude that easily accessible tools and methods can serve as a basis for improvements in the effectiveness of home-based musculoskeletal rehabilitation not just for young but also for older adults. Orv Hetil. 2024; 165(7): 265–273.

