Duration and frequency of every day activities in total hip patients

Journal
Journal of biomechanics  
Volume
34
Issue
7
Start Page
873
End Page
881
Citation
Journal of Biomechanics 34 (7): 873-881 (2001)
Publisher DOI
10.1016/S0021-9290(01)00035-5
Scopus ID
2-s2.0-0034989649
Publisher
Elsevier Science
Little knowledge about frequency and duration of daily activities in patients after total hip arthroplasty is available. Such information is required for the definition of realistic load collectives for pre-clinical testing of prostheses. It could also be helpful for the quantitative evaluation of surgery outcome with different prosthesis types. The purpose of this study was to develop and apply a system for the determination of frequency and duration of patient activities in their habitual environment and to compare the results to a clinical outcome score (Harris hip score).A portable activity monitoring system (weight 1.6kg including batteries) was designed using a Palmtop computer, 2 inclination sensors for the thigh and calf and one goniometer positioned at the knee joint. An algorithm was developed to identify frequency and duration of the activities lying, sitting, standing, walking and stair climbing from the signals of the 3 sensors. 42 patients participated in the study and were equipped with the system in the morning at their home. Datasets of 31 patients (age 62.5±11.5y) covered more than 6h (9.8±1.6h) and were included in the analysis. Prosthesis specific data as well as the Harris hip score were collected.The most frequent patient activity was sitting (44.3% of the time), followed by standing (24.5%), walking (10.2%), lying (5.8%) and stair climbing (0.4%). The median number of steps/stairs was 6048/164. The number of step cycles representing one year in vivo use should, consequently, be increaesed to 1.1million. The Harris hip score (91.4±9.8) correlated significantly with the number of stairs (r2=0.26, p=0.003) and showed a positive tendency with the number of steps per day. No differences in activity levels between prosthesis specific factors were found.
Subjects
Activity monitoring
Harris hip score
Patient activities
Total hip arthroplasty
DDC Class
610: Medicine, Health