A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand,
in fulfilment of the requirements for the degree of Master of Science
in Medicine, Johannesburg, 2017 / Objective: Physical activity (PA) is recommended in the management of osteoarthritis (OA) to
reduce pain and improve function. Total volumes of PA and sedentary behaviour (SB) have been
described in people with knee OA, but detailed information about the patterns of accumulation of
PA and SB in knee OA populations is lacking. The purpose of this study was to objectively
assess the patterns of accumulation of PA and SB and to explore associations with subjectively
measured functional outcomes and quality of life in patients with knee OA.
Methods: End-stage knee OA patients (n = 87, 65 ± 8.8 (mean ± SD) years, body mass index 34.4 ± 7.8 kg/m2) with Kellgren-Lawrence-defined grade 3-4 radiographic OA, wore an
Actigraph and an activPAL accelerometer for 24 hours a day for 7 consecutive days. Total
volumes of SB, light physical activity (LPA), moderate to vigorous physical activity (MVPA),
and different bouts of SB, LPA, and MVPA were assessed. Self-report questionnaires were used
to assess patient-experienced pain, function, quality of life and activities of daily living were the
Western Ontario and McMaster Universities (WOMAC) osteoarthritis index and the Knee Injury
Osteoarthritis Outcome Score (KOOS).
Results: Of the 87 knee OA patients only 76 and 65 had complete Actigraph and activPAL data
respectively. The participants had a mean (SD) age of 65.0 (8.8) years, were mostly women and most were classified as being obese with an average BMI of 34.4 (7.8) kg/m2. The Actigraph
mean (95% CI) of awake wear time was 15.6 (15.1-16) hours/day, SB 10.9 (10.5-11.4) hours/day,
LPA 4.5 (4.1-5) hours/day and MVPA 8.2 (3.3-13) min/day. Approximately 7% of patients met
the current recommended PA guidelines. The activPAL mean (95% CI) of sitting time, standing
time, stepping time and number of steps were 9.3 (8.5 – 10.1) hours per day, 5.0 (4.4 – 5.6) hour
per day, 76.5 (66.6 – 86.3) minutes per day and 2489 (2130 – 2848) minutes per day respectively.
There were variations in the hourly patterns of movement behaviours. Participants were
significantly less sedentary between 6 am and 9 am compared to the grand mean of sedentary
time per hour over the day (p<0.01) and were significantly more sedentary per hour from 3 pm to
7 pm (p<0.05). Significant correlations were found between WOMAC pain scores and Actigraph
measured SB (r=0.277, p=0.031), LPA (r=-0.240, p=0.043), MVPA (r=-0.242. p=0.042), number
of steps (r=-0.282, p=0.020), number of breaks in bouts of SB greater than 20 minutes (r=-0.292,
x
p=0.016), average duration of breaks in SB (r=-0.277, p=0.024), average duration of MVPA
bouts (r=-0.326, p=0.012). Significant correlations were also found between WOMAC activity of
daily living scores and Actigraph measured LPA (r=-0.206, p=0.048), MVPA (r=-0.246,
p=0.029), number of steps (r=-0.286, p=0.010) and average duration of MVPA bouts (r=-0.383,
p=0.002). Significant correlations were found between WOMAC pain scores and activPAL
sitting time (r=0.029, p=0.02), and stepping time (r=-0.029, p=0.01), between self-reported
WOMAC activity of daily living score and stepping time (r=-0.309, p=0.02), between KOOS
activity of daily living score and stepping time (r=-0.276, p=0.004), and between KOOS quality
of life score and stepping time (r=-0.263, p=0.008).
Conclusion: This study describes novel detail of the patterns of activity and sedentary behaviour
in patients with knee OA. The use of two accelerometers gives a detailed account of daily activity
and the variation throughout the day, highlighting when interventions to improve activity might
be most effective. Therefore, interventions should target the long bouts of inactivity in this
population. Since even healthy populations of older adults struggle to meet current recommended
PA guidelines, it may be important to shift attention from meeting recommendations of MVPA to
creating feasible suggestions of doing more light activity and breaking more sedentary time in knee OA patients. / XL2018
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/25255 |
| Date | January 2017 |
| Creators | Kaoje, Yusuf Suleiman |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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