TY - JOUR
T1 - Impaired postural balance in the morning in patients with knee osteoarthritis
AU - Sørensen, Rasmus Reinholdt
AU - Jørgensen, Martin Grønbech
AU - Rasmussen, Sten
AU - Skou, Søren Thorgaard
PY - 2014/4
Y1 - 2014/4
N2 - Postural balance (PB) is frequently used as an outcome measure in clinical and research settings when assessing patients with knee osteoarthritis (OA). Pain and stiffness is known to affect PB, and is elevated in the morning and evening in OA patients. The aim of this study was to explore if time-of-day affects PB control in knee OA patients.Centre Of Pressure (COP) excursion was measured (100Hz) by force plate technique at selected time-points (9.00 a.m., 12.30 p.m. and 4.00 p.m.) during a single day in 32 knee OA patients aged 66.0 (10.3) years. A rigorous protocol was followed to ensure comparable testing conditions across time-points. PB control was quantified by the COP variables: velocity moment (mm2/s), total sway area (mm2), total sway length (mm) and confidence ellipse area (mm2).A two-way mixed-effects model showed that PB significantly improved between 9.00 a.m. and 12.30 p.m. in three out of four COP variables. The observed improvement was 11.9% (p= 0.011) for velocity moment, 12.2% (p= 0.011) for total sway area and 9.4% (p< 0.001) for total sway length.PB appears to be impaired in the morning relative to midday in knee OA patients. Thus, it is recommended that time of assessment is standardized between sessions when assessing PB in clinical and research settings in knee OA patients.
AB - Postural balance (PB) is frequently used as an outcome measure in clinical and research settings when assessing patients with knee osteoarthritis (OA). Pain and stiffness is known to affect PB, and is elevated in the morning and evening in OA patients. The aim of this study was to explore if time-of-day affects PB control in knee OA patients.Centre Of Pressure (COP) excursion was measured (100Hz) by force plate technique at selected time-points (9.00 a.m., 12.30 p.m. and 4.00 p.m.) during a single day in 32 knee OA patients aged 66.0 (10.3) years. A rigorous protocol was followed to ensure comparable testing conditions across time-points. PB control was quantified by the COP variables: velocity moment (mm2/s), total sway area (mm2), total sway length (mm) and confidence ellipse area (mm2).A two-way mixed-effects model showed that PB significantly improved between 9.00 a.m. and 12.30 p.m. in three out of four COP variables. The observed improvement was 11.9% (p= 0.011) for velocity moment, 12.2% (p= 0.011) for total sway area and 9.4% (p< 0.001) for total sway length.PB appears to be impaired in the morning relative to midday in knee OA patients. Thus, it is recommended that time of assessment is standardized between sessions when assessing PB in clinical and research settings in knee OA patients.
KW - Centre of pressure
KW - Force plate analysis
KW - Knee osteoarthritis
KW - Postural balance
KW - Time-of-day
UR - http://www.scopus.com/inward/record.url?scp=84897112442&partnerID=8YFLogxK
U2 - 10.1016/j.gaitpost.2014.01.002
DO - 10.1016/j.gaitpost.2014.01.002
M3 - Article
C2 - 24480548
AN - SCOPUS:84897112442
VL - 39
SP - 1040
EP - 1044
JO - Gait and Posture
JF - Gait and Posture
SN - 0966-6362
IS - 4
ER -