TY - JOUR
T1 - Sit-to-Stand 3 months after unilateral total knee arthroplasty
T2 - Comparison of self-selected and constrained conditions
AU - Farquhar, Sara J.
AU - Kaufman, Kenton R.
AU - Snyder-Mackler, Lynn
N1 - Funding Information:
This study was conducted in the Department of Physical Therapy at the University of Delaware. Funding was provided by the National Institutes of Health (R01-HD041055, T32-HD07490, S10-RR022396). We would like to thank First State Orthopaedics, specifically Drs. Alex Bodenstab, William Newcomb, and Leo Raisis for their patient referrals. We wish to thank Ryan Mizner for initial recruitment of some of the participants, and Yuri Yoshida for assistance with data collection.
Funding Information:
SJF and LSM acknowledge financial support from the National Institutes of Health (NIH T32 HD7490-09, NIH R01 HD041055-01). KRK did not receive funding or financial support for this study. The authors of this manuscript receive no financial benefit from the publication of these findings.
PY - 2009/8
Y1 - 2009/8
N2 - After unilateral total knee arthroplasty (TKA), rehabilitation specialists often constrain knee angles or foot positions during sit-to-stand, to encourage increased weight bearing through the operated limb. Biomechanical studies often constrain limb position during sit-to-stand in an effort to reduce variability. Differences between self-selecting or constraining position are unknown in persons after TKA. Twenty-six subjects with unilateral TKA participated in motion analysis. Subjects performed the sit-to-stand using a self-selected position (ssSTS); next, trials were collected in a constrained condition (ccSTS), where both knees were positioned with the tibia vertical, perpendicular to the floor. Repeated measures ANOVA (limb × condition) assessed differences between limbs and between conditions. Subjects used greater hip flexion bilaterally during ccSTS (91°) compared to ssSTS (87°; p = 0.001) and knee flexion on the non-operated limb was greater during ssSTS (84°) compared to ccSTS (82°; p = 0.018). The ccSTS resulted in larger extensor moments on the non-operated limb at the hip (ssSTS -0.473, ccSTS -0.521; p = 0.021) and knee (ssSTS -0.431, ccSTS -0.457; p = 0.001) compared to the operated limb. The ccSTS exacerbated the asymmetries at the hip and knee compared to ssSTS, and did not improve use of the operated limb. Reliance on the non-operated limb may put them at risk for progression of osteoarthritis in other joints of the lower extremities.
AB - After unilateral total knee arthroplasty (TKA), rehabilitation specialists often constrain knee angles or foot positions during sit-to-stand, to encourage increased weight bearing through the operated limb. Biomechanical studies often constrain limb position during sit-to-stand in an effort to reduce variability. Differences between self-selecting or constraining position are unknown in persons after TKA. Twenty-six subjects with unilateral TKA participated in motion analysis. Subjects performed the sit-to-stand using a self-selected position (ssSTS); next, trials were collected in a constrained condition (ccSTS), where both knees were positioned with the tibia vertical, perpendicular to the floor. Repeated measures ANOVA (limb × condition) assessed differences between limbs and between conditions. Subjects used greater hip flexion bilaterally during ccSTS (91°) compared to ssSTS (87°; p = 0.001) and knee flexion on the non-operated limb was greater during ssSTS (84°) compared to ccSTS (82°; p = 0.018). The ccSTS resulted in larger extensor moments on the non-operated limb at the hip (ssSTS -0.473, ccSTS -0.521; p = 0.021) and knee (ssSTS -0.431, ccSTS -0.457; p = 0.001) compared to the operated limb. The ccSTS exacerbated the asymmetries at the hip and knee compared to ssSTS, and did not improve use of the operated limb. Reliance on the non-operated limb may put them at risk for progression of osteoarthritis in other joints of the lower extremities.
KW - Altered movement pattern
KW - Sit-to-stand
KW - Total knee arthroplasty
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U2 - 10.1016/j.gaitpost.2009.04.007
DO - 10.1016/j.gaitpost.2009.04.007
M3 - Article
C2 - 19473843
AN - SCOPUS:67649599114
SN - 0966-6362
VL - 30
SP - 187
EP - 191
JO - Gait and Posture
JF - Gait and Posture
IS - 2
ER -