Validation of Physical Performance Tests in Individuals with Advanced Knee Osteoarthritis

Abstract

Background Individuals with advanced osteoarthritis (OA) of the knee experience significant impairments in balance and in essential physical functions such as walking and rising from a chair. There is limited evidence on valid outcome measures to capture these impairments. Questions/Purposes We sought to examine the construct validity of three physical performance measures in patients with advanced knee OA: a gait speed (GS) test, the Short Physical Performance Battery (SPPB), and the Timed Up and Go (TUG) test. Methods We designed a cross-sectional clinical measurement study in which patients with advanced knee OA completed two self-reported measures: the Knee Injury and Osteoarthritis Outcome Score—Physical Function Shortform (KOOS-PS) and a four-part numeric pain rating scale (Q-NPRS). They were also administered the GS test, TUG test, and SPPB. Convergent and divergent construct validity were assessed by examining relationships between the GS test, the SPPB, the TUG test, the KOOS-PS, and the Q-NPRS and calculating Pearson correlation coefficients (r). The scores for the GS, TUG test, and SPPB were compared with established normative values for age-matched healthy controls. Results Forty-four subjects (mean age, 66.9 ± 8.1 years) participated in the study. The GS test showed low concordance with the SPPB component tests and the TUG test. The relationships between the physical performance measures and the self-reported measures were low. The scores for the GS test, TUG test, and SPPB in our sample were significantly worse when compared with age-matched normative values, indicating impairments in physical performance. Conclusion These results advance the understanding of the validity of the GS test, TUG test, and SPPB in demonstrating the impairments in physical performance that patients with advanced knee OA experience in walking, balancing, and rising from a chair. Future research should examine the reproducibility and responsiveness of the GS test, TUG test, and SPPB in patients with advanced knee OA, in order to facilitate the integration of these measures into clinical practice.

Postural Stability and Proprioception Abnormalities in Patients with Knee Osteoarthritis

“…In general, clinical-functional scores of patients in the present study are not different from values available in other studies on knee OA patients for KSS [37][38][39] and for SPPB [40][41][42]. Also, knee OA as radiologically measured by means of the Kellgren-Lawrence score resulted in correlation to the average Stability Index in the open eyes trial, suggesting that a worse functional performance is present in more severe radiological OA.…”

Measurement properties of performance-based measures to assess physical function in knee osteoarthritis: A systematic review

“…Six multi-activity measures were the SPPB, 34 the Performance Tests Measures (PerF), 30 Physical Activity Restrictions (PAR), 32 Timed Assessment, 11 Aggregated Locomotor Function (ALR), 33 and Iowa Level of Assistance Scale (ILAS). 31…”

“…When applied in mild to moderate patients, it showed sufficient reliability, 17 and when used in ES or postoperative patients, it showed sufficient hypothesis testing and responsiveness. 23,34 However, this test may not be sensitive enough to reveal early signs of functional decline. 54 Other tests and multi-activity measures…”

Association of Self-Reported Functional Limitations among a National Community-Based Sample of Older United States Adults with Pain: A Cross-Sectional Study

“…Further investigation may be needed in this area due to research findings with mixed results. For instance, a prior study found that among older people, both self-reported and objective measures of physical functioning were associated with disability onset [ 39 ], whereas another study among people with knee osteoarthritis found physical performance test measures correlated poorly with self-reported measures [ 40 ]. For the last significant need factor, total number of prevalent chronic health conditions, since having more chronic conditions was associated with reporting a functional limitation, this suggests the potential benefit for healthcare providers to recommend older adults with five or more chronic conditions to undergo physical performance tests.…”