Biomedical subjects

Rob C van Lummel

Publications and source records attributed to Rob C van Lummel.

4 recordsLinked to original sources

PubMed2006

Self-reported physical functioning was more influenced by pain than performance-based physical functioning in knee-osteoarthritis patients.

BACKGROUND AND OBJECTIVES: To test the hypothesis that self-reported physical functioning is more influenced by pain than performance-based physical functioning. METHODS: 163 knee-osteoarthritis patients completed the performance-based DynaPort KneeTest (DPKT), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and SF-36 (self-report measures of pain and physical functioning) before, 3, 6, and 12 months after knee replacement. RESULTS: Correlations between (two) self-reported measures of functioning and (two) pain measures were higher (0.57-0.74) than correlations between the performance-based measure of functioning and the two pain measures (0.20 and 0.26). In factor analysis, WOMAC and SF-36 pain and physical functioning subscores loaded on the first factor (eigenvalue 3.2), while DPKT KneeScore2 loaded on the second factor (eigenvalue 0.92). Before surgery, correlations between performance-based and self-reported physical functioning were higher in patients with less pain (0.43) compared to patients with more pain (0.17), for the WOMAC (as expected), but not for the SF-36. After surgery, when the pain had diminished, the correlations between performance-based and self-reported physical functioning were higher, especially for the WOMAC. CONCLUSIONS: Our hypothesis was convincingly supported by the results of the WOMAC, and somewhat less by the results of the SF-36. We consider this as evidence for a lack of content validity of the WOMAC.

Activities of Daily Living↗

PubMed2005

Reproducibility and validity of the DynaPort KneeTest.

OBJECTIVE: To determine the reproducibility and validity of the DynaPort KneeTest, a performance-based test that measures quality of movement of patients undergoing total knee replacement (TKR). METHODS: A total of 92 patients with osteoarthritis (OA) of the knee performed the KneeTest twice on the same day; 94 healthy controls performed the KneeTest once. During the test, 29 activities were performed with accelerometers attached to the body. Relevant functional parameters were extracted from the accelerometers. A selection of parameters was used to calculate activity scores, based on the ability of parameters to discriminate between patients and controls (regression analyses). Based on internal consistency analyses (Cronbach's alpha), redundant activities were removed. Four cluster scores and a total KneeScore were calculated from the remaining activity scores. Reproducibility and validity of the cluster scores and the total KneeScore 2 were assessed. RESULTS: Based on internal consistency analyses, the test was reduced to 23 activities. Inter- and intraobserver reliability using intraclass correlation coefficients were 0.90 (0.83-0.94) and 0.95 (0.83-0.98), respectively. Limits of inter- and intraobserver agreement were -8.3 to 11.3 and -4.2 to 9.0. Construct validity was confirmed by expected correlations with the Western Ontario and McMaster University Osteoarthritis Index physical functioning (0.55), Medical Outcomes Study Short Form-36 Health Survey physical functioning (0.62), and Knee Society Score function (0.64). CONCLUSION: The KneeTest is a useful performance-based measure for research in patients with knee OA undergoing TKR, with good reliability and validity. Further research is required to improve its usefulness for clinical practice.

Aged↗

PubMed2005

The accuracy of measuring the kinematics of rising from a chair with accelerometers and gyroscopes.

The purpose of this study was to assess the accuracy of measuring angle and angular velocity of the upper body and upper leg during rising from a chair with accelerometers, using low-pass filtering of the accelerometer signal. Also, the improvement in accuracy of the measurement with additional use of high-pass filtered gyroscopes was assessed. Two uni-axial accelerometers and one gyroscope (DynaPort) per segment were used to measure angles and angular velocities of upper body and upper leg. Calculated angles and angular velocities were compared to a high-quality optical motion analysis system (Optotrak), using root mean squared error (RMS) and correlation coefficient (r) as parameters. The results for the sensors showed that two uni-axial accelerometers give a reasonable accurate measurement of the kinematics of rising from a chair (RMS = 2.9, 3.5, and 2.6 degrees for angle and RMS = 9.4, 18.4, and 11.5 degrees /s for angular velocity for thorax, pelvis, and upper leg, respectively). Additional use of gyroscopes improved the accuracy significantly (RMS = 0.8, 1.1, and 1.7 degrees for angle and RMS = 2.6, 4.0 and 4.9 degrees /s for angular velocity for thorax, pelvis and upper leg, respectively). The low-pass Butterworth filter had optimal cut-off frequencies of 1.05, 1.3, and 1.05 for thorax, pelvis, and upper leg, respectively. For the combined signal, the optimal cut-off frequencies were 0.18, 0.2, and 0,38 for thorax, pelvis and upper leg, respectively. The filters showed no subject specificity. This study provides an accurate, inexpensive and simple method to measure the kinematics of movements similar to rising from a chair.

Acceleration↗

PubMed2005

Construct validity of the DynaPort KneeTest: a comparison with observations of physical therapists.

OBJECTIVE: To assess the construct validity of the DynaPort KneeTest (KneeTest), which is a performance-based test to assess functioning of patients with knee osteoarthritis (OA). Scores on the KneeTest (KneeScore) were compared with observations of physical therapists of the patients' functional disability. The reliability of these observations was also assessed. METHOD: Twelve physical therapists received identical video tapes showing the performance of 33 patients on the KneeTest. Each physical therapist rated the functional disability of each patient, performing the 23 activities of the KneeTest, on 23 Visual Analogue Scales (VAS(activity)). The 23 VAS(activity) scores were averaged into a VAS(average) score. At the end of the test, an overall rating for the general performance of the patient was given on a VAS(overall). Inter-observer Reliability was assessed for the VAS(activity) scores, VAS(average), and the VAS(overall). RESULTS: Inter-observer reliability of the VAS(average) was higher (ICC 0.85, 95% CI 0.74-0.92) than the VAS(overall) (ICC 0.65, 95% CI 0.51-0.77). The correlation between the KneeScore and the VAS(average), averaged over the 12 physiotherapists, was 0.86. CONCLUSION: The construct validity of the KneeTest was supported by the strong correlation with the ratings of the patients' disability by physical therapists. Given these findings and the high test-retest reliability of the KneeTest that was found in our previous study, we conclude that the KneeTest is a valid measure for assessing functioning in orthopedic and physical therapy research in patients with knee-OA before and after total knee replacement. Longitudinal validity has to be evaluated yet.

Activities of Daily Living↗