Analysis of knee flexion characteristics and how they alter with the onset of knee osteoarthritis: a case control study

Background: The purpose of this study was to examine the differences in gait profile between patients with knee osteoarthritis (OA) and healthy control and to create motion characteristics that will differentiate between them. Methods: Twenty three patients diagnosed with knee OA and 21 healthy matched controls underwent a gait test using a sensor system (gaitWALK). Gait parameters evaluated were: stride duration, knee flexion range of motion (ROM) in swing and stance. T-Test was used to evaluate significant differences between groups (P < 0.05). Results: Patients with knee OA had significant lower knee flexion ROM (10.3 degrees +/- 4.0 degrees) during stance than matched controls (18.0 degrees +/- 4.0 degrees) (p < 0.001). Patients with knee OA had significant lower knee flexion ROM (54.8 degrees +/- 5.5 degrees) during swing than matched controls (61.2 degrees +/- 6.1) (p = 0.003). Patients with knee OA also had longer stride duration (1.12 s +/- 0.09 s) than matched controls (1.06 s +/- 0.11 s), but this was not statistically significant (p = 0.073). Motion characteristics differentiate between a patient with knee OA and a healthy one with a sensitivity of 0.952 and a specificity of 0.783. Conclusions: Significant differences were found in the gait profile of patients with knee OA compared to matched control and motion characteristics were identified. This test might help clinicians identify and evaluate a knee problem in a simple gait test.