Background Many physical examination (PE) maneuvers exist to assess knee function, none of which are specific to knee osteoarthritis (KOA). disease duration was 8.4?years (SD?=?10.1) and 27 participants had varus knee alignment. Mean WOMAC pain and function scores were 211 (SD?=?113) and 709 (SD?=?394), respectively. Weakness was present in major hip and knee muscles. Seventy-nine participants had a positive Elys, 65 a positive Waldron and 49 a positive Grind. Mean 6-min walk was 404?m (SD?=?83) and mean Berg Balance was 53 (SD?=?4). Regression analysis identified positive findings on 5 special assessments (P?0.05) as indicative of poorer 6?min walk. Positive Apleys was associated (P?0.05) with slower 20?m walk and a positive Ober with poorer sense of balance scores (P?0.05). Conclusions Diminished hip muscle strength and flexibility, and patella dysfunction were prevalent in these adults with symptomatic KOA. Results of functional performance tests suggest balance and walking ability are impaired and are associated with PE findings of muscle length imbalance, hip muscle weakness and patella dysfunction. None of the PE steps were associated buy A 922500 with self-reported function. Therefore, performance-based test results may Cd14 be more useful in informing rehabilitation interventions. Keywords: Knee osteoarthritis, Physical examination, Performance-based function, Self-reported function Background Symptomatic knee osteoarthritis (KOA) is one of the ten most disabling diseases in developed countries affecting an estimated 19?% of women and 14?% of men in the United States over 45?years . KOA results from progressive destruction of articular cartilage, ligaments, and joint capsule, synovial membrane inflammation and subchondral bone calcification . Pain from knee and muscle impairments, buy A 922500 mainly the quadriceps and hamstrings, are associated with KOA . Other common symptoms of KOA include crepitus, reduced joint motion (both range of motion and arthrokinematic motion quality), impaired proprioception, joint line and periarticular tenderness on palpation and moderate synovitis [2, 4C6]. These symptoms may produce impairments in body functions, activity limitations and participation restrictions . In 2013, Osteoarthritis Research Society International (OARSI) provided a set of recommended performance-based steps to assess physical function in adults with KOA. These steps include assessments of aerobic conditioning, walking speed, functional mobility and lower extremity strength . Radiographic findings in the absence of a physical examination, are not very useful in identifying the source of pain in symptomatic KOA [8, 9]. Therefore, clinicians also rely on the patient history, physical examination (PE) procedures and special assessments to assist in clinical decision-making. Special assessments of muscle flexibility are used to assess muscle length and flexibility e.g., Elys for rectus femoris and Ober for the iliotibial band . Ligamentous assessments are conducted to examine knee joint integrity/stability, buy A 922500 as a proxy for changes in knee biomechanics, secondary to muscular tightness or changes in buy A 922500 lower limb alignment . Despite the common use of these physical examination procedures in clinical practice, the psychometric properties of these procedures are poor [10, 11]. The poor association between PE findings and self-reported function and performance-based function may be related, in part, to central sensitization in arthritis, which can contribute to several of the positive findings. Performance based examinations are additional methods used to assess physical function and provide complementary information regarding KOA-associated disability . Thus, research into optimal clinical examination sequence and composition is usually lacking and necessary given time constraints in clinical practice. While studies have examined the association between PE findings and self-reported function in adults with knee pain  and in those with KOA [14C17], few studies have examined the association between PE findings and performance-based function in adults with symptomatic KOA . This study provides a detailed clinical description of adults with symptomatic KOA and aims to determine the relative contribution of PE results primarily on performance-based function, adjusting for age and gender. Secondarily, we aimed to examine the contribution of PE findings on self-reported function (Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain, WOMAC function). It was hypothesized that special tests of pain provocation, and muscle flexibility would more strongly correlate with functional performance than self-reported function and pain. Methods This cross-sectional study is a secondary analysis buy A 922500 of data from a prospective randomized clinical trial evaluating the effectiveness and cost-effectiveness of Tai Chi versus a physical-therapy regimen in adults with symptomatic and radiographically confirmed KOA [18, 19]. Institutional Human Subjects approval was obtained for this secondary study. We included the subset of 87 participants from the primary study who.