title: Analysis of rising from a chair after total knee arthroplasty.
abstract: The relationship between the range of motion following total knee arthroplasty (TKA) and the height of chairs when rising from a seated position was analyzed. Forty-six TKA subjects were evaluated; 16 had osteoarthritis, 30 had rheumatoid arthritis. Subjects were divided into two groups based on their degree of knee flexion (average: 96.0 degrees; range: 75 degrees to 135 degrees; group 1 contained 24 subjects with < 100 degrees of flexion and group 2 contained 22 subjects with > 100 degrees of flexion) in order to evaluate the acceptable knee flexion angle required for comfortably rising from a chair. To evaluate the flexion-extension angle of the knee and hip joints, three goniometers, a large reaction force plate, and a switch sensor on the chair surface to detect the initiation of rising were used. One chair had a height equal to the subjects' lower leg length, while the height of the second chair was 120% of the subjects' lower leg length. Analysis showed that TKA patients with less knee flexion (< 100 degrees) required a high angular velocity of the hip and excessive swing velocity to lift the trunk forward than did those with a larger degree of knee flexion (> 100 degrees). We concluded that a minimum of 100 degrees of postoperative flexion is desired and that a higher chair is more suitable for TKA patients.
authors.affiliation: Department of Orthopaedic Surgery, Gifu University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Itokazu
authors.forename: S
authors.initials: S
authors.lastname: Uemura
authors.forename: T
authors.initials: T
authors.lastname: Aoki
authors.forename: T
authors.initials: T
authors.lastname: Takatsu
mesh_terms: D000203:Activities of Daily Living; D001172:Arthritis, Rheumatoid / Q000503:physiopathology / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D005500:Follow-Up Studies; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D010003:Osteoarthritis / Q000503:physiopathology / Q000601:surgery; D011184:Postoperative Period; D016059:Range of Motion, Articular