FUNCTION AND STRENGTH OF PHYSICALLY ACTIVE INDIVIDUALS WITH A UNILATERAL, SINGLE-AXIS KNEE REPLACEMENT

INTRODUCTION: Only recently could total knee replacement (TKR) individuals participate in many activities that place high stress on the knee region, e.g., golf. To enhance physical functioning, TKR components must be able to provide optimal leverage for the quadriceps to generate extensor torque, a-p stability when the cruciate ligaments are sacrificed, and varusvalgus stability via adequate medial and lateral collateral tension throughout the (Range of Motion) ROM. The use of a single flexion/extension (F/E) axis TKR design rather than a multiaxial TKR design has been theorized to accomplish these goals. Therefore, for this work in progress, it was of interest to determine for physically active individuals if the strength and function of the limb with a unilateral, single-axis TKR would be different to that of the intact limb

Biomechanical differences exhibited during sit-to-stand between total knee arthroplasty designs of varying radii

The purpose of the study was to investigate the influence of the mechanical differences between a single-radius total knee arthroplasty (SR TKA) and a multi-radius (MR) TKA design on the functional performance during a sit-to-stand movement. Three-dimensional kinematics and electromyography for selected knee flexor and extensor muscles were obtained for 16 (8 SR and 8 MR) unilateral, posterior-stabilized TKA participants. Compared to the SR group, the MR group demonstrated compensatory adaptations, with increases in performance time, trunk flexion displacement and velocity, and knee extensor electromyography; and greater relative hamstring co-activation of the MR limbs was needed to increase joint stability. An initial knee abduction displacement was exhibited by more MR than SR participants. In conclusion, SR TKA provides functional benefits to patients