Características biomecânicas do tronco e membro inferior durante tarefas funcionais e da função dos músculos do quadril e joelho em indivíduos com osteoartrite patelofemoral

Abstract

The main objective of this PhD dissertation was to compare the biomechanical characteristics of the trunk, pelvis and lower limb during functional tasks, and muscle function of the hip and knee between individuals with patellofemoral osteoarthritis (PFOA) and controls. This research consisted of four studies. Study I was a systematic review conducted to synthesize evidence on differences in kinematic and kinetic variables during functional tasks, and muscle function in individuals with PFOA compared to controls. Eleven studies were included. The level of evidence was very low for knee flexion angle during the walking task and for isometric strength of the hip abductor and external hip rotator muscles. The focus of Study II was to compare hip and knee muscle capacity between individuals with and without isolated PFOA and evaluate the impact of PFOA on pain, stiffness and physical functioning. Muscle capacity of the hip and knee was evaluated using an isokinetic dynamometer. The isokinetic variables used in the statistical analysis were peak torque, total work and average power. Pain, stiffness and physical functioning were assessed using questionnaires. Twenty-six individuals participated in the study (13 with PFOA and 13 controls). The PFOA group had impairment of the muscular capacity of the knee extension and flexion in the concentric and eccentric mode, and of the muscular capacity of extension, abduction, adduction and internal rotation of the hip in the eccentric mode. The PFOA group had higher levels of pain, stiffness and self-reported compromised physical functioning compared to controls. In Studies III and I, the analysis of trunk, pelvis, hip and knee kinematics during the single-leg squat was performed using a three-dimensional (3D) motion analysis system and isometric hip torque was determined using a handheld dynamometer. Trunk, pelvis and lower limb kinematics were evaluated only on the frontal plane in Study III, whereas kinematics was evaluated on all three planes in Study IV. Moreover, only isometric hip abductor torque was evaluated in Study III, whereas isometric hip extensor and external rotator torques were also evaluated in Study IV. In both studies, individuals with isolated PFOA had greater hip adduction at 45° and 60° of knee flexion in the descending and ascending phases of the single-leg squat. In Study IV, individuals with isolated PFOA also exhibited greater hip adduction at 30° of knee flexion in the descending phase of the single leg-squat. No significant differences were found between groups for trunk flexion and inclination, pelvic elevation, hip flexion and internal rotation or knee abduction at angles of 30°, 45° and 60° of knee flexion in the both phases of the single-leg squat. The PFOA group had lower isometric hip abductor torque in both studies and lower isometric hip extensor and external rotator torque in Study IV. The results of this PhD dissertation show that individuals with PFOA may have altered kinematics during functional tasks as well as lower hip and knee muscle capacity and report higher levels of pain, stiffness and impairment of physical functioning compared to controls.