Análise da cinemática e do padrão de ativação muscular durante a marcha de idosas assintomáticas e com osteoartrite de joelhos

Abstract

Knee osteoarthritis (OA) is the most commom cause of disability among elderly. Understanding how function is affected by pathology may be critical in designing effective interventions for preventing disability. In this way, the gait study is especially relevant because the great importance of this activity to these subjects function. The purposes of this study were: (a) investigate knee, hip and ankle kinematic alterations during gait of elderly women with knee OA when compared with asymptomatic elderly women; (b) compare muscle activation patterns during gait between elderly women with knee OA and asymptomatic elderly women; (c) compare quadriceps and hamstrings muscles work for body weight; (d) investigate the association between quadriceps strength and knee kinematics in the load response phase. The sample of this study was composed by 21 elderly women with knee OA (71,43 + 4,14 years old) and 21 asymptomatic elderly women (71,38 + 4,09 years old). Kinematics data were obtained during usual gait of the subjects by a motion analysis system. Intensity and duration of vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius and soleus muscles activity during gait was assessed by surface electromiography. The isokinetic dynamometry was used to assess quadriceps and hamstring work for body weight. ANOVA test was used to determine differences between groups and the correlations were calculated by Pearson coefficient. The level of significance was set at =0,05. Elderly with knee osteoarthritis demonstrated less knee flexion peak during initial swing phase (p=0,003), less knee flexion excursion during weight acceptance (p=0,019) and stance (p=0,046) and less hip extension excursion during stance (p=0,007). There were no significant differences between groups for muscle activation patterns during gait and quadriceps and hamstrings strength. In summary, the gait of elderly women with knee osteoarthritis demonstrated kinematics alterations that were not limited to the knee, affecting either the hip. Moreover, there were no differences in muscle function between groups, suggesting that gait alterations can occur without strength decrease.