Diferencias asociadas a la edad en las propiedades mecánicas y funcionales de la musculatura flexo-extensora de rodilla

Introduction and Objective. The decline in muscle quality (MQ) with aging is associated with increased morbidity and mortality. Therefore, characterizing MQ in older adults (OA) is essential. The objective of this study was to characterize and compare MQ indicators of knee flexor-extensor muscles across different age groups. Methodology. A total of 66 volunteers of both sexes were divided into three groups: young adults (22.1 ± 1.6 years), adults (49.9 ± 8.3 years), and older adults (71.0 ± 6.4 years). Maximum radial displacement (Dm) and contraction time (Tc) of the Rectus Femoris (RF) and Biceps Femoris (BF) were assessed, along with dynamometric variables of knee flexor-extensor isometric strength and power. Group differences were analyzed using ANOVA, and correlations between tensiomyographic and dynamometric variables were examined. Results. Aging was associated with a decrease (p < 0.05) in isometric strength and power for both knee extension and flexion, and with a significant increase (p < 0.05) in RF Tc and a tendency to increase in BF Tc. Dm values of both muscles did not show significant differences (p > 0.05) between groups. For knee extension, a weak negative correlation (p < 0.05) was observed between both strength measures and RF Tc, and a weak positive correlation between these measures and RF Dm. For knee flexion, weak negative correlations (p < 0.05) were found between both strength modalities and BF Tc, with no correlations with BF Dm. Conclusions. Tensiomyographic variables, particularly Dm, do not appear to be sensitive indicators for detecting age-related declines in MQ when analyzed in isolation. Additional indicators may be necessary to improve the accuracy of MQ assessment in older adults.