Effects of age and a balance training with vibrating rod in motor response and biomechanical parameters of muscle strength and power of the hip, knee and ankle in older women

Abstract

The vibrating rod training has shown positive effects in young individuals, in the strength, power and muscle activation, however, studies investigating these effects in older individuals are scarce. Therefore, the aim of this study is to analyze the effect of a training protocol with vibrating rod on biomechanical parameters of strength, power and muscle activation in physically active older women. For this purpose, will be recruited for the study 40 women divided into two groups: Elderly Group (EG, 60 to 85 years) and Young Group (YG, 18 to 25 years). For the characterization of the EG participants the Sitting-rising test and Berg Balance Scale will be used. Participants will be evaluated on an isokinetic dynamometer, in the execution modes of isometric and concentric/concentric at angular velocity of 90 and 120 °/s for flexion/extension of the knee and plantar flexion/dorsiflexion of the ankle, 30 and 120 °/s for flexion/extension of the hip and 30 and 180 °/s for adduction/abduction of the hip, synchronously with a signal acquisition system of surface electromyography (EMG) by telemetry. Will be collected the EMG of the gluteus maximus, multifidus, internal oblique, rectus femoris, vastus lateralis, tibialis anterior, biceps femoris and lateral gastrocnemius. After initial evaluation (1st evaluation) the participants of the EG remain with their daily activities and after eight weeks they will be revalued (equal the 1st evaluation). After a 1st revaluation will be initiated the training protocol with vibrating rod that will last for eight weeks, with two weekly sessions of 60 minutes each. Finally, after the training period will be performed the 2nd revaluation (equal the 1st evaluation). The YG participants will be evaluated only in a 1st evaluation. Biomechanical parameters of muscle strength and power, including peak torque, average torque, total work, average power, level of muscle activation and co-contraction, as well as temporal parameters of muscle contraction, such as the rate of torque development, rate of EMG rise, reaction time and acceleration time will be used for comparisons between younger and older; as well as for comparisons pre- and post- vibrating rod training in elderly women.