Déficit bilateral em exercício multiarticular para membros superiores

Abstract

Muscular strength is an important component for physical activity and performance of daily living activities. A phenomenon usually observed is that the capacity of generating maximum strength is compromised when the homologous extremities bilaterally contract. This phenomenon is called bilateral deficit. Thus, the aim of this work was to compare the electrical activity of the deltoid muscle, medial portion, during unilateral and bilateral contractions in a converging articulated military press machine, with 90% of maximum voluntary load (MVL), in nine men aged between 20 and 30 years, stature of 174 ± 5cm and body mass of 78 ± 15 kg. The myoelectrical signals were obtained through placement of differential active surface electrodes by EMG System of Brazil, a reference electrode (ground) and a signal conditioner module (electromyograph), which provided numerical data in RMS (root mean square) for results analysis. Each signal collected picked only the concentric phase of the movement and it had duration of three seconds. The results evidenced that during bilateral and unilateral exercise with 90% of MVL, the electric activity of the non-dominant extremity was significantly higher than in the dominant one (p = 0.018). When the values obtained in the work of dominant extremity are summed with the work of non-dominant extremity in the bilateral exercise (2.231 ± 504µv) and compared with the values obtained in the unilateral work (2.663 ± 701µv), bilateral deficit was found (p = 0.018). According to our study, it was verified that the bilateral deficit phenomenon is present in the medium deltoid muscle in the converging multiarticular military press exercise in individuals familiarized with resistance exercises.

Verbal instruction does not change myoelectric activity during seated row exercise in trained and untrained men

“…The untrained group showed higher EMG for the teres major (+22.53%) and triceps brachii long head (+17.73%) when compared to the trained group. Possibly this was due to the low level of intermuscular coordination between two or more muscles, which causes higher recruitment of motor units, raising the EMG levels to the same motor task with the same relative intensity 25 . Moreover, the untrained participants could be less used to this kind of effort and load intensity, resulting in a greater EMG 2 .…”

Déficit bilateral de las manifestaciones de la fuerza muscular de las extremidades inferiores en estudiantes universitarios

“…El entrenamiento de la fuerza ha cobrado gran importancia en los últimos años, no solo en deportes que dependen exclusivamente de ella sino en algunos que son eminentemente aeróbicos, en actividades de la vida diaria, en la estética y en la salud (Nazário-de-Rezende et al , 2012). Los ejercicios que se incluyen en el entrenamiento de la fuerza muscular pueden ser diversos y ejecutados ya sea de forma bilateral (con los dos miembros a la vez) o unilateral (con un solo miembro) (Ehlers Botton & Silveira Pinto, 2012).…”