EMG profile in two different angles during maximum voluntary isometric contraction in squat exercise

  • Alex Souto Maior
  • Leonardo Marmelo
  • Silvio Marques-Neto

Abstract

The aim of the present study was to analyze the electric activity of the vastus medialis (VM) and vastus lateralis (VL) in two differing angles (70° and 90° of knee flexion) during maximum voluntary contraction in squat exercise. Fifteen male subjects composed the sample of the study. As criteria they were untrained for more than 12 months (age of 28.0 ± 4.6 years, height of 180.0 ± 5.2 cm, weight of 80.0 ± 3.2 kg and body index mass of 24.2 ± 1.6 kg/m²). Subjects accomplished three maximum voluntary isometric contractions (MVIC) in squat exercise with 70° and 90° of knee flexion and separate at least in 72 h each. Data normalization occurred by average of values in RMS. Procedure adopted followed ISEK's recommendations. No significant differences (p > .05) were found between the angles VL 70° vs VM 70°, VL 90° vs VM 90°, VL 70° vs VL 90°, and VM 70° vs VM 90°. Results allowed for the conclusion that there seems to exist a balance in electric activity between VL and VM during MVIC with 70° and 90° of knee flexion in untrained subjects.
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Original Article