title: Reliability of a combined biomechanical and surface electromyographical analysis system during dynamic barbell squat exercise.
abstract: An analysis system for barbell weightlifting exercises is proposed to record reliable performance and neuromuscular responses. The system consists of surface electromyography (sEMG) synchronized with electrogoniometry and a barbell position transducer. The purpose of this study was to establish the reliability of the three components of the system. Nine males (age 28.9 ± 4.8 years, mass 85.7 ± 15.1 kg) performed squat exercise at three loads on three separate trial days. A data acquisition and software system processed maximal knee angle (flexion), mean power for the concentric phase of squat exercise, and normalized root mean square of the vastus lateralis. Inter-trial coefficients of variation for each variable were calculated as 5.3%, 7.8%, and 7.5% respectively. In addition, knee joint motion and barbell displacement were significantly related to each other (bar displacement (m) = 1.39-0.0057 × knee angle (degress), with goodness-of-fit value, r² = 0.817), suggesting knee goniometry alone can represent the kinematics of a multi-joint squat exercise. The proven reliability of the three components of this system allows for real-time monitoring of resistance exercise using the preferred training methods of athletes, which could be valuable in the understanding of the neuromuscular response of elite strength training methods.
authors.affiliation: Strength and Conditioning, English Institute of Sport, Manchester, UK. raphaelbrandon@mac.com
authors.forename: Raphael
authors.initials: R
authors.lastname: Brandon
authors.forename: Glyn
authors.initials: G
authors.lastname: Howatson
authors.forename: Angus
authors.initials: A
authors.lastname: Hunter
mesh_terms: D000328:Adult; D004576:Electromyography / Q000379:methods*; D006801:Humans; D007717:Knee / Q000502:physiology; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D015203:Reproducibility of Results; D055070:Resistance Training; D012984:Software; D014891:Weight Lifting / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult