title: Gender variability in electromyographic activity, in vivo behaviour of the human gastrocnemius and mechanical capacity during the take-off phase of a countermovement jump.
abstract: OBJECTIVE
  The purpose of this study was to analyse gender differences in neuromuscular behaviour of the gastrocnemius and vastus lateralis during the take-off phase of a countermovement jump (CMJ), using direct measures (ground reaction forces, muscle activity and dynamic ultrasound).
  
  
  METHODS
  Sixty-four young adults (aged 18-25 years) participated voluntarily in this study, 35 men and 29 women. The firing of the trigger allowed obtainment of data collection vertical ground reaction forces (GRF), surface electromyography activity (sEMG) and dynamic ultrasound gastrocnemius of both legs.
  
  
  RESULTS
  Statistically significant gender differences were observed in the jump performance, which appear to be based on differences in muscle architecture and the electrical activation of the gastrocnemius muscles and vastus lateralis. So while men developed greater peak power, velocity take-offs and jump heights, jump kinetics compared to women, women also required a higher electrical activity to develop lower power values. Additionally, the men had higher values pennation angles and muscle thickness than women.
  
  
  CONCLUSIONS
  Men show higher performance of the jump test than women, due to significant statistical differences in the values of muscle architecture (pennation angle and thickness muscle), lower Neural Efficiency Index and a higher amount of sEMG activity per second during the take-off phase of a CMJ.
authors.affiliation: Department of Physical Activity and Sports Sciences, Faculty of Sports, UCAM, Catholic University San Antonio, Murcia, Spain.|UCAM Research Center for High Performance Sport, Catholic University San Antonio, Murcia, Spain.|Performance and Sport Rehabilitation Laboratory, Department of Sports Sciences and Physical Activity, Faculty of Physical Activity and Sports Sciences, University of Castilla-La Mancha, Toledo, Spain.
authors.forename: Jacobo Ángel
authors.initials: JÁ
authors.lastname: Rubio-Arias
authors.affiliation: Department of Physical Activity and Sports Sciences, Faculty of Sports, UCAM, Catholic University San Antonio, Murcia, Spain.|UCAM Research Center for High Performance Sport, Catholic University San Antonio, Murcia, Spain.|Performance and Sport Rehabilitation Laboratory, Department of Sports Sciences and Physical Activity, Faculty of Physical Activity and Sports Sciences, University of Castilla-La Mancha, Toledo, Spain.
authors.forename: Domingo Jesús
authors.initials: DJ
authors.lastname: Ramos-Campo
authors.affiliation: Department of Morphological Sciences, Histology Section, Faculty of Medicine, University of Córdoba, Maimónides Institute for Biomedical Research IMIBIC, Córdoba, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Peña Amaro
authors.affiliation: Performance and Sport Rehabilitation Laboratory, Department of Sports Sciences and Physical Activity, Faculty of Physical Activity and Sports Sciences, University of Castilla-La Mancha, Toledo, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Esteban
authors.affiliation: Performance and Sport Rehabilitation Laboratory, Department of Sports Sciences and Physical Activity, Faculty of Physical Activity and Sports Sciences, University of Castilla-La Mancha, Toledo, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Mendizábal
authors.affiliation: Performance and Sport Rehabilitation Laboratory, Department of Sports Sciences and Physical Activity, Faculty of Physical Activity and Sports Sciences, University of Castilla-La Mancha, Toledo, Spain.
authors.forename: José Fernando
authors.initials: JF
authors.lastname: Jiménez
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D001823:Body Composition; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength; D011237:Predictive Value of Tests; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging / Q000502:physiology*; D012737:Sex Factors; D014463:Ultrasonography; D055815:Young Adult
keywords: countermovement jump; ground reaction forces; muscle performance; muscular architecture; surface electromyography