title: Muscular activation patterns during active prone hip extension exercises.
abstract: BACKGROUND
  Changes in activation patterns of hip extensors and pelvic stabilizing muscles are recognized as factors that cause low back disorders and these disturbances could have an impact on the physiological loading and alter the direction and magnitude of joint reaction forces.
  
  
  OBJECTIVE
  To investigate activation patterns of the gluteus maximus, semitendinosus and erector spinae muscles with healthy young individuals during four different modalities of therapeutic exercise.
  
  
  METHODS
  Thirty-one volunteers were selected: (16 men and 15 women), age (24.5+/-3.47years), body mass of 66.89+/-11.89kg and a height of 1.70+/-0.09m). They performed four modalities of therapeutic exercise while the electromyographic activity of the investigated muscles was recorded to determine muscle pattern activation for each exercise.
  
  
  RESULTS
  Repeated measure ANOVA revealed that muscle activation patterns were similar for the four analyzed exercises, starting with the semitendinosus, followed by the erector spinae, and then, the gluteus maximus. The gluteus maximus was the last activated muscle during hip extension associated with knee flexion (p<0.0001), knee extension (p<0.0001), and with lateral rotation and knee flexion (p<0.05).
  
  
  CONCLUSIONS
  Findings of the present study suggested that despite individual variability, the muscle firing order was similar for the four therapeutic exercises.
authors.affiliation: Department of Physical Therapy, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, 6627, Campus Pampulha, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Ana Cristina Lamounier
authors.initials: AC
authors.lastname: Sakamoto
authors.forename: Luci Fuscaldi
authors.initials: LF
authors.lastname: Teixeira-Salmela
authors.forename: Fátima Rodrigues
authors.initials: FR
authors.lastname: de Paula-Goulart
authors.forename: Christina Danielli Coelho
authors.initials: CD
authors.lastname: de Morais Faria
authors.forename: Cristiano Queiroz
authors.initials: CQ
authors.lastname: Guimarães
mesh_terms: D000328:Adult; D001415:Back; D002081:Buttocks; D004576:Electromyography; D005081:Exercise Therapy; D005260:Female; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult