Relative intensity of muscular effort during multi-joint movement

• Author / Creator

  Bryanton, Megan

• The purpose of this study was to evaluate muscular effort during the squat, a popular resistance training exercise for the triceps surae, quadriceps, hamstrings, and gluteus maximus. Ten females completed deep barbell squats, descending beyond a parallel thigh position, of increasing loads. Relative intensities were calculated for the hip and knee extensors and ankle plantar flexors. Significant depth effects were found for the hip and knee extensors, and load effects for all muscle groups (p< .001). Relative intensities increased with load, where lower squat depths elicited higher knee extensor effort levels. A limitation of inverse dynamics analyses to account for co-contraction was also evaluated. Higher quadriceps intensity levels were revealed at each load once hamstring co-contraction was added to the models. Findings suggest an important role of knee extensor strength in squatting performance and have applications in muscle performance testing in strength and conditioning, as well as rehabilitation settings.

• Subjects / Keywords

  • Multi-joint movement
  • Muscular effort
  • Relative intensity
  • Squat
  • Co-contraction

• Graduation date

  Fall 2011

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3Q65B

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.