The impact of foot position on electromyographical activity of the superficial quadriceps muscles during leg extension

Mark Stoutenberg, Alessandra P. Pluchino, Fangchao Ma, Jennifer E. Hoctor, Joseph F. Signorile

Research output: Contribution to journalArticle

5 Scopus citations


This study investigated variations in electromyographic (EMG) responses of the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) due to foot position during leg extension. Twenty-four men and women (23.67 ± 4.02 years) performed 8 repetitions at 70% of 8 repetition maximum with their leg medially rotated, laterally rotated, and neutral. Repeated-measures analyses of variance indicated that the highest normalized root mean square (NrmsEMG) for the VM and VL occurred with medial rotation, and the highest NrmsEMG for the RF occurred with lateral rotation. Significant NrmsEMG increases and median power frequency decreases occurred across repetitions regardless of foot position. Therefore, medial rotation produced the greatest muscle activation for the VL and VM, whereas lateral rotation produced the greatest activation in the RF. These findings are applicable to athletes or bodybuilders who are seeking to selectively increase either the size or performance of a specific muscle of the quadriceps group.

Original languageEnglish (US)
Pages (from-to)931-938
Number of pages8
JournalJournal of strength and conditioning research
Issue number4
StatePublished - Nov 1 2005



  • Constant load resistance exercise
  • Fatigue
  • Muscle utilization pattern
  • Rectus femoris
  • Vastus lateralis
  • Vastus medialis

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Physical Therapy, Sports Therapy and Rehabilitation
  • Orthopedics and Sports Medicine

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