Effect of foot orthotics
on quadriceps and gluteus medius electromyographic activity during
selected exercises
Jay Hertel, PhD, ATC. Brent R. Sloss, ATC. Jennifer
E. Earl, PhD, ATC. Effect of foot orthotics on quadriceps and
gluteus medius electromyographic activity during selected exercises.
Archives of Physical Medicine and Rehabilitation. January 2005
• Volume 86 • Number 1
Hertel J, Sloss BR, Earl JE. Effect of foot orthotics on quadriceps
and gluteus medius electromyographic activity during selected
exercises.
Objective To compare electromyographic activity of the vastus
medialis, vastus lateralis, and gluteus medius during functional
activities in subjects with different foot types while wearing
various off-the-shelf foot orthotics.
Design Experimental, controlled; 3 foot-type groups (pes planus,
pes cavus, pes rectus) each tested in 4 orthotic conditions while
performing 3 different exercises.
Setting Laboratory.
Participants Thirty healthy young adults, 10 with each foot type.
Interventions Four conditions: no orthotic, 7° medial rearfoot
post, 4° lateral rearfoot post, and neutral rearfoot post.
Main outcome measure Surface electromyographic activity for the
vastus medialis, vastus lateralis, and gluteus medius during single-leg
squatting, lateral stepdown, and maximum vertical jump exercises.
Results Greater vastus medialis and gluteus medius activity was
found with all 3 orthotic conditions, regardless of subject foot
type, during the single-leg squat and lateral stepdown. Less vastus
lateralis activity was found with the vertical jump with all orthotic
conditions, again regardless of foot type.
Conclusions During slow controlled exercises such as the single-leg
squat and lateral stepdown, vastus medialis and gluteus medius
activity may be enhanced with an off-the-shelf orthotic, regardless
of posting or foot type. These same findings do not appear to
carry over to a more explosive task such as the maximal vertical
jump.
