[Purpose] The purposes of this study were: 1) describe a hierarchy of electromyographic
activity production, using percentage maximum voluntary contraction of lumbar iliocostalis
and lumbar multifidus muscles during prone, quadruped and sitting exercises; and 2)
identify optimal recruitment exercises for both lumbar iliocostalis as a global
multi-segmental stabilizer and lumbar multifidus as a segmental stabilizer. [Subjects]
Twelve healthy volunteers (six male and six female) aged 24 to 45 participated. [Methods]
Surface electromyographic activity data were collected bilaterally from lumbar
iliocostalis and lumbar multifidus muscles during exercises. [Results] Two-way ANOVA
showed that prone extension, and prone alternate arm and leg lifting exercises produce a
statistically significant difference in percent maximum voluntary contraction of lumbar
iliocostalis and lumbar multifidus bilaterally compared to other exercises. Quadruped
alternate arm and leg lifting exercises produce greater activity in lumbar multifidus
muscle than sitting exercises [Conclusion] Prone exercises generate the greatest
electromyographic activity and may be the most effective exercises for strengthening both
lumbar iliocostalis and lumbar multifidus muscles. Quadruped alternate arm and leg lifting
produces electromyographic activity at the recommended percent maximum voluntary
contraction for training the lumbar multifidus in its role as a segmental stabilizer and
is an effective training exercise for this goal.