Co-contractive activation of the superficial multifidus during volitional preemptive abdominal contraction.

Objective: To investigate whether the superficial multifidus (MF) muscle at the lower lumbar spine displayed co-contraction during volitional preemptive abdominal contraction (VPAC) through the abdominal drawing-in maneuver (ADIM) or the abdominal bracing maneuver (ABM) in 3 different postural positions.

Design: A within-subject cohort design.

Setting: A clinical laboratory.