The purpose of this systematic review was to investigate the effect of dynamic sitting on trunk muscle
activation in sitting. Electronic databases were searched by two independent reviewers. Studies were
included if they compared the effect of dynamic sitting on trunk muscle activation to a more static sitting
condition. Seven studies were eligible for inclusion, six of which were rated as“high-quality”using the
PEDro scale. Five studies reported no difference in trunk muscle activation. Two studies reported a dif-ference in trunk muscle activation, yet this was associated with increased discomfort, increased fatigue
and greater spinal shrinkage. Furthermore, the changes reported in these two studies may be more
related to the absence of a backrest rather than dynamic sitting. Therefore, thefindings of this review
suggest dynamic sitting does not significantly change trunk muscle activation. No randomised clinical
trials or longitudinal design studies were found which evaluated the effect of dynamic sitting on trunk
muscle activation, limiting the ability to make definitive conclusions about causality. The implications of
the results, and recommendations for future research, are discussed