Objective: To evaluate the efficacy of a nine-day accommodation protocol on reducing perceived discomfort while sitting on a stability ball (SB); trunk muscle activity levels and lumbar spinal postures were also considered.

Background: Previous studies have compared SB sitting to office chair sitting with few observed differences in muscle activity or posture; however, greater discomfort during SB sitting has been reported.  These findings may indicate an accommodation period is necessary to acclimate to SB sitting.

Methods: Six males and six females completed two separate, two-hour sitting sessions on an SB.  Half the participants completed a nine-day accommodation period between the visits while the other half did not use an SB during the time. On both occasions, self-reported perceived discomfort ratings were collected along with erector spinae and abdominal muscle activity and lumbar spinal postures.

Results: Discomfort ratings were reduced in female participants following the accommodation; no effects on muscle activation or lumbar spine postures were observed.

Conclusion: Accommodation training may reduce perceived low back discomfort in females. Trunk muscle activity and lumbar spine postures during seated office work on an SB did not differ between groups; however, greater sample power was required to conclusively address these variables.

Application: When deciding whether to use an SB in place of a standard office chair, this study indicates females electing to use an SB can decrease discomfort by following an accommodation protocol; no evidence was found to indicate SB chair use will improve trunk strength or posture, even following an accommodation period.