Lateral Pelvis and Lumbar Motion in Seated and Standing Office Work and Their Association With Transient Low Back Pain.

OBJECTIVE

To assess frontal plane motion of the pelvis and lumbar spine during 2 h of seated and standing office work and evaluate associations with transient low back pain.

BACKGROUND

Although bending and twisting motions are cited as risk factors for low back injuries in occupational tasks, few studies have assessed frontal plane motion during sedentary exposures.

METHODS

Twenty-one participants completed 2 h of seated and standing office work while pelvic obliquity, lumbar lateral bending angles, and ratings of perceived low back pain were recorded. Mean absolute angles were compared across 15-min blocks, amplitude probability distribution functions were calculated, and associations between lateral postures and low back pain were evaluated.

RESULTS

Mean pelvic obliquity (sit = 4.0 ± 2.8°, stand = 3.5 ± 1.7°) and lumbar lateral bending (sit = 4.5 ± 2.5°, stand = 4.1 ± 1.6°) were consistently asymmetrical. Pelvic obliquity range of motion was 4.7° larger in standing (13.6 ± 7.5°) than sitting (8.9 ± 8.7°). In sitting, 52% (pelvis) and 71% (lumbar) of participants, and in standing, 71% (pelvis and lumbar) of participants, were considered asymmetric for >90% of the protocol. Lateral postures displayed weak to low correlations with peak low back pain ( ≤ 0.388).

CONCLUSION

The majority of participants displayed lateral asymmetries for the pelvis and lumbar spine within 5° of their upright standing posture.

APPLICATION

In short-term sedentary exposures, associations between lateral postures and pain indicated that as the range in lateral postures increases there may be an increased possibility of pain.