Influence of a dynamic seating habit on lumbar motor control in schoolchildren.

BACKGROUND: Adequate motor control is considered important for spinal stability and the prevention of low back pain in adulthood and in childhood. OBJECTIVE: Given that the sitting position can affect proprioception, this study aimed to evaluate the influence of using at school a triangular and dynamic cushion on schoolchildren's trunk motor control. METHODS: Thirty 8-year-old schoolchildren were randomized into a control group (n= 15) and a "cushion group" (n= 15), in which the children used the cushion for one year and a half. At the end of this period, a 3D-analysis was used to assess lumbar spine proprioception by means of a trunk repositioning task performed blindfolded in a seated position in two conditions (on a stable and on an unstable surface). RESULTS: The schoolchildren in the cushion group performed better at the trunk repositioning task (p= 0.02) and hold their lumbar lordosis (p= 0.03) better than the control children, in both conditions (stable and unstable). CONCLUSIONS: This preliminary study suggests that daily use of a triangular dynamic cushion has a beneficial impact on children's lumbar proprioception. Further studies are needed to confirm these results and investigate the effectiveness of its use to prevent low back pain in adulthood.

Relevance of adding a triangular dynamic cushion on a traditional chair: A 3D-analysis of seated schoolchildren.

BACKGROUND: Low back pain is highly prevalent in the general population and is even reported as early as at primary school. A poor sitting position has been suggested as an etiologic factor. This study analysed, in primary schoolchildren, the influence of a triangular dynamic cushion that aims to help children maintain their physiological lumbar lordosis and to induce movement to reduce the static effect of the sitting position. METHODS: Thirty 8-year-old children took part in this study. A 3D analysis combined with electromyography was used to evaluate the biomechanics and the related muscle activation in two sitting positions (with and without a triangular cushion on a horizontal stool) during a 15-minute working task. In addition, the force of the feet on the ground was assessed with a force plate. FINDINGS: The cushion improved the trunk-thighs angle, lumbar lordosis, anterior pelvis tilt, and feet support on the ground (p<0.0001). In addition, sitting on the cushion appeared to be more dynamic (p<0.05) and induced a decrease of the lumbar paravertebral muscle activity (p<0.01). INTERPRETATION: Sitting on a dynamic triangular cushion tends to favour the "ideal" siting position usually described in the literature and to decrease the level of paravertebral muscle recruitment. Seeing that sitting position is a risk factor to develop low back pain, the cushion could be a solution to prevent it.