A Novel Distractive and Mobility-Enabling Lumbar Spinal Orthosis

摘要

Lumbar spinal orthoses are often used as non-surgical treatment and serve to support the spine and alleviate low back pain. More recently, dynamic orthoses claiming to decompress the spine have been introduced. A previously-developed dynamic mobility orthosis (DMO1) prototype provided mobility and spinal off-loading, but had high bending moments and did not maintain spinal off-loading throughout extended ranges of movement. The objective was to design a new orthosis prototype (DMO2) that reduced bending moment build up and sustained spinal off-loading during flexion and extension movement. A mechanical analogue upper torso model and a programmable robotic testing platform were used to design features of DMO2: a mobility-enabling component and a distractive force component. Test conditions for DMO2 were 300N of applied vertical torso load over a range of 25deg flexion to 10deg extension. Loads carried by the brace were determined throughout flexion and extension ranges. Applied moments to upper torso model and transferred moments to spine were measured. The difference in applied and transferred moments represented brace moments. DMO2 improved loadsharing capacity from 172N to 290N at end range flexion and from 247N to 293N at end range extension. End range applied moments (flexion-DMO1: 32.4Nm / DMO2: 21.7Nm, extension-DMO1: 15.0Nm / DMO2: 10.9Nm) and brace moments (flexion-DMO1: 18.6Nm / DMO2: 6.6Nm, extension-DMO1: 15.0Nm / DMO2: 4.4Nm) were reduced. A novel dynamic spinal orthosis was designed that maintained spinal off-loading and required minimal effort for movement.