Research-Supported Advice on Bending and Lifting.
Conventional wisdom advises no bending and lifting only in a straight back or arched position.
As to the first, it is now accepted by researchers that bending the back is essential for the health of the discs as it continually moves all the joints of the spine, so aiding in drawing in nutritional fluids. It also keeps the facet joints mobile so preventing congestion.
Research now contends, that volitional control in a slightly rounded lumbar region, using abdominals and mulifidus, is a safer option as it brings in the biomechanical restraints of the facet joints, discs and ligaments. With a back already damaged this is even more essential, to prevent further damage. A rounded back is more stable and safe.
Eight reasons not to arch the back in lifting:
- Unnatural, awkward and unstable
- Discs are unloaded reducing stability
- Facet joints loaded
- Disables posterior ligamentus lock and lumbar-dorsal fascia
- Hard to pull in tummy
- Reinforces emergency function of erector spinae
- Causes reflex under-activity of multifidus
- Makes it hard to prime discs to make segments more stable
- Farfan and Gracovetsky 1985: Lumbar spine should remain fully flexed to engage the posterior ligamentus lock.
- Purlsow 1989: Back muscle strength substantially higher in flexed postures.
- Adams, McNally, Chinn, Dolan. 1994: Not necessary to preserve the lordosis when lifting.
- Bogduk 1997: Contraction of back muscles is distinctly undesirable as it disengages posterior ligaments.
- Daggfeldt and Thorstensson 1997 Spinal unloading effect is greatest with the spine in a flexed position.
- Dolan and Adams 2001: Moderate lumbar flexion equalises compressive stress across the entire disc.
- Arjmand, Shirazi-Adl 2005:freestyle moderate flexion is the position of choice in flexion.
- Arjmand, Shirazi-Adl 2006: Small flattening of lumbar curvature yields smaller compression and shear forces.
- Dolan, Mannion, Adams 1994: ‘Widely held belief that weightlifters should, or even can, maintain a normal lumbar lordosis is evidently mistaken,