Postural Sway
The capability of a person to maintain balance in an
upright posture requires a complex integration of accurate
sensory input and precisely coordinated motor output
[39]. Sensory inputs include the vestibular system,
the visual system and the proprioceptors in muscles and
joints. Muscle activity must be simultaneously controlled
at three levels to achieve stability: spinal reflex, brain
stem balance and cognitive programming [40]. Disturbances
to the neuromuscular system can affect the
degree of efficiency and accuracy with which posture is
maintained [41].
LBP patients have impaired postural stability compared
to healthy individuals [42-46]. It is hypothesized
that the reduced proprioceptive acuity derived from
muscle or joint mechanoreceptors can be a cause of
altered postural sway [47]. Another theory is that LBP
patients have impaired short-term memory that leads to
delays in processing postural control information and
increased sway [48].