Postural control in patients with lumbar disc herniation in the early postoperative period

Abstract

Chronic spinal disc disease leads to disorders in postural movement coordination. An incorrect asymmetrical movement pattern for the lower limbs loading impairs proprioception and deteriorates postural stability, particularly when the vision is occluded. The standard surgical treatment improves biomechanical conditions in the lumbar spine, reduces pain, yet does it reduce the stability deficit in the upright position? An answer to the latter question would help work out targeted therapy to improve postural stability. We hypothesized that the standard surgical treatment would improve postural stability reflected by decreased sway variability accounting for better use of proprioceptive inputs postoperatively. Thirty-nine patients with lumbar disc herniation participated in the study. Their postural sway was recorded in anterior/posterior and medial/lateral planes with their eyes open or closed (EC) before and after surgery. The variability, range, mean velocity of the recorded time series and the area of the ellipse enclosed by the statokinesiogram were used as measures of postural stability. Preoperatively, EC condition resulted in an increased variability and mean velocity of postural sway, while postoperatively it caused an increase in sway mean velocity and sway area only with no effect on sway variability and range. The comparison of the balance before and after the surgery in the EC condition showed significant decrease in all parameters. In the early postoperative period, the patients recover the ability to control their postural sway in EC within normal limits, however, at the expense of significantly increased frequency of corrective torques. It is probably a transient short-term strategy needed to compensate for the recovery phase when the normal weighting factors for all afferents are being reestablished. We propose that this transient postoperative period may be the best timing of therapeutic intervention targeted at facilitating and reinforcing the acquisition of correct motor patterns.

Altered postural control in persons with cognitive impairment during visual feedback tasks

“…This result agreed with the corresponding changes in COP mean velocity and indicated increased activity of postural control system in the control group during the VFB task [16,25]. However, the frequency data provided more precise information regarding the postural mechanisms involved than velocity because in contrast to velocity, which depends on both: the COP amplitude and frequency, there is only one way to increase frequency of oscillations in a mechanical system when its configuration remains constant -to increase its stiffness [26]. Specifically, according to the demands of the VFB task, the subjects in the control group used postural strategy with tighter control (increased stiffness) of body sway [14,27] to produce higher frequency of corrective adjustments.…”

Manipulation under anesthesia for patients with failed back surgery: retrospective report of 3 cases with 1-year follow-up

“…[14][15][16][17] When patients have spinal fusion surgery to correct the initial origin of the chronic pain (ie, nerve root compression, spinal cord effacement), they still maintain these abnormal gait and postural adaptations. 18 These adaptations may then themselves promote chronic pain patterns and also promote accelerated degeneration of spinal motion segments adjacent to the surgery sites by increasing the gravitational stress upon them. 19 The MUA procedure may then be appropriate to address these postural adaptations by improving joint mobility in those joints taking part in the postural adaptive response.…”

Assessment of static posturography and pedobarography for the detection of unilateral forelimb lameness in ponies

“…Based on widespread application in humans, the most frequently used PT parameters for the diagnosis of postural alterations are as follows: (1) statokinesiograms, defined as the area determined by an ellipse that contains 90% of the recorded points of the COP trajectory [ 24 ], measured in mm 2 , and a smaller area is associated with superior stability [ 22 , 25 ]; (2) mean COP X and Y (mm), which quantifies the mediolateral and craniocaudal COP displacements independently, and, similar to statokinesiograms, smaller displacement is associated with better stability [ 25 , 26 ]; (3) COP length (m), which is also called total path length [ 24 ], is the length of the line that joins the recorded points of the COP trajectory, where a higher value means more instability [ 27 ]; (4) LFS (length in function of surface), which is defined as the correlation coefficient between the COP length and its surface. This parameter provides information about the accuracy of postural control and the effort made by the subject [ 28 ], which increases its value [ 29 ]; (5) mean velocity (mm/s) of COP sway increases with instability, and this parameter may be one of the most accurate variables for the assessment of postural stability [ 30 , 31 ].…”