BME Seminars
BME 881 Seminar: Wednesday, November 25, 2009 at 4:00 pm
in 145 Mount Hall, 1050 Carmack Rd
Evaluating The Effect Of A 10-Week Stabilization Exercise Program On The Postural Stability And The Neuromuscular Control Of The Spine In Subjects With Subacute Recurrent Low Back Pain
Anand Navalgund, Ph.D. Candidate
Department of Biomedical Engineering,
The Ohio State University
Abstract
Low back pain (LBP) is one of the most common medical problems afflicting around 80% of the world's population at one time or other in their lifetime. The LBP episodes usually resolve quickly but a high number of individuals often relapse and suffer repeated episodes of LBP. This leads to a loss in work productivity and a decrease in their quality of life. Hence, it becomes imperative to understand and possibly correct the underlying factors responsible for LBP. Alterations in trunk muscle response patterns such as delays in muscle onset times, increased agonist/antagonist co activation levels, and loss of anticipatory control have been observed in subjects with LBP. Altered muscle responses contribute to impaired postural control and instability which may be a contributing factor to the recurrence of LBP. Stabilization exercise programs have been shown to decrease the risk of LBP recurrence in a select group of patients with acute, first episode LBP. However, it is not known if the stabilization exercise programs influences to improve the underlying neuromuscular response patterns and postural stability. Hence, the purpose of this study was to assess if a 10-week stabilization exercise program influenced to improve postural stability and alter the neuromuscular control in subjects with LBP. Two experiments were designed for that purpose: 1) A sudden perturbation test to assess the trunk muscle reflex responses, and 2) A seated postural control task to assess postural stability and trunk equilibrium control. 30 subjects (15 subjects with sub acute recurrent LBP, 15 healthy) aged between 18-55 years participated in the study. The LBP group was tested before (PRE) and after (POST) following the 10-week physical therapy intervention program. The healthy control (CNTL) group was tested on one occasion. In the sudden perturbation test it was observed that the subjects with LBP at PRE therapy had delayed and dampened trunk muscle reflexes compared to the CNTL group subjects. Postural stability assessed using a fractional Brownian motion analysis of the force plate data revealed that the subjects with LBP at PRE therapy had increased postural sway and large trunk displacements. In addition, the subjects with LBP also displayed increased amounts of agonist/antagonist co activation during the unstable periods of the seated postural task compared to the CNTL group subjects. At POST therapy in the subjects with LBP, the reflex responses remained delayed but there was a significant increase in the reflex amplitudes. In the seated postural task, there was a decrease in the postural sway and a reduction in their trunk displacements. However there was no change in the agonist/antagonist co activation levels during the unstable periods of the seated postural task. In conclusion, a 10-week stabilization program influenced to improve the neuromuscular control of the spine and postural stability in subjects with LBP.
