A non-randomized clinical trial to assess the impact of nonrigid, inelastic corsets on spine function in low back pain participants and asymptomatic controls.

BACKGROUND CONTEXT: Although previous studies suggest braces/corsets can reduce acute pain, no prior study has assessed back function after bracing with both self-reported and objective measures. Use of both self-reported and objective measures of spine function together may be important given evidence they assess unique aspects of function. PURPOSE: The aim was to assess both self-reported and objective measures of spinal function before, and after, use of a nonrigid, inelastic lumbar brace. STUDY DESIGN/SETTING: This was a non-randomized clinical trial. PATIENT SAMPLE: The sample included acute low back pain (LBP) participants and asymptomatic controls. OUTCOME MEASURES: Oswestry Disability Index (ODI), spinal stiffness, and muscle endurance were the outcome measures. METHODS: Three groups were studied: -LBP/-Brace (n=19), -LBP/+Brace (n=18), and +LBP/+Brace (n=17). Both groups of braced participants were instructed to wear the brace continually for 2 weeks with the exception of bedroom and bathroom activities. Before and after the 2-week period, three measures of spinal function were performed: spinal stiffness via motorized indentation of the L3 spinous process, a modified Sorensen test (timed lumbar extension against gravity), and the ODI. Repeated measures analyses of variance were conducted for all three outcomes. RESULTS: Among the groups, ODI scores decreased significantly for the +LBP/+Brace group (p<.001) compared with the other two groups. The +LBP/+Brace mean ODI score decreased 3.71 points (95% confidence interval [CI] 2.01-5.40) compared with the -LBP/-Brace group and decreased 3.48 points (95% CI 1.77-5.20) compared with the -LBP/+Brace group. Change scores for the Sorensen test were significantly increased in the +LBP/+Brace group (p=.037) compared with the -LBP/-Brace group (22.47s 95% CI 8.14-36.80). Spinal stiffness did not change significantly between groups. CONCLUSIONS: This study demonstrates that lumbar function assessed by self-reported and objective measures does not worsen when nonrigid, inelastic bracing is used for short periods of time for those with, or without, back pain. These data add to the existing literature that suggests short-term use of nonrigid, inelastic bracing for acute LBP does not decrease spinal function when measured separately with subjective or objective tools.

The effect of application site of spinal manipulative therapy (SMT) on spinal stiffness.

BACKGROUND CONTEXT: Like other factors that can influence treatment efficacy (eg, dosage, frequency, time of day), the site of treatment application is known to affect various physical interventions such as topical anesthetics and cardiopulmonary resuscitation. Like these examples, spinal manipulative therapy (SMT) is a physical intervention that may exhibit maximal benefit when directed to a specific site. Whereas numerous studies of SMT efficacy have produced mixed results, few studies have taken into account the site of SMT application. PURPOSE: To determine if the site of SMT application modulates the effect of SMT in an anesthetized feline model. STUDY DESIGN: Spinal manipulative therapy applied to specific anatomic locations randomized in a Latin square design with a no-SMT control. OUTCOME MEASURES: Physiologic measures (spinal stiffness). METHODS: Simulated SMT was delivered by a validated mechanical apparatus to the intact lumbar spine of eight anesthetized felines at four unique sites: L6 spinous process, left L6 lamina, left L6 mammillary process, and L7 spinous process. To measure spinal stiffness, a separate indentation load was applied mechanically to the L6 spinous process before and after each SMT application. Spinal stiffness was calculated from the resulting force-displacement curve as the average stiffness (k) and terminal instantaneous stiffness (TIS). RESULTS: Relative to the no-SMT control, significant decreases in spinal stiffness followed the SMT when L6 spinous and L6 lamina were used as the contact site. Terminal instantaneous stiffness significantly decreased -0.48 N/mm (upper, lower 95% confidence interval [-0.86, -0.09]) with L6 spinous as the contact site and decreased -0.44 N/mm (-0.82, -0.05), with the L6 lamina as the contact site. k increased 0.44 N/mm (-0.01, 088), using L6 spinous as the contact site. CONCLUSIONS: Decreases in terminal spinal stiffness were observed after SMT delivered at some application sites but not the others. The results suggest that SMT contact site modulates SMT's effect on spinal stiffness in a feline model. Changes in spinal terminal instantaneous spinal stiffness were similar in magnitude and direction to those observed in symptomatic human subjects who report benefits after SMT.