The effects on postural control and low back pain according to the types of orthoses in chronic low back pain patients (2025)

Abstract

[Purpose] This study investigated how types of lumbosacral orthoses applied to patientswith chronic lumbar pain affect postural control and low back pain. [Subjects and Methods]Ten subjects were randomly selected and allocated to each a group wearing soft lumbosacralorthoses and a group wearing rigid lumbosacral orthoses. They wore the lumbosacralorthoses for 4 weeks. Pain index and postural control were measured on the first day ofwearing lumbosacral orthoses and 4 weeks later. Pain index was evaluated using a visualanalogue scale, and postural control was measured using a Balance measurement system. Themeasurements examined included the overall balance index, anteroposterior balance index,and mediolateral balance index. [Results] There were statistically meaningful within-groupdifferences in all variables, the visual analogue scale, overall balance index,anteroposterior balance index, and mediolateral balance index, in the group wearing softlumbosacral orthoses. There were meaningful differences in visual analogue scale, overallbalance index, and mediolateral balance index in the group wearing rigid lumbosacralorthoses. Furthermore, there was a meaningful difference in anteroposterior balance indexbetween the group wearing soft lumbosacral orthoses and the group wearing rigidlumbosacral orthoses. [Conclusion] The results of the present study showed that wearingsoft lumbosacral orthoses was more effective than wearing rigid lumbosacral orthoses.

INTRODUCTION

Low back pain is a pain appearing between 12th rib and hip with or without leg pain1⁾. It is one of the most common diseases, andthe prevalence rate of this disease is 60 to 85% over the course of an entire lifetime and15 percent among adults2^, 3⁾. About 10% of patients with low back pain have low back painfor more than 6 weeks, and 5% of these patients have pain for more than 3 months. So lowback pain brings about a decline in physical activity due to difficulties faced in dailyliving and emotional stress. It has negative effects such as muscle atrophy, decrease ofmuscle strength and bone density, and deformation of the musculoskeletal system through lossof the balance of the normal spine4⁾.Patients with low back pain are given improper sensory information on the location of thebody in relation to gravity and supporting surfaces due to changes in the character andquantity of proprioceptive inputs from muscle spindles, Golgi tendon organs, joints, andskin receptors5⁾. Various problems occur inthe somatosensory system of patients with chronic low back pain. Decrease of the mobilityand stability of the waist occurs in these patients, and these bring about a decline ofmuscle strength and coordination capability and a change in proprioception6^, 7⁾.These disabilities of the musculoskeletal system affect balance performing ability and limituse of a proper exercise strategy in perturbation3⁾. In particular, patients with low back pain have a decreased balanceability compared with normal individuals5⁾.When the human body is exposed to an unexpected load, muscles have to respond quickly tomaintain the body’s balance and posture against the load. It is said that patients with lowback pain will have problems with balance and maintaining posture caused by a delayedresponse time8^, 9⁾. In patients with low back pain, wearing an orthosis is considered amethod of solving these problems, as it provides mechanical support and psychologicalstability. As a result, it decreases low back pain by decentering the weight of the upperbody concentrated on the waist10⁾. Inparticular, it is said that it can stabilize the lumbosacral area by decreasing lordosis andsegmental movement of the lumbar body11⁾.Orthoses can be divided into soft and rigid orthoses according to the material comprisingthem. Soft orthoses are called corsets or belts and are made from a neoprene material. Theycan increase the intra-abdominal pressure and improve low back pain by altering the musclesaround the trunk and abdomen. Rigid orthoses are made from polyethylene and are prescribedto limit movement of the spine locally or segmentally12^, 13⁾. There is lack ofresearch on comparing these two types of orthoses. Therefore, the aim of this study was toinvestigate how application of these two types of lumbosacral orthoses to patients withchronic low back pain affects postural control and low back pain.

SUBJECTS AND METHODS

The institutional review board of Sehan University approved the research ethics of thisresearch as a clinical trial (document number 2016-2), and all subjects understood thepurpose of the study very well and provided written informed consent prior to participationin the study, in accordance with the ethical standards of the Declaration of Helsinki.Twenty patients with chronic low back pain were registered as subjects for this prospectiveexperimental research. The experiment was conducted during the 4 weeks starting on March 14,2016, and ending on April 8, 2016. This research selected subjects who had low back pain formore than 3 months and no vestibular disease or disease in the ear, nose, and throat.Furthermore, it selected patients who had no neuropsychiatric impairments, visual handicaps,or episodes of dizziness or mild headache. Ten subjects were randomly assigned to each of agroup wearing soft orthoses and a group wearing rigid orthoses (Table 1). They wore the orthoses for 4 weeks, and the pain index and postural controlwere measured on the first day they wore the orthoses and 4 weeks later. Pain index wasevaluated using a visual analogue scale (VAS). Postural control was measured using a BiodexSystem 3 isokinetic dynamometer (Biodex Medical System, Shirley, New York, USA). Subjectsstood on a fixed foot plate for measurement of postural control. The foot plate was set suchthat it could move within a range of 5 degrees so that the central point of the subjectscould be adjusted before testing. It has the following limits with respect to movement: 8degrees anterior, 4 degrees posterior, and 16 degrees lateral. The mean angle out of centerbased on biomechanics was measured and converted into a stability index. A low stabilityindex indicates a stable state, and a high stability index indicates an unstable state. Themeasurements examined included the overall balance index (OBI), anteroposterior balanceindex (API), and mediolateral balance index (MBI). The change in overall movement wasmeasured with the OBI, the change in the sagittal plane was measured with the API, and thechange in the coronal plane was measured with the MBI. Data analysis was performed usingPASW Statistics for Windows, Version 18.0 (SPSS Inc., Chicago, IL, USA), and the generalcharacteristics of the subjects were tested for normality using the Shapiro-wilk test. Thepaired t-test was used to compare changes within groups, i.e., the rigid orthoses group andsoft orthoses group. ANCOVA was used to compare changes between groups. The significancelevel was set to α=0.05.

RESULTS

The results of comparison by paired t-test between before and after application of theorthoses revealed statistically meaningful within-group differences in all variables, i.e.,VAS (p<0.01), OPI (p<0.05), API (p<0.001), and MBI (p<0.05), in the groupwearing soft orthoses (Table 2). There were meaningful differences in VAS, OBI, and MBI in the group wearingrigid orthoses (p<0.05) (Table 3). Furthermore, the results of comparison between the groups by ANCOVA revealedthat there was a meaningful difference in API in the group wearing soft orthoses(p<0.01). The results showed that wearing soft orthoses was more effective than wearingrigid orthoses (Table 4).

DISCUSSION

This study compared pain index and postural control measurements between before and afterwearing soft lumbosacral orthoses and rigid lumbosacral orthoses for 4 weeks in 20 subjectswith chronic low back pain (10 in each group) to investigate the effects on postural controland pain. It has been reported that patients with low back pain exhibit a decrease inendurance, decrease in flexibility, and limited range of motion and also that these symptomsaffect balance ability compared with normal individuals5^, 14⁾. Lumbosacral orthoses forpatients with low back pain can decrease low back pain and help to improve balance abilityby stabilizing the lumbosacral area10^, 11⁾. Redford et al.15⁾ reported that lumbosacral orthoses used a lot by patientswith low back pain can mitigate pain by limiting movement of the trunk and decreasing theload on the waist by transmitting forces applied to intervertebral discs to soft tissuesurrounding the abdomen. Million et al.16⁾divided their subjects into a group wearing a lumbosacral corset and a group not wearing thecorset. They showed that pain decreased in the group wearing the lumbosacral corset. Sinakiet al.17⁾ reported that wearing a spinalweighted kypho-orthosis can increase location awareness of the vertebral joint orproprioception, in improve balance and walking quality, and decrease low back pain byincreasing the strength of the back extensor muscle patients with osteoporosis-kyphosis over60 years old and at risk of falls. The present study supported advanced research through theresult that pain decreased in both groups, i.e., the soft lumbosacral orthoses and rigidlumbosacral orthoses groups. It is considered that the mechanical characteristics oflumbosacral orthoses decrease pain by increasing the stability of the spine and pelvis. Vogtet al.18⁾ showed that lumbosacral orthosescan increase joint position sense by increasing afferent proprioceptive inputs throughmechanoreceptors of the skin and facilitate voluntary extension of the spine, improveposture, and decrease lordosis of the spine effectively by providing presentment aboutproper skill of movement and that it can help to maintain proper posture in the lumbarvertebrae via the three-point pressure principle. Kawaguchi et al.19⁾ reported that a lumbar orthosis increased the musclestrength of the back and abdomen and decreased muscle activity in their study of 31 men. Itis said that a lumbar orthosis can enable muscles to work effectively to perform a task.Ivanic et al.20⁾ reported that the softspine orthosis, as a corset type, is designed to increase passive stability and uprightnessof the waist compared with those resulting from use of a rigid spine orthosis. They alsosaid that soft lumbosacral orthoses are more effective than rigid lumbosacral orthoses. Thepresent study showed that OBI, API and MBI decreased meaningfully between before and afterthe experiment in the soft orthoses group but that there were meaningful differences in onlyOBI and MBI in the rigid orthoses group. These result showed that the soft orthoses weremore effective than the rigid orthoses in the present study. This supports the findings ofprevious studies indicating that orthoses do not affect the activity of the abdominalmuscles or the ability of the lumbar vertebrae joints in spite of the fact that they becamethe cause of a decrease in muscle activities or the cause of stiffness in the waste20^, 21⁾. The API represents the change in postural control in the sagittalplane. Rigid orthoses are mainly prescribed to protect the spine or facilitate healing andto limit movement of the spine locally or segmentally13⁾. It has also been reported that spinal orthoses affect erectorspinae muscle more than abdominal muscles21⁾. A rigid orthosis limits the movement of the spine by more than asoft orthosis. So, it is considered that a rigid orthosis affects a change in posturalcontrol in the sagittal plane by decreasing the activities of muscles surrounding the waste.These result will help to prepare baseline data providing related information with propermediation about wearing lumbosacral orthoses rightly. The limitations of this study includedthat there was no control group and a lack of diversity with respect to the experimentperiod. Also, the duration the subjects wore the orthoses was not controlled exactly, and itwas difficult to generalize. It is considered that prospective studies controlling the studyperiod and duration the orthoses are worn exactly and including a control group will beneeded on the utility of orthoses prescribed as a therapy method for patients with low backpain.

Acknowledgments

This paper was supported by the Sehan University Research Fund in 2016.

REFERENCES