The Effect Of Sensory Discrimination Training On Tactile Acuity For Patients With Chronic Low Back Pain

Background: Chronic low back pain(CLBP)has become one of the major health problems worldwide and is also one of the leading causes of disability worldwide.Primary and secondary somatosensory cortex reorganization in patients with CLBP has been confirmed,and the normalization of somatosensory cortex is considered to be a feasible goal for the treatment of pain,tactile acuity and the ability of motor control.In recent years,sensory discrimination training(SDT)has become an emerging method for treating cortical reorganization and training tactile acuity,which has attracted widespread attention in improving tactile acuity,physical function,and reducing pain in patients with chronic pain.But whether SDT can improve pain and tactile acuity in CLBP patients is still being studied.Based on this,this study uses a cross-sectional reliability and correlation study and a longitudinal intervention comparison study to reveal the effect of SDT on tactile acuity and pain in CLBP patients,providing a theoretical reference for the clinical application of SDT in chronic low back pain.Study 1 Study on the reliability and characteristics of sensory test in normal and chronic low back pain subjectsObjective:Two-point discrimination(TPD),point-to-point test(PTP),and two-point estimation(TPE)are commonly used to assess lumbar tactile acuity,while pain and age are two important factors affecting tactile acuity.The aim of this study was to investigate the intra-and inter-rater reliability of three measurements for painful and pain-free sides in normal people and CLBP patients of different ages,and the correlation factors of tactile acuity in CLBP patients.Methods:We recruited 30 normal subjects and 60 CLBP patients.According to population differences,90 subjects were divided into normal group and chronic low back pain group.According to age differences,60 CLBP subjects were divided into a young CLBP group(18 ≤ age ≤ 35,Y-CLBP)and an old CLBP group(36 ≤ age ≤ 65,O-CLBP).In the end,90 subjects were divided into a normal group,a Y-CLBP group and an O-CLBP group,with 30 people in each group.Two testers performed TPD,PTP,and TPE tests on 90 subjects within the same day(10 min interval),and one of the testers repeated the assessment program 24 h later.TPD includes two-point discrimination test was carried out in an ascending manner(A-TPD)and two-point discrimination test was carried out in a descending manner(D-TPD).The intraclass correlation coefficient(ICC)was used to assess the reliability.Pearson correlation coefficient was used to analyze the correlation factors of tactile acuity in patients with CLBP.Results: In normal group,the intra-rater reliability(ICC range: 0.78-0.90)and inter-rater reliability(ICC range: 0.75-0.87)of the TPD,PTP,and TPE on the left and right sides of the lumbar vertebrae 5(L5)level were all good.In the Y-CLBP group,the intra-rater reliability of TPD,PTP,and TPE on the painful and pain-free sides was good(ICC range: 0.74–0.85),while the inter-rater reliability of TPD,PTP,and TPE on the painful and pain-free sides was moderate to good(ICC range: 0.65–0.76).In the O-CLBP group,the intra-rater reliability of TPD,PTP,and TPE on the painful and pain-free sides was good(ICC range: 0.75–0.85),while the inter-rater reliability of TPD,PTP,and TPE on the painful and pain-free sides was moderate to good(ICC range: 0.70–0.85).In CLBP group,age,waistline,duration of pain,maximum pain,general pain and unpleasant score caused by pain were positively correlated with tactile acuity thresholds(D-TPD,A-TPD,PTP,TPE)(r > 0.365,p< 0.05).Conclusion: In normal subjects and CLBP patients,TPD,PTP and TPE are reliable methods to measure the tactile acuity in L5 level area.The tactile acuity threshold of painful side is higher than that of pain-free side,and the tactile acuity threshold of O-CLBP group is higher than that of Y-CLBP group and normal group.There was a positive correlation between tactile acuity threshold and age,waistline and pain related variables in CLBP group.Study 2 The effect of sensory discrimination training on tactile acuity for patients with chronic low back painObjective: The purpose of this study was to investigate the effect of sensory discrimination training on tactile acuity in patients with CLBP.Methods: Forty CLBP patients were randomly divided into the SDT group(n=20)and control group(n=20).The SDT group received a single sensory discrimination training,and the control group rested during the same intervention period.Before and after the intervention,tactile acuity(including TPD,PTP and TPE)thresholds and pain intensity on painful side and tactile acuity thresholds on pain-free side were measured.The changes of tactile acuity threshold and pain intensity(measured by numerical rating scale,NRS)before and after intervention were compared between the two groups.Results:After patients received a sensory discrimination training,the tactile acuity threshold,pain and unpleasant scores were significantly reduced in the painful side of the SDT group(D-TPD: t = 3.804,p = 0.001;A-TPD: t = 3.231,p = 0.004;PTP: t = 2.777,p = 0.012;TPE: t = 2.215,p= 0.039;NRS at present: t = 3.249,p= 0.004;NRS unpleasant: t = 3.559,p = 0.002).The D-TPD threshold of the SDT group after intervention was significantly lower than that of the control group(t =-2.198,p = 0.034).In the SDT group,the post-test tactile acuity thresholds of pain-free side were lower than that in the pre-test,and the D-TPD and A-TPD thresholds were significantly reduced(D-TPD: t = 2.677,p = 0.015;A-TPD: t = 2.174,p = 0.043).The post-test values of D-TPD,A-TPD,PTP,and TPE in the SDT group were lower than those in the control group,but there was no significant difference between the two groups after intervention on the pain-free side(p > 0.05).Conclusion: The Single treatment of sensory discrimination training can improve the tactile acuity and reduce pain in patients with chronic low back pain,and the treatment effect of painful side is better than that of pain-free side.