Physical Examination Of Back Muscles Strength And Endurance And Its Correlation With Health-related Quality Of Life

Background and ObjectiveThe back muscles play an important role in maintaining the posture and spine balance of the human body.The literature believes that the degeneration of back muscles and the occurrence and development of degenerative spinal deformity(DSD)have a causal relationship,suggesting that the evaluation of back muscles function has important clinical significance for DSD research.Existing researches mainly focus on imaging analysis of morphological atrophy and fatness of the lower back muscles.However,physical examinations such as strength and endurance,which are more important in muscle function evaluation,have not been fully applied in back muscle function evaluation due to lack of suitable detection methods.Up to now,there is no literature report on the impact of back muscles strength and endurance level on the Health-related quality of life(HRQL)in patients with DSD,which restricts the scientific exploration of the pathogenesis of DSD and the resolution of a series of related clinical problems.In this research,we have developed a variety of devices for testing the function of the back muscles,exploring physical examination methods and technical indicators suitable for objective evaluation of the strength and endurance of the back muscles,and studying their impact on HRQL.By comparing the strength and endurance of the back muscles of DSD patients with healthy people,and the relationship with different dimensions of HRQL,to provide optimal methods for physical detection of the function status of back muscles and its impact on HRQL of DSD patients,further have important reference value for in-depth research on scientific and clinical issues such as the pathogenesis,clinical classification,prognosis assessment,functional rehabilitation and treatment choice of DSD.MethodsThis study was a prospective clinical study.After ethical review and clinical study registration,60 DSD patients were enrolled as the experimental group from May 2018 to July 2019,and 40 volunteers with normal spinal alignment during the same period w ere included as the control group.The sex,age,and body mass index of the two groups were matched.1.Use the isometric strength tests in standing,prone and sitting positions to evaluate the maximum isometric strength(MVE)of back muscles,and use the isometric endurance tests in standing and prone positions to evaluate the endurance time(ET)of back muscles,with an interval of 1 hour between each test,repeated after 7 days.The isokinetic strength test of the back and abdominal muscles was completed at angular speeds of 30 ° / s,60 ° / s and 120 ° / s,then peak torque(PT)and Flexion/Extension ratio(F/E)was recorded.Completed the isokinetic endurance test of the back muscles and abdominal muscles at 120 ° / s,and recorded the endurance ratio(ER)and F/E.Methodological reliability research was performed by intra-class correlation coefficient(ICC)and PT at 60 ° / s was used as the gold standard to validity the MVE of back muscles by pearson correlation.At the same time,the grip strength(GS)of both hands was measured and recorded.2.Collect HRQL scores,including Visual analogue scale(VAS),Roland-Morris questionnaire(RMQ),Oswestry Disability Index(ODI)and 36-item short form health survey(SF-36)of all subjects in a quiet condition.Two independent-sample t tests were used to compare the strength,endurance,and F / E of the back and abdominal muscles in two groups.The difference degree of each index between two groups was also calculated.3.Correlation analysis was used to study the relationship between unit weight of back muscles MVE(MVE / BW),unit weight of back muscles PT(PT / BW),ET,ER and HRQL scores,including VAS,ODI,RMQ,SF-36 and internal item scores.Statistical significance was set at 0.05.Results1.Methodological study: ICC values of MVE of back muscles in standing,prone,and sitting positions are 0.97,0.97,and 0.96,respectively(P<0.001).The correlation coefficients with isokinetic strength measurements are 0.60,0.48,and 0.37 correspondingly(P<0.01);The ICC values of ET of back muscles in standing and prone positions are 0.96 and 0.95,respectively(P<0.001).2.Comparative study between two groups: MVE in standing,prone,and sitting positions of the experimental group is significantly lower than that of the control group,and the differences are 26.5%,28.0%,and 18.1%,respectively;The prone ET in the experimental group is significantly lower than that in the control group and the difference is 38.5%,while there is no significant difference in the standing ET between the two groups;The PT of experimental group is significantly lower than that of the control group in isokinetic test with 30 ° / s,60 ° / s and 120 ° / s,the differences were 29.6%,34.1%,and 30.2% respectively;The PT of the abdominal muscles in the control group at different angular velocities were lower than those in the control group,and the differences were 16.8%,10.3%,and 11.2%,but there was no statistical difference;The F / E of the experimental group were between 1.1 and 1.5,while the F / E of the control group were between 0.9 and 1.1,the differences between the two groups were 22.2%-55.6%;There were no significant differences in GS of both hands and ER of back and abdominal muscles between the two groups.3.HRQL correlation analysis: MVE / BW in three positions,PT / BW in three angular velocity and ET in the prone position are significantly negatively correlated with ODI,and RMQ,and significantly positively correlated with SF-36.Standing MVE/ BW and PT / BW at 30 ° / s and 60 ° / s have the highest coefficient of determination on HRQL.In the experimental group,standing MVE / BW and PT / BW at 60 ° / s were moderately negatively correlated with ODI and RMQ,and moderately positively correlated with PF and RP in SF-36;In the control group,PT / BW at 30 ° / s of back muscles was moderately positively correlated with SF-36 and BP and RE in SF-36.Conclusions1.Isometric strength and endurance tests of the back muscles in different positions can effectively evaluate the function of back muscles.The isometric strength test in the standing position has the highest validity,and can be used as an optimal method for evaluating the strength of the back muscles.The isometric endurance test in prone position has high sensitivity and is a suitable method for detecting back muscle endurance.2.The strength and endurance of the back muscles of patients with DSD is significantly reduced,and the reduction of back muscle strength is significantly higher than that of abdominal muscles,which is the main cause of the imbalance of the trunk flexor and extensor muscles of patients.The back muscle dysfunction in patients with DSD is related to pathological factors rather than aging changes in the skeletal muscle system.3.Standing MVE / BW,PT / BW at low and medium angular velocity and ET in the prone position are closely related to HRQL.Among them,standing position MVE / BW and medium-speed PT / BW are significantly negatively correlated with dysfunction scores of DSD patients,and are significantly positively correlated with physiological function scores.They are suitable indicators for physical examination of back muscles to reflect their HRQL...