Scapular Kinematics And Functional Characteristics Of Scapular Muscles With Subacromial Impingement Syndrome And Exercise Intervention Study

Objective:The purpose of this study is to describe the related indexes of acromion-humeral distance,scapula position and scapular muscle function with subacromial impingement syndrome(SIS),and to analyze the changes of scapular kinematics and subacromial space during shoulder abduction,as well as the correlation between scapular muscle function and scapular kinematic changes,and between subacromial space changes,and take this as a guide for scapular muscle rehabilitation intervention.To provide theoretical and practical basis for scapular muscle rehabilitation training in the treatment of SIS.Part one:Analysis of subacromial space,scapular kinematics and functional characteristics of scapular muscles in patients with subacromial impingement syndrome.Methods:50 sports population with SIS and 25 healthy controls were selected as subjects.The acromio-humeral distance(AHD),the scapular kinematic characteristics and activation,muscle strength and flexibility of scapular muscles were compared between patients with SIS and healthy controls by ultrasound,radiography and surface electromygraphy.The effects of scapular muscles on scapular kinematics and AHD during shoulder abduction were observed.Results:(1)During shoulder abduction from 30°to 60°,the decrease of AHD in SIS group was greater than that in normal group(P<0.05),in the process of shoulder abduction 0°to 60°,the decrease of AHD in SIS group was also large than that in normal group(P<0.05);(2)When shoulder abduction was 60°,the scapular upward rotation parameter SURA of SIS group was significantly lower than that of normal group(P<0.05),and the CUSD value of shoulder abduction 90°was lower than that of normal group(P<0.05).there was no significant difference in LSS which is the parameters of internal and external rotation angle of scapula between the SIS group and the normal group;(3)The standardized maximum isometric contractile strength of UT,MT,LT and SA,the activation of MT,LT and SA during shoulder abduction and PMI in SIS group were lower than those in normal group(P<0.05),and the activation of ut in SIS group was higher than that in normal group(P<0.05);(4)AHD_30°-60°was correlated with the muscle strength of MT and LT(|r|>0.4,P<0.05),and with the activation of MT and LT(|r|>0.3,P<0.05).SURA_0°-60°was correlated with the muscle strength of UT,MT and LT(|r|>0.3,P<0.05).CUSD _0°-60°was correlated with SA muscle strength(r=0.503,P<0.05)and SA activation(r=0.333,P<0.05),LSS_0°-60°was correlated with MT activation(r=0.306,P<0.05),SURA_0°-90°was correlated with UT and MT muscle strength(|r|>0.3,P<0.05)and UT and LT activation(|r|>0.3,P<0.05).The CUSD with 90°shoulder abduction was correlated with PMI(r=0.446,P<0.05).Part two:Study on the effect of rehabilitation training of scapular muscle in with subacromial impingement syndrome.Method:45 SIS subjects were randomly divided into exercise group and control group,the control group received health education intervention,and the exercise group received health education and targeted scapular muscle rehabilitation training intervention,intervention lasts for 8 weeks.Targeted scapular muscle group rehabilitation training intervention program based on the characteristics of scapular muscles dysfunction found in“Part one”,using targeted scapular muscles rehabilitation training program of exercise intervention for SIS patients,3 times a week,a total of 24 times.The pain and shoulder function score,shoulder range of motion,AHD,kinematic parameters of scapular,and strength and activation of trapezius muscle and serratus anterior muscle,as well as PMI,were measured before and after rehabilitation training/education.Results:After 8 weeks of rehabilitation intervention/health education,there were 3 cases falling off,2 cases in the exercise group and 1 case in the control group:(1)In the exercise group,the scores of pain and joint function decreased(P<0.05),shoulder flexion angle abduction angle abduction angle increased(P<0.05).In the control group,there was no significant change in pain and joint function scores(P<0.05),shoulder abduction angle increases(P<0.05),shoulder abductor strength did not change significantly(P<0.05).(2)In the exercise group,the AHD of abduction at 60°and AHD _0°-60°increased,shoulder,SURA increased at 90°abduction,CUSD increased at 0°,60°,90°abduction(P<0.05).There was no significant change in AHD and scapular kinematic parameters in control group.(3)In the exercise group,the muscle strength of MT,LT and SA were significantly improved,the activation ratio of UT/MT,UT/LT and UT/SA decreased,and the pectoralis minor muscle index increased(P<0.05).There was no significant change in the function index of the above-mentioned scapular muscles in the control(P>0.05).Conclusion:(1)During shoulder abduction from 30°to 60°and from 0°to 60°,the subacromial space in sports population with subacromial impingement syndrome reduced more than that in normal subjects,and the increase of subacromial space is related to weak MT and LT strength,and is related to insufficient activation of weak MT and LT strength and insufficient activation of MT and LT during shoulder abduction.Serratus anterior muscle and pectoralis minor muscle play an important role in controlling the scapula posterior during shoulder abduction.(2)Sports population with subacromial impingement syndrome show scapular upward rotation and Posterior decrease.During early stage of shoulder abduction(0°to 60°),scapular posterior may play a more important role in maintaining the subacromial space.(3)The scapular muscles rehabilitation training can reduce the pain and symptoms of patients with subacromial impingement syndrome,improve joint function,increse scapular upward rotation and posterior and increase the subacromial space at 60°shoulder abduction.