Study On Optimal Gluteal Muscle Intervention Strategy In Patients With Patellofemoral Pain Syndrome Before Functional Training

Objective: Abnormal proximal movement pattern is an important risk factor for Patellofemoral pain syndrome(PFPS),but strength training alone does not seem to solve this problem.Gluteal activation disorder has been found to be involved in functional activity in these patients and may be the underlying cause of abnormal hip motion.So the purpose of this study was to compare if patients with PFPS who perform gluteal activation training prior to functional exercises demonstrate sooner improvements on lower limb alignment than patients who perform hip strengthening prior to the same functional exercises,and achieve better overall improvements of pain and function,so as to optimize the treatment strategy for patients with PFPS.Methods: Thirty-six PFPS patients were randomly divided into two groups,eighteen for each group.The activation group and the strengthening group performed gluteal muscle activation training and hip muscle strength training for the first 4weeks respectively,prior to 4 weeks of a similar lower limb functional training.The intervention lasted for 8 weeks,3 times a week.Self-reported knee pain(VAS)and functional ability(Lower Extremity Functional Scale)were choosed as the primary outcome indicators.In addition,hip isometric strength and pelvic and lower extremity kinematics in the step down test were the secondary outcome indicators.Results:(1)The pain scores of both groups significantly improved after 4 weeks of intervention(P < 0.05),and further significantly improved after the end of intervention(P < 0.05),and also remained well during the follow-up test.(2)The scores of the LEFS of two groups were significantly improved after the intervention(P < 0.001),and the activation group significantly improved further during the follow-up test(P=0.048).(3)After 4 weeks of gluteal activation training,the activation group achieved the same level of muscle strength increase(15.4% increase in hip abductor isometric strength,70% increase in hip rotation isometric strength,P< 0.001)as the strengthening group,and well maintained until the end of the intervention and in the follow-up test.(4)In the step down test,pelvic and lower limb kinematics in the activation group improved compared with that in the strengthening group in the early time(after 4 weeks of intervention),including the increase of pelvic forward(P=0.046)and hip flexion(P=0.036)angles,as well as the tendencies of hip adduction and internal rotation angles decreasing,which were maintained until the follow-up test.Conclusions:(1)Gluteal activation combined functional exercise and hip strengthening combined functional exercise can both effectively improve pain and lower limb function in patients with PFPS,but the former showed a more positive follow-up effect.Specific gluteal muscle intervention strategy should be selected according to the specific situation of patients in clinical practice.(2)Compared with hip strengthening,gluteal activation training prior to functional exercise had an earlier positive effect on improving pelvic and lower limb movement patterns.(3)Gluteal activation training might promote neuromuscular recruitment in PFPS patients to achieve the same level of muscle strength growth as hip strengthening training,suggesting that clinical enhancement of proximal muscle in these patients should consider whether there is an activation disorder.