Study On The Characteristics Of Knee Muscle Strength In Runners With Patellofemorel Pain Syndrome (PFPS) Based On Isokinetic Technology

Objective:Explore the the differences of isokinetic muscle strength characteristics between runners in patients with patellofemoral pain syndrome(PFPS)and the normal runners and the relevance to Kujala scale,trying to discover whether isokinetic muscle strength characteristics can be used as runners PFPS preliminary diagnosis and formulate sports therapy evaluation reference.Methods:40 subjects were included in sports medicine in sichuan provincial orthopaedic hospital using isomed2000 isokinetic testing system to test the peak torque of quadriceps and hamstring measured under the concentric contraction and eccentric contraction mode,the angular velocity is 60 ° / s.Then we calculate its all kinds of torque ratio.At the same time,the total score was calculated on the subjective score of Kujala in PFPS patients.To analyze the difference between the PFPS group and the normal group,and the correlation between the patients’ flexion ratio and the total score in the PFPS group.Results:1.Comparison of the relative peak torque in the two groups :in the patients with unilateral PFPS,the strength of extensor flexor decreased.2.The ratio of peak torques in the two groups indicate:(1)The patients with unilateral PFPS were significantly different from the healthy side in Hc/Qc,Hc/Qe,He/Qc.(2)Hc/Qc: The ratio of affected side is larger than that of uninjured side,it indicates that on the affected side the extent of concentric contraction force of the quadriceps is lower than that of the hamstring.(3)Hc/Qe: The ratio of affected side is larger than that of uninjured side,it indicates that flexion of the knee joint,on the affected side the extent of eccentric contraction force of the quadriceps is lower than that of concentric contraction of the hamstring.(4)He/Qc: The ratio of affected side is larger than that of uninjured side,it indicates that extension of the knee joint,on the affected side the extent of concentric contraction force of the quadriceps is lower than that of eccentric contraction of the hamstring.3.The ratio of relative peak torques and peak torques in two group indicates: in the patients with unilateral PFPS,the lateral flexion knee muscle strength was lower than that of the normal patients,and the balance of flexor and extensor on the lateral side was abnormal.4.Kujala score and Hc: Qc,Hc: Qe,He: Qc all have negative linear relationship(r=-0.987,P =0;R = 0.924,P = 0;R =-0.453,P=0.042).Conclusion:1.the flexor and extensor between left and right lateral side of the normal runner’s knees is balanceable.2.Compared with the normal group,all the concentric contraction and eccentric contraction force of the quadriceps and harming decreased,it suggest that the targeted functional exercise was particularly important.3.The decrease of quadriceps muscle strength in PFPS patients was greater than that of the hamstring.4.In the functional evaluation of PFPS patients,the quadriceps and hamstrings of hamstrings and the related ratios should be considered.5.The ratio of each moment(Hc: Qc,Hc:Qe,He: Qc)can be used as a reference for the clinical diagnosis and efficacy of PFPS patients,and can be used to build a sports treatment plan for PFPS patients according to the torque ratio.