Effects Of Hot Compress Combined With Low-Medium Frequency Electrotherapy On Pain,Proprioception,and Dynamic Stability Among Knee Osteoarthritis

Objective:Knee osteoarthritis（KOA）is one of the prevalent chronic degenerative diseases among older adults and is one of the leading causes of mobility and even disability among older adults.The clinical symptoms of KOA are mainly pain,decreased proprioceptive and dynamic stability.As the disease progresses,KOA will seriously affect the physical function,quality of life and social function of the older adults,which has a significant impact on patients,families and society and a heavy economic burden.However,there is no complete cure for KOA,and the current management goals for KOA are primarily to relieve patients’clinical symptoms and maintain or improve their mobility.Hot compress is the most commonly recommended physical factor treatment,are already widely used to relieve pain in KOA patients,but there is room for further improvement in improving physical function in KOA patients.Low-medium frequency electrotherapy has the potential to improve proprioception and dynamic stability by applying electrical stimulation to the skin surface.Hot compress combined with low-medium frequency electrotherapy may provide complementary advantages to further improve pain,proprioception and dynamic stability in older adults with KOA,and promote comprehensive recovery in KOA patients.However,as far as we know,no studies have been done.Therefore,the purpose of this study was to explore the difference of rehabilitation effect of single or combined intervention on older adults with KOA from pain,proprioception and dynamic stability through single hot compress intervention or combined intervention of hot compress combined with low-medium frequency electrotherapy for 8 weeks,in order to provide safer and effective rehabilitation treatment for older adults with KOA.Methods:A total of 34 older adults with knee osteoarthritis were recruited for this study and randomly divided into the combination treatment group and hot compress group,with 17 patients in the combination treatment group and 17 patients in the hot compress group.In this study,only hot compress treatment was performed in the hot compress group,and hot compress combined with low-medium frequency electrotherapy was performed in the combination treatment group,lasting for a total of8 weeks,three times a week for 40 min each time.Finally,a total of 29 participants completed the experiment,including 15 in the combination treatment group and 14 in the hot compress group.Pain scores,proprioception,and dynamic stability tests were administered to all participants at two-time points,week 0（pre-intervention）and week9（post-intervention）.The pain subscale in the Western Ontario and Mc Master Universities Osteoarthritis Index（WOMAC）was used to assess the degree of knee pain of the affected leg,the motion perception threshold of knee flexion and extension of the affected leg was evaluated by a proprioceptive tester（Sunny,Jinan,Shandong,China）,the position perception error values of the affected knee at 15°,45°,and 75°were evaluated by a joint protractor（Zimmer Ltd,Blackpool,UK）,and kinesthetic and kinetic indicators of the affected leg were collected by a twelve-camera motion analysis system（Vicon,Oxford Metrics Ltd.,UK）and two force platforms（90*60*10 cm,AMTI,BP600900,USA）.Statistical analysis of pain scores,proprioceptive,and dynamic stability indicators was performed using a two-way repeated ANOVA.Results:The Shapiro-Wilk test showed that all variables were normally distributed.There were no significant differences in Kellgren/Lawrence radiographic grade（p=0.972）,sex（p=0.597）,age（p=0.815）,weight（p=0.842）,height（p=0.613）,and body mass index（p=0.520）between the two groups of participants.After eight weeks of intervention,significant interactions were detected in the WOMAC pain score（p=0.041,η_p²=0.146）,45°（p=0.047,η_p²=0.138）and 75°（p=0.012,η_p²=0.213）position perception error of knee joint,the velocity of the center of mass in the medial-lateral direction at the moment of the heel(vCoM_ml,p=0.043,η_p²=0.144),the margin of stability(MoS_ml,p=0.011,η_p²=0.217)and the center of pressure displacement(CoP_ml,p=0.040,η_p²=0.147)in the medial-lateral direction at the moment of toe off the ground.Post Hoc tests were performed showing that compared to pre-intervention,after the intervention,the WOMAC pain score（p<0.001,d=2.410）,and 45°（p=0.007,d=0.844）and 75°（p=0.004,d=0.746）position perception error of knee joint were significantly decreased,the vCoM_ml at the moment of heel contact（p=0.015,d=0.443）was significantly increased,the MoS_ml at the toe off the ground（p<0.001,d=1.117）was significantly decreased,and CoP_mlat the toe off the ground（p<0.001,d=1.069）was significantly in the combination treatment group;the WOMAC pain score（p<0.001,d=2.033）was significantly decreased in the hot compress group.After the intervention,the WOMAC pain score（p<0.001,d=1.901）in the combination treatment group was lower than those in the hot compress group.Conclusion:Compared with the hot compress,the hot compress combined with low-medium frequency electrotherapy for eight weeks was more effective in improving pain,proprioception,and dynamic stability among older adults with KOA.Therefore,it is recommended that hot compress therapy should be followed by low-medium frequency electrotherapy to promote the comprehensive rehabilitation of KOA patients.