3 D Motion Analysis Sacrum Correction In Patients With Hemiplegia Balance Testing Application

Objective: To study the reliability and validity of sacral marker method inestimating the balance function of stroke patients with hemiplegia in standing andwalking.Method：Recruit21stroke patients with hemiplegia，and measure the Mean SwayAmplitude （MSA）and Mean Sway Velocity（MSV）of sacral marker with sacralmarker method and center of gravity of body with segmental method；use thesegmental method as the gold standard. Analyze the data using Bland-Altman plotswhich can obtain the95%limits of agreement (LOA)．Results：1. Test-retest reliability：The95%LOA of MSA in standing was (-4.42，5.14) in X axis，(-6.04，4.52) in Y axis，(-1.75，1.31) in Z axis;MSV was (-0.08，0.09) in X axis，(-0.10，0.08) in Y axis，(-0.03，0.02) in Z axis. The95%LOA ofMSA in walking was (-185.74，105.53) in X axis，(-22.57，2.7621) in Y axis，(4.43，2.76) in Z axis; MSV was (-3.10，1.76) in X axis，(-0.38，0.54) in Y axis，(-0.07，0.02) in Z axis.2．Validity：The95%LOA of MSA in standing was (-3.62，2.55)in X axis，(-3.95，3.94) in Y axis，(-7.35，19.43) in Z axis; MSV was (-0.06，0.04)in X axis，(-0.07，0.07) in Y axis，(-0.12，0.32) in Z axis. The95%LOA of MSA in walking was (-4.40，4.74) in X axis，(-17.35，4.14) in Y axis，(-17.35，4.14) inZ axis; MSV was (-0.07，0.08) in X axis，(-0.29，0.07) in Y axis，(-0.13，0.18) inZ axis.Conclusions：Sacral marker method can be used to assessing the balance of strokepatients in different states，and it has the applicable value in testing the balance ofstroke patients. Objective：To study the validity of sacral marker method on testing third-levelbalance performance.Method： Recruit health people (n=10)and brain injury patients withhemiplegia(n=11), both groups took the Postural Stress Test with external forceperturbation using the sacral marker method; the variables were Balance StrategyScores and Mean Sway Amplitude and Mean Sway Velocity of the Sacral Marker;and for hemiplegic patients we also took Berg Balance Scale and modified Timed“Up-and-Go” test.Results：1.In hemiplegic patients there were no correlation between balance strategyscores and the static component of Berg Balance Scale(rs=0.56)、the tests of thesecond-level balance state (the dynamic component of Berg Balance Scale(rs=0.56)、modified Timed “Up-and-Go” test(rs=0.07)（)P>0.05）;2.The Mean Sway Amplitudeand Mean Sway Velocity of the Sacral Marker negatively correlate with the BalanceStrategy Score(health people: rs=-0.76，rs=-0.77;hemiplegic patients: rs=-0.78，rs=-0.68).Conclusions：The character of third-level balance is different from the other twobalance performance.The Mean Sway Amplitude and Mean Sway Velocity of SacralMarker with sacral marker method and external force perturbation can reflect thethird level balance in health persons and hemiplegic patients，and the sacral markermethod can be applied to evaluate the third-level balance performance. Purpose：Use the sacral marker method to study the character of third-level balanceof health people and hemiplegic patients with brain injury applied withdifferent-direction external force perturbation.Method：Recruit10health people and10hemiplegic patients respectively. Exert theexternal force to the body in different directions and meanwhile record themovement of body with the Mean Sway Amplitude（MSA）and Mean Sway Velocity（MSV）of Sacral Marker.Results：In health people the back-direction force can cause the largest valuecompared with the other three directions in MSA and MSV，while there is nosignificantly different between the front-/left-and right-direction. In hemiplegicpatients the hemiplegic side force can cause the biggest value in MSA（MSA=20.72mm），and then the back-direction force in MSA（MSA=17.58mm），while there is no significant difference in front and non-affected side force（MSA=11.87mm、13.5mm）.Conclusions：When applying the external force to health people, the balancestability is weak in back-direction force; while the MSA in hemiplegic side force isbigger than other directions, so hemiplegic patients are easier to fall toward thehemiplegic side.