Objective :
To investigate the correlation between torque onset angle of isokinetic knee test in paretic side and gait performance in subacute stroke patients.
Method :
A total of 102 subjects’ medical records were retrospectively reviewed. Hemiplegic patients were included in this study, who have been diagnosed with hemorrhagic or ischemic supratentorial stroke. We included (1)patients whose post-onset duration is less than 6 months and (2)patients who were able to take a isokinetic test properly(Korean version of the Mini-Mental State Examination, K-MMSE ≥24). And we excluded (1)patients whose motor grade of hip and ankle by manual muscle test were less than 3/5, (2)patients who have ataxia (3)patients who have any other brain lesion or musculoskeletal disease and (4)patients who have severe osteoporosis or uncontrolled medical problem. The parameters of gait performance were measured with the berg balance scale(BBS), the sub-score of BBS(sBBS, 11.turn 360 degrees and 12. placing alternate foot on step or stool while standing unsupported), time up and go time(TUG), 10m walk test time(10m WT), functional independence measure(FIM) and sub-score of FIM(sFIM, transfer and locomotion). And we use values of the second isokinetic test of knee such as peak torque, peak torque to weight ratio, Hamstring/Quadriceps ratio, torque onset angle(TOA), torque stop angle(TSA), torque at 30 degree(T30) and asymmetry ratio of peak torque between paretic limb and non-paretic limb. TOA is the first detected point of torque and TSA is the last measured point of torque in the moment angle position(MAP) curve. We use HUMAC NORM® as isokinetic dynamometer. Correlation coefficient and linear regression coefficient were used to analyze the correlation between onset torque angle and gait performance.
Results:
Baseline characteristics of the enrolled patients are presented in Table 1. TOA at paretic limb showed significantly higher correlations with BBS, sBBS, TUG, 10m WT, sFIM than other isokinetic parameters(Table 2) and also had high correlations with gait performance in partial correlation analysis adjusted by sex, age, height, weight, Body Mass Index(BMI) , MMSE, onset duration and spasticity. Simple regression analysis performed with paretic limb and asymmetry variables showed a linear relationships similar to Pearson’s correlation analysis. In multiple regression analysis, only TOA remained significantly associated with gait performance parameters(BBS, sBBS, TUG, 10m WT, sFIM ) except FIM. (Table 3)
Conclusion:
This study demonstrated that the torque onset angle is more predictable parameter to evaluate gait performance than peak torque. And we suggested that the potential to recruit muscle fiber quickly is more important than maximal strength in gait and dynamic balance function. |
