Received : 2012. 10. 25 Reviewed : 2012. 11. 10 Accepted : 2012. 12. 12 A Study on Correlation between Power of Trunk Flexors, Extensors and Lumbar Lordotic Angle in Normal Adults Bo-Mi Choi, K.M.D. Jeong-Min Yi, K.M.D. Hyun-Soo Kim, K.M.D. Dept. of Korean Rehabilitation Medicine, College of Oriental Medicine, Dae-Jeon University Objectives : The purpose of this study was to investigate the correlation between lumbar lordotic angle and the power of trunk flexors, extensors in normal adults Methods : 34 normal participants participated in this study. Their lumbar lordotic angle(l1-s1 Cobb s angle and L1-L5 cobb s angle) was measured by x-ray taken on lateral direction, erect cross-arm position. And muscle power of trunk flexors and extensors of each participant measured using Cybex HUMAC NORM. Results : 1. The average of L1-S1 Cobb's angle was 47.21 8.88 and the average of L1-L5 Cobb s angle was 36.32 9.62 (Table ). 2. The average ratio of trunk flexors/extensors was 6.44 19.31%(Table ). The average power of the trunk flexors was 165.18 55.05 (Newton-Meter/kg), and the power of trunk extensors was 257.18 85.53 (Newton-Meter/kg)(Table ). 3. Lumbar lordotic angle has no relation to the ratio of trunk flexors/extensors(table, Fig. 4). 4. Lumbar lordotic angle has no relation to both the power of the trunk flexors and extensors(table, Fig. 5, Fig. 6). Conclusions : These results suggest that the lumbar lordotic angle measured by radiograph could not evaluate the power and ratio of trunk flexors, extensors. Keywords : Lumbar lordotic angle, Trunk flexors, Trunk extensors 39
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Fig. 1. L1-S1 Cobb s angle. Fig. 2. L1-L5 Cobb s angle. 41
< Fig. 3. Cybex HUMAC NORM(lateral & frontal view). 42
Table. Age and Sex of the Subjects Age (yr) 20 30 40 Total Male (N) 11 10 1 22 (64.70%) Female (N) 12 0 0 12 (35.30%) Total 23 (67.64%) 10 (29.41%) 1 (2.94%) 34 (100%) Table. Weight of the Subjects Weight (Kg) 40 50 60 70 80 90 Average : 65.56 13.68 N 5 8 7 11 1 2 Tatal : 34 Table. Height of the Subjects Height (Cm) 150 160 170 180 N 8 6 15 5 Average : 169.71 9.09 43
> > > > Table. L1-S1 Cobb s Angle and L1-L5 Cobb s Angle Average Minimum Maximum L1-S1 Cobb s angle( ) 47.21 8.88 27 63 L1-L5 Cobb s angle( ) 36.32 9.62 17 65 Table. Trunk Flexors/Extensors Ratio Average Minimum Maximum Flexors/ Extensors ratio(%) 66.44 19.31 117 37 Table. Trunk Flexors Peak Torque per Body Weight and Trunk Extensors Peak Torque per Body Weight Male Female Total Flexors (Newton-Meter/kg) 190.91 48.87 118.00 27.92 165.18 55.05 Extensors (Newton-Meter/kg) 281.91 86.97 211.00 63.16 257.18 85.53 44
> > > > Table Correlation Coefficient between Lumbar Lordotic Angle and Trunk Flexors/Extensors Ratio L1-S1 Cobb s angle L1-L5 Cobb s angle Flexors/Extensors ratio r-value -0.058 p-value 0.743 r-value -0.255 p-value 0.145 Fig. 4. Correlation coefficient between lumbar lordotic angle and trunk flexors/extensors ratio. 45
Table Correlation Coefficient between Lumbar Lordotic Angle and Trunk Flexors, Extensors Power Male Female L1-S1 Cobb s angle L1-L5 Cobb s angle L1-S1 Cobb s angle L1-L5 Cobb s angle Flexors power Extensors power r-value 0.140 0.093 p-value 0.533 0.679 r-value -0.098 0.069 p-value 0.665 0.759 r-value 0.012 0.018 p-value 0.970 0.957 r-value -0.016-0.070 p-value 0.961 0.828 Fig. 5-1. Fig. 5-2. Fig. 5. Correlation coefficient between lumbar lordotic angle and trunk flexors, extensors power in men. 46
Fig. 6-1. Fig. 6-2. Fig. 6. Correlation coefficient between lumbar lordotic angle and trunk flexors, extensors power in women. 47
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