Background:The application of high field strength T2 relaxation time can serve as an effective and non-invasive indicator to evaluate structural changes in the lumbar muscles. So, how
exactly to measure about high field strength under normal lumbar muscle tissue T2 relaxation time? How did T2 values change after the training? The purpose of this study was to analyze normal human
lumbar muscles T2 relaxation time values after inertial barbell training.
Methods:Thirty undergraduate healthy males (mean age 19 ± 1.2 years old, mass 72 ± 10.0Kg, body height 1.78 ± 0.1 m), were recruited to participate in this study. They were randomly
divided into two groups: inertial barbell training group (IBTG)(15 males) and normal barbell training group(NBTG) (15males); All participants were conducted 1 hour / time, 3 times / week, a total of
eight weeks of the lumbar flexion and extension muscle strength training. Before and after the experiment, they were asked to sustain quietly supine position at resonance, using 3.0T superconductive
magnetic resonance imaging system (Siemens Magnetom Trio, Tim System), to scan the lumbar of participant respectively. Data were analyzed using the Statistical Package for the Social Sciences (version
15.0;IBM Inc., Chicago, IL). Measures of reliability are presented as intraclass correlation coefficients of absolute agreement for single measures. Within- and between-group differences were assessed
by paired samples T-test and two independent samples T test respectively. Significance for all tests was defined as P = 0.05, very significant standards as P <0.01.
Results:Before the test the mean ICC values of reliability of IBTG was 0.996, 95% confidence interval (0.948,0.999); after the test mean ICC was 0.998 (95% CI) (0.993,0.999) , p<0.01.
Before the test the mean ICC values of reliability of NBTG was 0.997 (95% CI) (0.983, 0.999); after test mean ICC was 0.994 (95% CI) (0.966, 0.999), p<0.01. Before and after the test both the IBTG and
the NBTG T2 values had a very significant difference (p = 0.000 <0.01) within-group; there was no significant difference between-group (before test P = 0.45> 0.05 and after test P = 0.17> 0.05). But △
T2 between-group had a very significant difference (p = 0.002 <0.01); △ T2 / T2 percentage, the IBTG also had a very significant difference (p = 0.009 <0.01).
Conclusions:This study demonstrated that eight weeks of strength training led to significant improvements in the T2 relaxation time values of lumbar muscles. Furthermore, these
results indicate that △ T2 / T2 percentage of IBTG has a higher change than the NBTG, which suggests lumbar muscle activity had better increased in the inertial barbell training.