The Effect of Inertial Barbell Training on Lumbar Muscles Biomechanical Property
|School||Shanghai Institute of Physical Education|
|Course||Human Movement Science|
|Keywords||Inertial Barbell T2relaxation time Magnetic ResonanceImaging (MRI) Cross-sectional Area Lumbar Muscles Core Strength Biomechanical Property|
ObjectiveThe purpose of this study was to investigate the effectiveness andmechanism of inertial barbell training on biomechanical property of lumbarmuscles. Whether or not the inertial barbell can be used as a new type ofsports equipment, which can be play a beneficial role in lumbar musclesmorphology, function. This study will provide theoretical supporting for thesubsequent product improvement and the same products development.MethodsThirty healthy male undergraduates of Shanghai University of Sportvolunteered to participate in this study, there is no history of spinaldeformity and damage, no other sport injuries, such as the body withoutmetal stents male, and there is no history of professional sports training.They were randomly divided into two groups: experimental group--inertiabarbell training, the control group--conventional barbell training. Bothinterventions were conducted1hour per time,3times/week, for a total of8weeks, training lumbar flexion and extension. In the east China normaluniversity, Shanghai key laboratory of magnetic resonance imaging (mri)we used a3.0T superconducting magnetic resonance imaging system(MAGNETOM for any partial or Tim, Germany’s Siemens), to test lumbarmuscles morphology; In Shanghai sports institute, the ministry of educationkey laboratory, the biological Pressure Feedback is used (STABILIZER Pressure Bio-Feedback, the United States), according to the instructions ofthe Feedback instrument, to test transverse abdominal muscle andmultifidus activity; According to the "Bunkie" test method, the lumbarmuscles endurance has been tested; According to the CONTREXapplications training instrument the maximum moment of centripetalcontraction of torso flexion has been tested under the velocity of isometriccontraction,60°/s,150°/s; Using the KISTLER three-dimensionalplatform (Swiss KISTLER company,9287B), the sampling frequency is1200Hz, we explored the three-dimensional force and torque test.Results1. According to the3.0T superconducting magnetic resonance imaging(MRI),acquisition of lumbar muscle morphological results are as follows：(1) Before the testing, there was no significant difference (L41, P=0.27>0.05; L42, P=0.26>0.05) on the L4horizontal lumbar musclescross-sectional (CSA) of experimental group and control group; AfterTraining, the lumbar muscle CSA results of the two groups also had nosignificant difference (L41, P=0.19>0.05L42, P=0.18>0.05). But△CSA (the CSA of after the experiment measure-the CSA of before theexperiment measure) of L41, L42have very significant difference (p=0.000<0.01). Before and after the experiment, the data of L41CSA andL42CSA of experimental group and control group, are very significantdifference (p=0.000<0.01); After experiment， the△CSA%(△CSA%=(the CSA of after measurement–the CSA of before measurement/theCSA of before the measurement) it has a very significant difference (p=0.000<0.01) between the experimental group and control group.(2) The comparison of muscle volume were very significant difference (p= 0.000<0.01)within experimental group and control group before and afterthe experiment; There was no significant difference between two groupsmuscle volume value (P=0.26>0.05) before training; After training, therealso was no significant difference (P=0.19>0.05) between two groupsmuscle volume value; But after training, between group△V(△V=themuscle volume value after experiment-the muscle volume value beforeexperiment),△V%(△V%=(the muscle volume value after experiment-the muscle volume value before experiment)/the muscle volume valuebefore experiment) have a very significant difference (p=0.000<0.01).(3) The comparison of T2values were very significant difference (p=0.000<0.01)within experimental group and control group before and after theexperiment; There was no significant difference between two groupsmuscle T2values (P=0.45>0.05) before training; After training, therewas also no significant difference (P=0.17>0.05) between two groupsmuscle T2value, but△T2(the T2of after–the T2before the experimentmeasure),△T2/T2%results are very significant difference(P valuerespectively, P=0.002<0.01; P=0.009<0.01).2. According to the biological feedback pressure meter test the transverseabdominal muscle, multifidus activity results are as follows:(1) Before experiment, there was no significant difference (P=0.48>0.05)on the muscle pressure value of the transverse abdominal muscle andmultifidus between control group and experimental group; Before and afterthe experiment, the muscle pressure value of control group, experimentalgroup is very significant difference (P value in the group, respectively (P=0.004<0.01; P=0.000<0.01); After the experiment, muscle pressurevalue is significant difference between control group and experimentalgroup (P=0.048<0.05). The increase of the mean pressure is significant difference (P5=0.02<0.05) between the two groups during before andafter the experiment.(2) Before the experiment， there was no significant difference (P=0.23>0.05) of the pressure value between the control and experimental group;Before and after the experiment, the pressure value is very significantdifference (P value in the group, respectively, P=0.001<0.01; P=0.000<0.01) within Control and experimental group; After the experiment, thepressure value is significant difference(P=0.03<0.05) between the controland experimental group; After the experiment, the increased mean pressurevalue is significant difference(P=0.01<0.05)between the control andexperimental group.3. According to the "Bunkie" test method, the results are as follows:Before the experiment, in the supine position R/L and prone position R/L,there was no significant difference (P value of P=respectively.21, P=.34,P=.08, P=.31) of various posture test values between control andexperiment group; After the experiment, there was also no significantdifference(P value of P=respectively.21, P=.37, P=.27, P=.26) betweentwo groups; Before and after the experiment, but the test values is verysignificant difference (P value for P=.00) under various posture movementwithin each group. After experiment, each position increased percentagewere also no significant difference (P value of P=respectively.46, P=.09,P=.29, P=.15) between two groups; But the mean value percentage ofexperimental group were greater than the control group.4. According to the CONTREX training instrument, the centripetalcontraction results of trunk flexion under isometric contraction,60°/s,150°/s condations are as follows:Before experiment, there was no significant difference (P value respectively, P=0.10; P=0.20; P=0.38; P=0.40; P=0.41; P=0.15) of maximumtorque of the torso centripetal contraction under the isometric,60°/s,150°/s speed, between the experimental and control group; Before and afterexperiment， in comparison of the maximum moment were very significantdifference (P=0.00) within each experimental and control group; Aftertraining, the comparison of maximum moment between groups under the60°/s speed is very significant difference (P=0.00), the comparison ofmaximum torque were significant difference (P value respectively, P=0.03,0.03,0.03,0.04,0.02) under the rest each speed. Comparison before andafter the experiment isometric,60°/s、150°/s, the increased maximumtorque percentage is very significant difference (P=0.02) under the150°/sspeed. The others all have no significant difference. But except for theisometric contraction, the increased maximum torque percentage is less thanthe control group, the others speeds were greater than the control group.5. According to application of KISTLER, the results of thethree-dimensional force and torque are as follows:In the different load of inertia pendulum, the following pattern presents:with the increase of inertia pendulum weight, the force of Fxmax, Fzmaxdirection and the mean Mymax of all the participants linearly increased. Theforce of Fzmax increased significantly than the others; The faster load pointof changing of the force of Fxmax, Mymax appeared earlier than Fzmax.Conclusions1. Compared with normal Barbell training, inertia barbell training has biggereffect to lumbar muscles muscle cross section area and muscle volumeincreasing.2. The△T2/T2value of Inertial Barbell group was significantly higher than normal Barbell group, indicating lumbar muscles activity of InertialBarbell training is larger than normal Barbell training.3, Inertial Barbell compared with normal Barbell training, the activity oftransverse abdominal muscle and multifidus is larger than normal Barbelltraining; Inertial Barbell training caused abdominal muscle enduranceenhancement, indicating that it has certain benefits for core stability; Intraining, the effect level of lumbar muscles flexion and dynamic mechanicsof the Inertial Barbell increased. Thus it indirectly proves that the InertialBarbell training has better effect for lumbar abdominal strength trainingthan normal Barbell training.4. Through a variety of means of evaluation of the Inertial Barbell trainingeffect, we tried to build a preliminary evaluation system of sportsbiomechanics, which supporting for further development of product, and toprovide theoretical supporting.