| Objective Core stability training have been widely performed in rehabilitation.The former study shows that whole body vibration and Swiss ball training could improve the recovery for the patients with low back pain.The degree of core muscle activation is an important factor affecting core stability training,and seeking better training methods could guide the rehabilitation training.In addition,core stability training is often interfered by cognitive tasks,but there is no report on the effect of cognitive tasks on muscle activation during core stability training.The EMG was chosed to detect: 1)the effect of different vibration frequencies and exercise on muscle activation,for the purpose of seeking the best vibration frequency and exercise;2)the impact of different cognitive tasks and planes on core muscle activation during stability training.This study can provide scientific theory for the core stability training.Study 1 Effect of different vibration frequencies and types of exercise on core muscle activationMethod 23 health young people were chosed to complete the single bridge,prone bridge,lay-side bridge and crunch on the vibration training platform,and the non-vibration and the vibration frequencies 5 Hz,10 Hz and 15 Hz were performed respectively,with an amplitude of 2 mm.Using the surface electromyography to collect the muscle electrical signals including the right rectus abdominis,external oblique muscle,erector spinae and multifidus muscles,and the RMS of each muscle were analyzed on different conditions.The degree of muscle activation was calculated on different frequencies and exercises.Results(1)The EMG values of erector spinae muscle: there was an interaction between exercise and frequency(P<0.05).Seen from the frequency,there was a significant difference between each frequency,and the muscle activation was biggest at15 Hz.Seen from the exercise,there was significant difference at 10 Hz and 15 Hz(P<0.05).The result of post hoc analysis indicated that the highest muscle activation of erector spinae muscle is crunches with 15 Hz.(2)The EMG values of multifidus muscle: there was an interaction between exercise and frequency(P < 0.001).Seen from the frequency,there was a significant difference between each frequency(P< 0.001),and the muscle activation was biggest at 15 Hz.Seen from the exercise,there was significantly different at 15 Hz(P< 0.001).The result of post hoc analysis indicated that the highest muscle activation of multifidus muscle was observed in crunches with 15 Hz.(3)The EMG values of the rectus abdominis: there was an interaction between exercise and frequency(P< 0.05).Seen from the frequency,there was a significant difference between frequency(P< 0.05),and the muscle activation was biggest at 15 Hz.Seen from the exercsie,there was significantly different at 15 Hz(P< 0.05).The result of post hoc analysis indicated that the highest muscle activation of rectus abdominis was observed in single bridge with 15 Hz.(4)The EMG values of external oblique muscle: there was an interaction between different actions and frequencies(P<0.001).Seen from the frequency,there was a significant difference between frequency(P<0.05),there were not significant difference among the exercsies(P> 0.05).Conclusion Whole body vibration training can increase core muscle activation,and the vibration frequency increased within a certain range can activate more muscles,15 Hz was the biggest muscle activation frequency.There were different muscle activations among different exercsies.Single bridge and crunch are better training exercises for the lunbar and abdomen muscles.Study 2 Effects of cognitive-motor dual tasktraining on activation of core musclesMethod 36 college males to perform the supine bridge and the prone bridge on both the stable and unstable plane through the dual-task paradigms,at same time,non-cognitive tasks,simple cognitive tasks and difficult cognitive tasks were imposed during the exercises.Recording the surface EMG signals of the rectus abdominis,the external oblique,the erector spine and the multifidus muscle in each task,and then calculating the root mean square value of the EMG of each task,Root mean square(RMS)normalized to MVC(%)was calculated which reflect activity extent,and the effects of different plane and cognitive task difficulty levels on core muscle activation were analyzed by two-factor(plane* cognitive task)repeated measures analysis of variance.Results1 The EMG value of the Prone Bridge(1)The EMG value of erector spinae muscle: There was an interaction between the rectus abdominis in stable plane and cognitive tasks(P> 0.05).There is a main effect of plane(P< 0.001),and the unstable planes were higher activtion than the stable plane.There were no difference among cognitive tasks(P> 0.05).(2)The EMG value of multifidus muscle: There was no interaction between the plane and cognitive tasks(P> 0.05).There is a is a main effect of plane(P< 0.001),the activation on the unstable planes were significantly higher than the stable plane.The difference between the tasks were not significant(P> 0.05).(3)The EMG value of rectus abdominis muscle: There was an interaction between the plane and the cognitive task(P <0.05).There is a main effect of the plane(P< 0.001),the activation on the unstable planes were significantly increased compared to the stable plane.In the unstable plane,the difficult cognitive tasks were significantly decreased than non-cognitive tasks(P <0.05).(4)The EMG value of external oblique muscle:There was no interaction between the plane and cognitive tasks(P> 0.05).There is a main effect of the plane(P < 0.001),the activation on the unstable planes were significantly increased compared to the stable plane.In the unstable plane,the difficult cognitive tasks were significantly decreased than non-cognitive tasks(P< 0.05),and the simple task cognition was significantly decreased than the non-cognitive tasks(P< 0.05).Results 2 The EMG value of the Supine Bridge(1)There was no interaction between plane and cognitive load and exercise load(P>0.05).The difference between the two planes was not significant(P> 0.05),and there was a main effect of cognitive tasks(P< 0.05).On the stable plane,the cognitive tasks of difficult cognitive tasks were significantly dicreaseed than non-cognitive tasks(P<0.05).In the unstable plane,the difficult task was significantly decreased than the non-cognitive tasks(P< 0.05).(2)There was an interaction between the cognitive task and the plane on multifidus muscle(P< 0.05).The difference between the two planes was not significant(P> 0.05),There was a main effect of cognitive tasks(P< 0.001),the simple tasks on the stable plane were significantly less than the no tasks(P< 0.05),and the difficult tasks were significantly less than the non-cognitive tasks.(P< 0.05).On the unstable plane,the difficult task was significantly decreased than the non-cognitive tasks(P< 0.05),and the difficult task was significantly decreased than the easy tasks(P< 0.05).(3)There was no interaction between the cognitive and the stable plane on rectus abdominis muscle(P> 0.05).There is a main effect of the plane(P< 0.05).In the three groups of tasks,the activation on the unstable planes were significantly increased compared to the stable plane.There was no significant difference between the three tasks(P> 0.05).(4)There was no interaction between the plane and cognitive tasks in the external oblique muscle(P> 0.05).There is a main effect of the plane(P< 0.001),In the three groups of tasks,the activation on the unstable planes were significantly increased compared to the stable plane.The task of stabilizing plane complex was significantly less than that of no task(P< 0.05).Conclusion:In the core stability training,stable planes and cognitive tasks affect core muscle activation during stability training.The unstable plane increases the degree of muscle activation.Adding cognitive tasks will reduce the activation of the core muscle. |
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