Abstract: BACKGROUND: Low-load compression training of the extremities can produce muscle hypertrophy in the extremities, but whether the training can exert a positive effect on the core muscles is rarely reported.
OBJECTIVE: To explore the effects of low-load compression training of the extremities on the surface electromyography and isokinetic flexor and extensor strength of core muscles, aiming to provide theoretical basis for sports rehabilitation training for people who need to improve core muscle strength.
METHODS: Sixteen college students were divided into a compression group (n=8) and a control group (n=8) according to a random number table. In the compression group, three sessions of five training actions with 25% 1RM were performed under the condition of extremity compression. Low-load training was performed in the control group. After 7 weeks, the changes in surface electromyography and isokinetic muscle strength were compared between two groups. The study protocol complied with the Declaration of Helsinki and the relevant ethical requirements of Chengdu Sport University. Each subject was voluntary to participate in the trial and fully informed of the trial process.
RESULTS AND CONCLUSION: After trunk flexion training, the root mean square of surface electromyography signal of the rectus abdominis and external oblique muscles in the compression group was significantly different from those before training as well as those in the control group after training (P < 0.05). After trunk stretching training, the root mean square of surface electromyography signal of the erector spinae and multifidus muscles in the compression group was significantly different from those before training and those in the control group after training (P < 0.05). After standing leg stretching training, the root mean square of surface electromyography signal of the erector spinae and multifidus in the compression group was significantly different from those before training and those in the control group after training (P < 0.05). After bench press and sitting knee extension training, there was no significant difference in the root mean square of surface electromyography signal of core muscle groups (P > 0.05). In the compression group, the trunk flexor and extensor peak torque tests at the test angles of 30, 90 and 120 (°)/s were significantly different from those before training (P < 0.05). To conclude, the 7-week regular low-load compression training of the extremities can build the core muscles.

Key words: compression training, core muscles, trunk isokinetic strength, surface electromyography, exercise