| Objective: To measure part of the functions of the badminton players with low back pain in order to observe the scope of activities, muscle strength, myoelectricity activity and corresponding symmetry for the purpose of providing scientific basis for understanding the injury mechanism of badminton players. Subject: 6 badminton players with low back pain (4 males and 2 females). Method: Muscle activity tests were arranged for JOA rating scale, body rotation, thoracic spinal rotation, internal and external rotation of hip joint, constant speed rotation strength and isomeric back stretch activity. To observe the average value of the bilateral difference ratio. Result: The mean difference ratios of body rotation, thoracic spinal rotation and internal and external rotation of hip joint （31.98%±21.53%,19.8%±17.08%,13.81%±4.43%）are over 10% and only the mean difference ratio of the internal rotation of hip joint （5.62%±5.63%）is smaller than 10%. And the rotation activity of the thoracic spinal and hip joint tends to decrease. There is no significant difference between the bilateral peak torque of constant speed body rotation and mean power. The mean peak torque difference（5.45%±1.78%） is smaller than 10%. And the mean difference ratio of the average power （12.78%±11.40%）is over 10%. In the activity of isomeric back stretch, the mean bilateral difference ratio of the myoelectricity activity of erector spinae（14.18%±9.84%）is over 10%. While the mean bilateral difference ratio of the myoelecricity activity of multifidus muscle （9.90%±7.92%）is close to10%. The median frequency slope (MFs) of erector spinae and multifidus muscle tends to decrease, but the bilateral difference ratio （4.68%±3.17%，5.35%±5.40%）is smaller than 10%. Conclusion: (1) There is a problem of symmetry in the body rotation, thoracic spinal rotation and external rotation of hip joint of the badminton players with low back pain. And the rotation of thoracic spinal and hip joint tends to decrease. (2) There is a problem of symmetry in the mean power of constant speed body rotation. (3) During the test of isomeric back stretch, the fatigue of erector spinae and multifidus muscle is observed. So there is a problem of symmetry in myoelectricity activity. |
