Introduction: Lower back pain is a common musculoskeletal disorder in nurses. Therefore, this study aimed to compare the effect of vibration therapy and that of muscle relaxation methods on nurses with low back pain.
Methods: In this clinical trial, 110 nurses with low back pain were randomly assigned to two intervention groups (group I and group II). The research instrument were written consent form, demographic questionnare, numeric pain rating scale and pain assessment flowsheet. In group I, the nurses received vibration therapy once a day for 10 minutes for two weeks. In the group II, the nurses performed muscle relaxation once a day for 20 minutes for two weeks. Then, pain rate was measured before and after the intervention in both groups. The data were analyzed by SPSS 20 and α =0.05 was considered significant.
Results: There were no significant difference between the two groups in terms of demographic information (p>0.05). Before the intervention, there was no significant difference between the the groups in terms of average low back pain (P = 0.0814). After the intervention, both groups experienced a statistically significant decrease in pain compared to that before intervention (p≤0.001). The nurses’ low back pain in the muscle relaxation group decreased from 5.8 to 4.25 and from 5.9 to 3.1 in the vibration therapy group. There was a significant difference between the groups in terms of the average  pain severity after the intervention (p=0.044) so that the pain reduction rate in the vibration therapy group was higher than that in the muscle relaxation group.
Conclusion: The results showed that vibration therapy and muscle relaxation reduced the nurses’ low back pain. In other words, both methods were effective. However, vibration therapy was more effective.

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