• Sajadi N
• Bagheri R
• Amiri A
• Maroufi N
• Shadmehr A
• Pourahmadi M

• Affiliation / Iran University of Medical Sciences and Health Services. School of Rehabilitation Sciences. Department of Physiotherapy
• Affiliation / Semnan University of Medical Sciences. Neuromuscular Rehabilitation Research Center
• Affiliation(G) / Iran / Semnan
• Affiliation(G) / Iran / Tehran
• Chronic Pain
• Flexion
• Low Back Pain
• Lumbar Vertebrae
• Physical Therapy Modalities / instrumentation
• Proprioception
• Vibration / therapeutic use

OBJECTIVE: This study aimed to evaluate the effect of high and low frequency of whole body vibration (WBV) on repositioning error in 3 different angles of lumbar flexion in patients with chronic low back pain.

METHODS: Twenty-four participants with chronic low back pain, aged between 20 and 35 years, were included in this randomized crossover trial study. Participants were randomly assigned into 2 groups as follows: (1) low frequency/high frequency, and (2) high frequency/low frequency. Participants received high-frequency (50 Hz) and low-frequency (30 Hz) WBV in a semi-squat position for 5 minutes in 2 sessions, with 2 weeks of rest. Before and after the WBV, lumbar repositioning error in 30% and 60% of lumbar full flexion and neutral position with eyes closed when standing was evaluated using an electrogoniometer.

RESULTS: The repositioning error was decreased in neutral, 30%, and 60% of lumbar flexion after the low-frequency and high-frequency WBV. Post hoc testing revealed that the effect of angle was not significant in repositioning error changes between high-frequency and low-frequency WBV (P > .05). However, the effect of low-frequency WBV on the repositioning error was significantly higher compared with high-frequency WBV (P < .05).

CONCLUSION: Low-frequency WBV might induce more improvement in the accuracy of lumbopelvic repositioning compared with high-frequency WBV with the method of WBV used in this study.

Author keywords: Proprioception, Spine, Low Back Pain

Author affiliations: NS, NM, AS, MP, AA: Department of Physiotherapy, School of Rehabilitation Sciences, Iran University of Medical Sciences and Health Services, Tehran, Iran; RB: Neuromuscular Rehabilitation Research Center, Semnan University of Medical Sciences, Semnan, Iran;