Low back pain (LBP) is a major public health challenge all over the world [1, 2]. The lifetime prevalence of LBP is shown to be 84%, and the prevalence of chronic LBP is about 23%, 11 to 12% of people are disabled by LBP . Because of its high prevalence, LBP often leads to a large economic burden with regard to medical expenses and lost wages [4, 5]. In the United States, statistics show that total direct and indirect costs for the treatment of LBP are estimated to be more than $100 billion each year [6, 7].
Exercise therapy is recommended as an effective treatment for relieving pain and improving back function for patients with LBP by most clinical guidelines [3, 8–11]. During the past decade, whole body vibration (WBV) exercise has become increasingly popular for relieving musculoskeletal pain and improving health-related quality of life [12, 13]. In whole body vibration, the vibration signals are delivered through a vibratory platform or chair to expose a larger part of the body to the stimulation . WBV exercise consists of standing statically or performing dynamic movements on an oscillating platform. Exercise training using vibratory platforms may be a complementary training to standard physical rehabilitation programs. WBV provides amplitude of displacement (ranging from 0.7 to 14 mm) and a mechanical oscillation of a specific frequency (ranging from 0.5 to 80 Hz) [15, 16]. Several studies have demonstrated that whole body vibration exercise can reduce pain for women with fibromyalgia syndrome , young patients with musculoskeletal pain , and elderly patients with knee osteoarthritis .
At present, WBV exercise is being marketed as an intervention for patients with LBP [20–25]. There are two reasons WBV exercise may be useful for alleviating pain in patients with LBP. First, LBP is known to be associated with reduced abdominal and back extensor stabilization muscle activity . It has been proposed that WBV may assist in reducing LBP by activating stretch reflexes and subsequently activating and strengthening the abdominal and back extensor stabilization muscles . Second, LBP is known to be associated with paravertebral muscle spasm, and it has been suggested that WBV at frequencies below 20 Hz may reduce LBP by inducing muscle relaxation .
Whole body vibration exercise has a theoretical basis in treatment of LBP, as is evidenced by its clinical use. However, the efficacy of WBV exercise for low back pain is not without dispute. The results of several studies suggest that whole body vibration exercise relieves chronic back pain through a genuine analgesic effect [21–23]. On the other hand, some studies show that WBV exercise was not effective for patients with LBP [28, 29], and WBV has even been considered harmful .
It is important to ensure that the determination of the effectiveness of WBV exercise for LBP is based on scientific evidence so as not to waste staff time and resources and to avoid unnecessary stress for patients with LBP and their families. Thus, we conduct a single-blind randomized controlled trial (RCT) to determine the effects of WBV for patients with LBP compared to general exercise.