RCT of Vibration Effect on Vertebral BMD in Disabled Patients

Osteoporosis is an age-related disease with progressive loss of bone, leading to fragile bone. It is one of the major health issues in elderly and causes medical, social and economic impacts globally. Patients with osteoporosis have high risk of osteoporotic fractures. Low-magnitude high-frequency vibration (LMHFV) is a non-invasive biophysical intervention providing whole-body mechanical stimulation. Previous studies showed that LMHFV is beneficial to muscle strength(1), postural control(2), balancing ability(3, 4), new bone formation(5-7), spinal bone mineral density (BMD)(8), and blood circulation(9). During the LMHFV treatment, elderly needs to stand upright on the platform for 20min/day. However, some elderlies with poor standing ability cannot stand for a long period. Therefore, the design of vibration platform is modified for the disabled patients and the efficacy of LMHFV on this group of elderlies will be verified. It is hypothesized that new design of LMHFV is beneficial to wheelchair users in terms of vertebral bone mineral density, muscle health and musculoskeletal functions.

This study is a single-blinded randomized controlled trial to investigate the effect of LMHFV on vertebral BMD, muscle health, balancing ability and functional ability in wheelchair users (mainly on wheelchair for outdoor activities). Healthy elderlies aged 65 years or above, with walking difficulties and using wheelchair are eligible. We exclude anyone who: \[1\] cannot stand and walk independently, \[2\] have vibration treatment before, \[3\] with malignancy, \[4\] with acute fractures or severe osteoarthritis (18), \[5\] with cardiovascular concern such as with pace-maker in-situ, \[6\] with chronic inflammatory conditions known to affect muscle metabolism such as rheumatoid arthritis, and \[7\] with high frequency of physical activities, such as subjects who participated in regular exercise five times a week or more. Recruited subjects will be randomized to either LMHFV or control group. Subject assigned to LMHFV group will receive LMHFV (35Hz, 0.3g, 20min/day, at least 3 times/week) for 6 months. The primary outcome is BMD at the lumbar spine to be assessed by dual-energy X-ray absorptiometry (DXA) that is clinically recommended for the diagnosis of osteoporosis. All primary and secondary outcome assessments for all groups will be performed in the investigators' institute at baseline and 6 months post-treatment.