Low-Level, High-Frequency Mechanical Signals Enhance Musculoskeletal Development of Young Women With Low BMD

Abstract

The potential for brief periods of low-magnitude, high-frequency mechanical signals to enhance the musculoskeletal system was evaluated in young women with low BMD. Twelve months of this noninvasive signal, induced as whole body vibration for at least 2 minutes each day, increased bone and muscle mass in the axial skeleton and lower extremities compared with controls.Introduction: The incidence of osteoporosis, a disease that manifests in the elderly, may be reduced by increasing peak bone mass in the young. Preliminary data indicate that extremely low-level mechanical signals are anabolic to bone tissue, and their ability to enhance bone and muscle mass in young women was investigated in this study. Materials and Methods: A 12-month trial was conducted in 48 young women (15-20 years) with low BMD and a history of at least one skeletal fracture. One half of the subjects underwent brief (10 minutes requested), daily, low-level whole body vibration (30 Hz, 0.3g); the remaining women served as controls. Quantitative CT performed at baseline and at the end of study was used to establish changes in muscle and bone mass in the weight-bearing skeleton. Results: Using an intention-to-treat (ITT) analysis, cancellous bone in the lumbar vertebrae and cortical bone in the femoral midshaft of the experimental group increased by 2.1% (p ‫ס‬ 0.025) and 3.4% (p < 0.001), respectively, compared with 0.1% (p ‫ס‬ 0.74) and 1.1% (p ‫ס‬ 0.14), in controls. Increases in cancellous and cortical bone were 2.0% (p ‫ס‬ 0.06) and 2.3% (p ‫ס‬ 0.04) greater, respectively, in the experimental group compared with controls. Cross-sectional area of paraspinous musculature was 4.9% greater (p ‫ס‬ 0.002) in the experimental group versus controls. When a per protocol analysis was considered, gains in both muscle and bone were strongly correlated to a threshold in compliance, where the benefit of the mechanical intervention compared with controls was realized once subjects used the device for at least 2 minute/day (n ‫ס‬ 18), as reflected by a 3.9% increase in cancellous bone of the spine (p ‫ס‬ 0.007), 2.9% increase in cortical bone of the femur (p ‫ס‬ 0.009), and 7.2% increase in musculature of the spine (p ‫ס‬ 0.001) compared with controls and low compliers (n ‫ס‬ 30). Conclusions: Short bouts of extremely low-level mechanical signals, several orders of magnitude below that associated with vigorous exercise, increased bone and muscle mass in the weight-bearing skeleton of young adult females with low BMD. Should these musculoskeletal enhancements be preserved through adulthood, this intervention may prove to be a deterrent to osteoporosis in the elderly.

High-frequency loading positively impacts titanium implant osseointegration in impaired bone

“…This is in accordance with literature findings on the protective effect of ALN not only in implant osseointegration, but also in bone regeneration settings such as fracture healing [40]. The anabolic effects of HF loading on bone and bone healing have been reported in several animal [16][17][18]42] and clinical trials [19,20]. It is well established that bone has the potential of sensing and responding to very small mechanical signals when applied at HF [43].…”

“…The importance of using high-frequency (HF) mechanical loading, i.e., at a frequency beyond the physiological frequency (approx ∼3 Hz for mastication), is increasing because of the evidenced positive effect of HF loading on bone formation and fracture healing [16][17][18]. Furthermore, based on the clinical outcome of exercise studies [10,19,20], the advantages of using HF mechanical loading are considered to be safe and efficient. HF mechanical loading improves the bone's mechanical properties while being able to withstand the physiological demands [11].…”

“…HF mechanical loading improves the bone's mechanical properties while being able to withstand the physiological demands [11]. This makes HF mechanical loading a powerful non-pharmacological intervention not only for the treatment or prevention of osteoporosis but also for fracture healing and beyond [1,19,20]. Numerous in vivo systems employing HF loading have been successfully used, such as whole body vibration (WBV) devices [16][17][18] and individual limb compressive loading setups [21,22].…”

Extremely Small-magnitude Accelerations Enhance Bone Regeneration: A Preliminary Study

“…During the last decade, evidence for the anabolic and antiresorptive effects of high-frequency, low-level mechanical signals has accumulated [6,17,21]. These signals are most commonly applied through foot-based whole body vibrations [34] but retain their efficacy when applied as high-frequency oscillatory motions [15,31].…”

“…When these low-level mechanical signals are delivered at sufficiently high frequencies, such as by standing on a vertically oscillating plate (whole body vibration), they can stimulate bone cells to enhance bone formation, decrease resorption, and remodel into a stiffer and stronger structure with improved architectural characteristics [20,36,48]. Application of these extremely low-magnitude, highfrequency mechanical stimuli in recent human studies suggest beneficial effects in a healthy skeleton and in skeletons disturbed by local or systemic stimuli, including inactivity, hormonal changes, or low bone mass [17,35,46].…”