According to Wolff's law, the bone will adapt to the stress under which it is placed. Bones perceive and respond to local dynamic loading, building form, and strength to support function (Wolff, 1892). In a healthy person, this “dynamic loading” is generated by muscle contractions through daily activities and specific training, but in the case of a frail or injured individual where typical exercise regimens are difficult, these mechanical signals can be translated in the form of vibration.
Effects of Vibration on Bone
When stress is applied to a part of the body, bone cells, osteocytes, activates osteoclasts, which remove damaged bone cells, and osteoblasts, which form new bones. Vibration therapy improves bone strength and density by increasing bone formation and decreasing bone resorption. A study conducted by the University of North Carolina, Department of Medicine revealed that stem cells in bone marrow can become bone-forming osteoblasts when exposed to low-intensity vibration.
Also, several studies demonstrate that vibration enhances bone and muscle circulation, increasing the supply of nutrients needed for repair. The alternating muscle contraction and relaxation produced by vibration also provide additional mechanical stress to the bone, adding to the loading effect, similar to other weight-bearing exercises.
Therapeutic Uses of Vibration on Bone Health
Osteoporosis and Osteopenia are bone disorders, characterized by low bone density, bone deterioration, and bone fragility. The difference between these two is in the matter of severity of bone density loss.Osteopenia is characterized by bone loss that is not as severe as osteoporosis.
In one study, low-magnitude high-frequency vibration has been proven to be “osteogenic,” meaning bone-forming, in osteoporotic bone and was able to promote fracture healing by enhancing callus formation, remodeling, and mineralization (Shi HF, et al., 2010).
Callus: Bony and cartilaginous material forming a connecting bridge across a bone fracture during repair— Encyclopaedia Britannica
Vibration therapy can provide noninvasive, anabolic mechanical signals to simulate exercise in bone and presents an attractive alternative to pharmacological treatments for osteoporosis (Thompson et. al., 2014). This, however, is transmitted via whole-body vibration treatment.
Particular attention in the therapeutic use of vibration on bone health is focused on fracture healing. This is where localized vibration therapy can be utilized to target specific fracture area to promote healing and fast recovery.
On Fracture Healing…
One of the complications of fracture healing is delayed union or non-union, resulting in prolonged recovery (Wood GW, 2007). The main goal of treatment is to shorten the bone healing period by different means, not only to provide shorter recovery but also to reduce the period of immobilization as this deprives the skeleton of mechanical loading.
The process of bone repair in fracture healing is similar in the normal skeleton (McKibbin B, 1978). Mechanical stimuli are required to promote and stimulate new bone formation (Yamaji et. al., 2001). Vibration therapy exerts its effects on bone tissue by the activation of muscles, which mechanically loads the bone (Fritton et. al., 2001). Also, vibratory signals become amplified within the bone tissue by stress-generated fluid flow, thereby activating bone-forming cells, which act as mechanosensor cells that respond to mechanical stimuli (Fritton et. al., 2001).
Localized vibration therapy can provide the mechanical stress that can mimic at least a percentage of the mechanical load that is subjected to a normal bone to create a bone rebuilding response, and fracture healing can be augmented by this process given that the frequency, amplitude, and duration of exposure are effective, safe, sufficient and within therapeutic range to stimulate a response.
Bone fractures, especially in the elderly, lead to severe functional disability. Low-intensity vibration application can be an adjunct to interventions and can provide effects to injured or even bed-bound patients to achieve successful fracture remodeling.
Simply put, stress is needed by our bones to maintain its integrity, and a vibration is a form of mechanical stress. Though not comparable to the amount of mechanical loading in a normal settings, vibrational stress from local vibration devices can deliver relevant mechanical signals at different levels of applicability and safety to patients who are otherwise unable to load their skeletons, like in osteoporotic, osteopenic and fractured individual. Localized vibration therapy can be an adjunct to physical and pharmacological treatments of people with skeletal disuse. Apart from its direct effect on the fracture site, it can also help provide pain relief and recovery to related structures around the injured area.
Recovapro massage guns are specifically designed to deliver localized vibration therapy on various health conditions and can help aid in fast recovery from bone injurysuch as Shin Splintsand Stress Fractures. Following cast removal and approval from the doctor, the following benefits are achieved with localized vibration therapy: