The purpose of this research study is to determine the effect of mechanical vibrations on bones of persons with spinal cord injury.

One of the major complications in persons with spinal cord injury (SCI) is marked bone loss because it greatly predisposes to skeletal fractures, even after minimal trauma. The use of low magnitude mechanical stimulation has been shown to be both safe and effective in improving bone mass and strength in animal studies. This modality has also been shown a beneficial effect in children with disability and in postmenopausal women. The investigators are interested in obtaining data to determine the possible benefits that mechanical intervention with vibratory stimulation may have on bone in individuals with subacute SCI (e.g., >1 month after injury but <1 year). Changes in bone density and mass of the leg and arm will be determined by dual energy X-ray absorptiometry (DXA); bone architecture of the distal leg and distal arm will be determined by peripheral quantitative computed tomography; circulating metabolic markers of bone will also be performed.

OBJECTIVES

In persons with subacute spinal cord injury:

1. To determine differences in bone mineral mass and parameters of bone structural integrity of the stimulated tibia versus the unstimulated tibia.
2. To determine changes in the metabolic markers of bone resorption and formation in persons with subacute spinal cord injury.

Inclusion Criteria:

1. Males;
2. Age 18-65;
3. Non-ambulatory SCI, with ASIA level A or B (ASIA A or B at the time of enrollment);
4. Neurological level of injury C3-T10;
5. Duration of injury >1 month after injury but <1 year; and 6.25(OH)D levels 30ng/ml (patients with values <30ng/ml will be supplemented with vitamin D to normalize values prior to study participation).

Exclusion Criteria:

1. Osteoporosis or low bone mass as determined by medical history or DXA at the baseline visit;
2. Pressure ulcer that may be exacerbated by the experimental procedure;
3. Fracture of the lower extremity within the past 5 years;
4. Active heterotopic ossification (HO);
5. History of metabolic bone disease;
6. Knee replacement(s);
7. Metal hardware in the lower extremities;
8. Bisphosphonate administration;
9. Severe underlying chronic illness (cardiac, pulmonary, gastrointestinal, etc.);
10. Renal disease (creatinine clearance < 40 mL/min);
11. 25(OH)D levels <30ng/ml;
12. Endocrine disorders known to be associated with osteoporosis (hyperthyroidism, hypercortisolism, and/or hypogonadism);
13. Alcoholism;
14. Seizure disorders;
15. History of kidney stones; and
16. Compliance 85% for every month up to the 4-month time-point

1.5 years

Subject recruitment was untenable due to the physiological and psychological healing necessary during the sub-acute phase of spinal cord injury.