Effect of weight-bearing activities on bone mineral density in spinal cord injured patients during the period of the first two years

Study design: Prospective study on patients with spinal cord injuries. Objectives: To evaluate the loss of bone mineral density (BMD) in various body regions of patients with spinal cord injury (SCI) and its dependence on weight bearing activities during 2 years post injury. Methods: BMD of the whole body was measured in patients with SCI. Baseline measurement was performed in 6-16 weeks after SCI, the second and the third-respectively 12 and 24 months after injury. Fifty-four subjects were selected and divided into two groups: standing and non-standing. From these groups 27 pairs were made according to gender, age and height. Results: There was found to be a well-marked decrease in BMD values for lower extremities, but there was no significant difference between paraplegic and tetraplegic patients 1 and 2 year after injury. Leg BMD reduced by 19.62% (95% CI, 17-22%) in the standing group and by 24% (95% CI, 21-27%) in non-standing group during the first year. Two years after SCI patients in standing group had significantly higher leg BMD-1.018 g/cm(2) (95% CI, 0.971-1.055 g/cm(2)) than in the non-standing group-0.91 g/cm(2) (95% CI, 0.872-0.958 g/cm(2)) (P <= 0.0001). Conclusion: SCI patients who performed daily standing >= 1 h and not less than 5 days per week, had significantly higher BMD in the lower extremities after 2 years in comparison to those patients who did not perform standing.