Asymmetric bone adaptations to soleus mechanical loading after spinal cord injury

This study investigates how electrical stimulation of the soleus muscle affects bone density in people with spinal cord injuries. The researchers examined changes in bone mineral density (BMD) in the tibia after several years of unilateral stimulation. They found that stimulating the soleus muscle led to increased bone density in the trained limb compared to the untrained limb. This effect was particularly noticeable in the central core and posterior half of the tibia. The findings suggest that carefully controlled mechanical loads, such as those from electrical stimulation, can protect bone in individuals with SCI. The specific direction of these loads may also play a significant role in how bone density adapts.

• 1
  After 4.5 to 6 years of training, the average trained limb BMD was 27.5% higher than the untrained limb BMD, indicating a significant bone-sparing effect.
• 2
  The training effect was more pronounced in the central core of the tibia cross-section, with a 40.5% difference in BMD between the trained and untrained limbs.
• 3
  A robust between-limb difference emerged in the posterior half of the tibia (76.1 mg/cm3 difference, p=0.0439), suggesting that the mechanical loads from soleus stimulation primarily affected this region.