Research by University of Iowa professor, Richard Shields, Ph.D. can provide a ray of hope for a cure for patients with spinal cord injury (SCI).
Virtually every SCT patient foresees a bleak future with severe osteoporosis and muscle atrophy continually haunting him or her. Loss of bone mineral density up to the extent of 30 percent has often been demonstrated making the paralyzed limbs of such patients especially vulnerable to fracture.
In addition, excess calcium leached from the bones into the blood can lead to secondary problems such as multiple fractures leading to amputation, and kidney problems caused by which further deteriorates the health of these SCI patients. Therefore maintaining the bone integrity has important implications for improving the health of SCI patients.
Electrical stimulation has been shown to increase muscle contraction while exerting mechanical loading greater than body weight on the targeted bone. This method of therapeutic stress keeps the skeletal system healthy, thereby improving the patient's health quality while preventing secondary complications at the same time. The team from the University of Iowa used a computer-controlled device that delivered defined, measurable doses of load, approxmately1.5 times the body weight to the tibia of one leg of each participant. Normal exercise principles were followed, training the targeted muscle and bone close to20 to 30 minutes each day, five days a week.
Towards the end of the three-year studies it was found that BMD for the stimulated limbs was about 32 percent greater than the unstimulated limb, on an average. In addition, the cross-sectional area of trained muscles was about 30 percent larger than those of the untrained muscles. Trained muscles could also generate about 50 percent more force than the untrained muscles.
The results of the study are published in the January 11 issue of the Journal of Neurophysiology and the March 1 issue of Spine.
These studies are unique because of the early intervention with mechanical loading after SCI that is within six months of their injury. Also, the studies were conducted over a period of three years, which mostly covers the period of rapid BMD loss in SCI patients. In addition, the experiment was quite focused, with only one muscle and bone examined and only for one leg of each participant, thereby making the effects clearly observable.
The findings are useful to preserve the musculoskeletal system after SCI. Future studies must consider efficient methods to deliver such therapeutic stresses to the entire lower extremity.
They may also be useful for astronauts who experience bone loss and muscle wasting due to long periods spent in low gravity.