Conventional physical therapy following spinal cord injury (SCI) is an arduous task met with minimal returns
and quickly plateauing recovery. Unconventional therapies, such as robotic assisted gait training (RAGT) have
not produced the robust clinical gains that we all had hoped. Rodent RAGT is a nascent field, but it works on
the same principles as the clinical counterpart. We have previously quantified the loss of function and
spontaneous recovery of locomotion following SCI in rats. We have also investigated the ability of RAGT to
enhance this recovery. After studying over 100 rats we have learned that training in a resistive field is
detrimental, and training in a negative viscosity field is better than actively guiding the limbs through a healthy
stepping pattern. Unfortunately, none of these treatments are particularly good at restoring locomotion. We
believe that reanalysis of our existing data will uncover the optimal RAGT technique. Previously we grouped
animals based on the RAGT treatment they received. Upon further reflection, these groups are not based on
what the animals actually experienced, but how the robot was programmed. It may come to light that the actual
forces applied during training, a force profile, is what leads to greater recovery. With this proposal we plan to
uncover the optimal RAGT force profile by reanalyzing our existing data bi-directionally (does force profile
predict recovery?, does recovery predict force profile?). This will provide new insights into the importance of
the specific forces used in rehabilitation, and thus optimize RAGT. Aim 1 is to use cluster analysis to create
new treatment groups based on similar force profiles during training, and see if there is a difference in the level
of locomotor recovery. Aim 2 is to conduct outlier analysis to determine if rats that showed greater recovery of
locomotion had similar force profiles during training. By using two separate techniques we hope to uncover a
single (or very similar) force profile that optimizes RAGT. Training with such a force profile would represent a
major shift in current RAGT techniques, and lead to improvements in patients’ lives.
