About this trial

This trial is enrolling individuals with chronic incomplete spinal cord injuries to test usage of daily acute intermittent hypoxia (dAIH), combined with two methods of hand training (massed practice, a high number of activity repetitions; or use of a hand exoskeleton). AIH is a procedure wherein the oxygen levels of breathed air are reduced for a short duration (<2 min), alternated by exposure to room air with normal oxygen levels. Previous studies have shown that AIH is a reasonably safe and promising technique. It has been shown to influence muscle activation, within 60-120 minutes of administration. This study examines the effects of dAIH in combination with two different methods of upper extremity training: 1) dAIH and massed practice training, which addresses gross upper extremity movements, grip and pinch strength, and coordination with the goal of 300 repetitions per training session. 2) dAIH therapy and training with a virtual reality hand exoskeleton rehabilitation device (Rapael Glove). Participants will be randomly assigned to one of five groups, including: • massed practice training with dAIH • massed practice training with sham dAIH • Rapael glove with dAIH • Rapael glove with sham dAIH • no training with dAIH Participants will not be informed about their oxygen levels; the sham treatment is normal air. The study will measure changes in strength, sensation, and functional tasks in the upper extremity/hand.