A Wearable Garment To Mitigate Low Back Pain In Astronauts: 2818 Board #279 May 29 10:30 AM - 12:00 PM

The microgravity environment can have detrimental impacts on human health. Muscle atrophy, declines in bone mass, wedging of vertebral bodies, loss of normal spinal curvature, and decreased functional capacity are all consequences of prolonged microgravity exposure. Atrophy of the muscles along, and around, the spine is one of the primary contributors to the development of low back pain in space. PURPOSE: To design and fabricate a low-cost, diurnally worn upper-body garment with integrated neuromuscular electrical stimulation to prevent and mitigate low back pain in astronauts. METHODS: A custom fitted, upper-body garment that contained a neuromuscular electrical stimulation system was originally designed in modeling software (Solidworks Premium 2018, Waltham, MA). The garment was fabricated using highly durable, anti-microbial material (88.7% polyester, 8.6% lycra, 2.7% silver ion fiber). An elastic belt for additional compression to maximize contact between skin and electrodes was also incorporated. Four hydrogel electrodes were placed over motor points of the erector spinae and multifidus musculature. The wireless electrodes sent signals to a controller, all of which were integrated into the garment. A frequency of 50 Hz, pulse width of 200 μs, amplitude of 14 to 21 mA, and an on/off time of 20 sec was used during testing. Four participants with low back pain wore the garment and recorded pain levels, via a visual analog scale, at strategic times before and after the performance of the following exercises in our laboratory: isometric base, I’s, T’s, and Y’s, shoulder adduction and flexion, hamstring curls, inverted rows, pull-ups, and seated wood choppers. A Friedman’s ANOVA was used to test for differences in subjective pain measures with a significance of 0.05. RESULTS: No differences in pain were found at baseline (4.5 ± 0.6) when compared to pain following an exercise bout immediately after baseline (5.0 ± 0.8), after 8 hours of continuous wear (3.3 ± 1.5), and immediately following the exercise bout after this 8-hour timepoint (3.3 ± 1.5; p = 0.112). CONCLUSION: Further testing is needed to determine if the integration of neuromuscular electrical stimulation into a diurnally worn upper-body garment may mitigate atrophy of the erector spinae and multifidus muscles, resulting in decreased low back pain.