NCT05956964

NM Balance Regulation With ULLS and Loss of Sleep

Effects of Unloading and Sleep Restriction on Balance Regulation and Quadriceps Structure and Contractile Function

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 16 (actual)
• Sponsor: Lance Bollinger · Academic / Other
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

Summary

The goal of this trial is to learn about how restricted sleep and not bearing weight on the leg affects muscle strength and posture control. Participants will walk exclusively on one leg, sleep at differing intervals, and complete posture tests, muscle strength tests, and muscle imaging. Researchers will compare adequate sleep and restricted sleep to see if muscle strength and posture are affected.

Detailed description

During space flight, astronauts experience multiple physiological stimuli (such as microgravity and altered sleep cycles) which independently impair balance and strength. The goal of this project is to determine how these stimuli interact to affect static single-leg balance, balance during dynamic tasks, and muscle recruitment, strength, and remodeling. Subjects (healthy adults age 18-50) will complete 13 days of unilateral lower limb suspension (ULLS, the gold standard analog for measuring space flight in ambulatory subjects). For the final three days of the study, subjects will be randomly assigned (via a matched pairs approach) to either normal sleep (7-9 hours per night) or restricted sleep (5 hours per night). Before and after the study, subjects will complete balance assessments and measures of muscle strength and recruitment. At the end of the study, subjects will also undergo diffusion tensor imaging for the thighs. Balance testing will be conducted by examining sway in center of gravity during single leg stance and when stepping down from a box. Muscle strength and recruitment will be assessed via submaximal and maximal voluntary isometric contractions. Additionally, an interpolated twitch experiment will be performed to assess muscle recruitment and twitch properties. Diffusion Tensor imaging will be used to quantify muscle size and structure. As prophylactic treatment against deep vein thrombosis (the major risk of ULLS), subjects will take an aspirin (81mg daily), wear compression stockings, complete passive range of motion exercises, and use intermittent pneumatic compression devices during sedentary times.

Conditions

• Muscle Weakness
• Quadriceps Muscle Atrophy
• Sleep Disturbance

Interventions

Type	Name	Description
BEHAVIORAL	Sleep Restriction	5 hours of sleep for 3 days
BEHAVIORAL	Sleep Adequate	9 hours of sleep for 3 days

Timeline

• Start date: 2023-08-10
• Primary completion: 2025-03-14
• Completion: 2025-03-14
• First posted: 2023-07-24
• Last updated: 2025-04-01

Locations

1 site across 1 country: United States