Muscle WeaknessNCT05956964
NM Balance Regulation With ULLS and Loss of Sleep
A study testing Sleep Restriction and Sleep Adequate in people with Muscle Weakness and Quadriceps Muscle Atrophy, run by Lance Bollinger at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Muscle Weakness, Quadriceps Muscle Atrophy, Sleep Disturbance
- What is being tested?
- Sleep Restriction and Sleep Adequate
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteUnited States
- Study dates
- 10 Aug 2023to 14 Mar 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age between 18 and 50 years
- Regularly engaging in aerobic exercise (> 150min/wk) and resistance exercise (>1 time per week) for the past 12 months
- Regularly sleep at least 7 hours per night
Who cannot join
- Age < 18 or > 50 years
- Height between <150 (F) or <170 (M) and > 190 cm (both sexes)
- Waist circumference < 55cm or > 90cm (F) and < 75cm or > 100cm (M)
- Body mass index < 18.5 or > 27.5
- Do not regularly sleep between 7 and 9 hours each night
- Have a known sleep disorder
Show all 19Show fewer
- Not regularly engaging in exercise for previous 12 months
- Blood clotting disorder
- Heart arrhythmia
- Implanted device which could negatively be affected by electrical impulse or strong magnetic field such as pacemaker, internal defibrillator, or cochlear implant
- Diagnosed cardiovascular, pulmonary, renal, or metabolic disease
- Pregnancy (within previous 6 months)
- Oral contraceptive use (within previous three months)
- High resting blood pressure (>140 systolic and/or > 90 diastolic)
- Currently or previously undergone gender-affirming therapy (hormone therapy or sexual reassignment surgery)
- Low back or leg injury in previous 6 months
- Currently taking medication to assist with sleep
- Muscle, bone, or joint injury that limits physical activity within previous 6 months
- Neurological disorder which affects balance (such as multiple sclerosis or Parkinson's disease)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of Unloading and Sleep Restriction on Balance Regulation and Quadriceps Structure and Contractile Function
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.
Read the 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.
- Being tested
- Sleep Restriction, Sleep Adequate
- Keywords
- sleep restriction, spaceflight, unweighting, posture
- Medical subject headings
- Muscle Weakness, Parasomnias
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sleep RestrictionBehavioural
5 hours of sleep for 3 days
Sleep AdequateBehavioural
9 hours of sleep for 3 days
| Study group | Role | What they receive |
|---|---|---|
| Sleep Restriction (SR) | Experimental | The research team will provide participants with a pair of shoes to wear throughout the study. The right shoe will be modified to include a 5cm (approximately 2") rocker-style platform which will keep the left leg suspended during walking. Participants will also be provided with a pair of short crutches to assist with walking. Participants in the SR group will sleep only 5 hours for three consecutive nights. Receives: Behavioral: Sleep Restriction |
| Sleep Adequate (SA) | Active comparator | The research team will provide participants with a pair of shoes to wear throughout the study. The right shoe will be modified to include a 5cm (approximately 2") rocker-style platform which will keep the left leg suspended during walking. Participants will also be provided with a pair of short crutches to assist with walking. Participants in the SA group will sleep for 9 hours for three consecutive nights. Receives: Behavioral: Sleep Adequate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Percentage in Interpolated Twitch Torque of the Loaded and Unloaded Leg
Subjects will sit upright in an isokinetic dynamometer with the knee at 60° flexion. Gel electrode pads will be placed over the femoral nerve and just proximal to the patellar tendon. Square wave, constant current, doublet pulses from an electrical stimulator will be used to evoke twitches prior to, during, and following a maximal voluntary isometric contraction (MVIC). Twitch torque will be measured in Newton-meters (Nm). Outcome data are reported as the percentage change in voluntary activation from baseline.
Measured: Baseline and study completion, approximately 14 days
Percent Change in Single Leg Stand (SLS)
Balance will be assessed using a dual force plate system. Participants will be asked to stand on one leg and maintain their balance for 15 seconds. Specific outcome measures include percentage change in center of pressure 95% ellipse area (sq. mm) compared to baseline.
Measured: Baseline and study completion, approximately 14 days
Muscle Volume
Diffusion Tensor Imaging (DTI) will be used to quantify muscle volume of the loaded and unloaded leg. Subjects will lay supine, and slightly flex the knee (~10°) to elongate and straighten the quadriceps. A spine array coil will be placed on the MR-scanner table and a flexible body coil wrapped around the upper thigh and centered over mid-thigh of the dominant leg. Multiple images will be taken. DSI Studio program will be used to analyze raw images.
Measured: Post-intervention, approximately 14 days after start of study
Percent Change in Center of Pressure Velocity During Single Leg Stance
Balance will be assessed using a dual force plate system. Participants will stand on one leg on a stable force deck for 15 seconds. The mean Center of Pressure (CoP) velocity will be measured in millimeters per second (mm/s) for loaded and unloaded limbs. Outcomes are reported as the percentage change in mean velocity compared to pre-intervention.
Measured: Baseline and study completion, approximately 14 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2023
- Study start10 Aug 2023
- Primary completion14 Mar 2025
- Study completion14 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Muscle WeaknessStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Subjects will be randomized to different arms via a matched-pairs design using the following criteria: age, sex, and race. Within each arm, the loaded limb will serve as an internal control to assess effects of unloading.
- Masking
- None (open label)
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- Lance Bollinger
- Sponsor type
- University, hospital or other
- Collaborators
- National Aeronautics and Space Administration (NASA)
- Responsible party
- Sponsor-investigator, Lance Bollinger, University of Kentucky
- Investigators
- Lance Bollinger, PhD, Principal investigator, University of Kentucky
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05956964
- Sponsor's protocol ID
- 84290
- Other IDs
- 80NSSC20M004
- Status last verified
- May 2026
- First submitted
- 3 Jul 2023
- Last updated
- 17 Jun 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Unloading and Sleep Restriction on Balance Regulation and Quadriceps Structure and Contractile Function
- ClinicalTrials.gov ID
- NCT05956964
- Acronym / sponsor ID
- 84290
- Keywords
- sleep restriction, spaceflight, unweighting, posture
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- Lance BollingerUniversity, hospital or other
- Collaborators
- National Aeronautics and Space Administration (NASA)
- Study start
- 10 Aug 2023 (actual)
- Primary completion
- 14 Mar 2025 (actual)
- Study completion
- 14 Mar 2025 (actual)
- First posted
- 24 Jul 2023 (actual)
- Results
- Posted 17 Jun 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Subjects will be randomized to different arms via a matched-pairs design using the following criteria: age, sex, and race. Within each arm, the loaded limb will serve as an internal control to assess effects of unloading.
| Arm | Type | Receives |
|---|---|---|
| Sleep Restriction (SR) | Experimental | Behavioral: Sleep RestrictionThe research team will provide participants with a pair of shoes to wear throughout the study. The right shoe will be modified to include a 5cm (approximately 2") rocker-style platform which will keep the left leg suspended during walking. Participants will also be provided with a pair of short crutches to assist with walking. Participants in the SR group will sleep only 5 hours for three consecutive nights. |
| Sleep Adequate (SA) | Active comparator | Behavioral: Sleep AdequateThe research team will provide participants with a pair of shoes to wear throughout the study. The right shoe will be modified to include a 5cm (approximately 2") rocker-style platform which will keep the left leg suspended during walking. Participants will also be provided with a pair of short crutches to assist with walking. Participants in the SA group will sleep for 9 hours for three consecutive nights. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Age between 18 and 50 years
- Regularly engaging in aerobic exercise (> 150min/wk) and resistance exercise (>1 time per week) for the past 12 months
- Regularly sleep at least 7 hours per night
Key exclusion criteria (19 listed)
- Age < 18 or > 50 years
- Height between <150 (F) or <170 (M) and > 190 cm (both sexes)
- Waist circumference < 55cm or > 90cm (F) and < 75cm or > 100cm (M)
- Body mass index < 18.5 or > 27.5
- Do not regularly sleep between 7 and 9 hours each night
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Sleep Restriction5 hours of sleep for 3 days | Behavioural | Sleep Restriction (SR) |
| Sleep Adequate9 hours of sleep for 3 days | Behavioural | Sleep Adequate (SA) |
Primary outcome
Change in Percentage in Interpolated Twitch Torque of the Loaded and Unloaded Leg
Time frame: Baseline and study completion, approximately 14 days
Subjects will sit upright in an isokinetic dynamometer with the knee at 60° flexion. Gel electrode pads will be placed over the femoral nerve and just proximal to the patellar tendon. Square wave, constant current, doublet pulses from an electrical stimulator will be used to evoke twitches prior to, during, and following a maximal voluntary isometric contraction (MVIC). Twitch torque will be measured in Newton-meters (Nm). Outcome data are reported as the percentage change in voluntary activation from baseline.
Percent Change in Single Leg Stand (SLS)
Time frame: Baseline and study completion, approximately 14 days
Balance will be assessed using a dual force plate system. Participants will be asked to stand on one leg and maintain their balance for 15 seconds. Specific outcome measures include percentage change in center of pressure 95% ellipse area (sq. mm) compared to baseline.
Muscle Volume
Time frame: Post-intervention, approximately 14 days after start of study
Diffusion Tensor Imaging (DTI) will be used to quantify muscle volume of the loaded and unloaded leg. Subjects will lay supine, and slightly flex the knee (~10°) to elongate and straighten the quadriceps. A spine array coil will be placed on the MR-scanner table and a flexible body coil wrapped around the upper thigh and centered over mid-thigh of the dominant leg. Multiple images will be taken. DSI Studio program will be used to analyze raw images.
Percent Change in Center of Pressure Velocity During Single Leg Stance
Time frame: Baseline and study completion, approximately 14 days
Balance will be assessed using a dual force plate system. Participants will stand on one leg on a stable force deck for 15 seconds. The mean Center of Pressure (CoP) velocity will be measured in millimeters per second (mm/s) for loaded and unloaded limbs. Outcomes are reported as the percentage change in mean velocity compared to pre-intervention.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Jun 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lance Bollinger, PhD principal investigator
University of Kentucky
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Sleep Restriction and Sleep Adequate in people with Muscle Weakness and Quadriceps Muscle Atrophy, run by Lance Bollinger at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 17 Jun 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Percentage in Interpolated Twitch Torque of the Loaded and Unloaded Leg (time frame: Baseline and study completion, approximately 14 days). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Jun 2026.