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Project Title:  A Low Intensity Mechanical Countermeasure to Prohibit Osteoporosis in Astronauts During Long-Term Spaceflight Reduce
Fiscal Year: FY 2007 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 03/15/2004  
End Date: 03/15/2007  
Task Last Updated: 06/05/2008 
Download report in PDF pdf
Principal Investigator/Affiliation:   Rubin, Clinton  Ph.D. / State University of New York 
Address:  Department of Biomedical Engineering 
Center for Biotechnology 
Stony Brook , NY 11794-2580 
Email: clinton.rubin@sunysb.edu 
Phone: 631-632-8521  
Congressional District:
Web: http://www.bme.sunysb.edu  
Organization Type: UNIVERSITY 
Organization Name: State University of New York 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Judex, Stefan  State University of New York at Stony Brook 
Qin, Yi-Xian  State University of New York at Stony Brook 
Key Personnel Changes / Previous PI: 0
Project Information: Grant/Contract No. NNJ04HD87A 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: ILSRA 2001 
Grant/Contract No.: NNJ04HD87A 
Project Type: FLIGHT 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Osteo:Risk Of Early Onset Osteoporosis Due To Spaceflight (No longer used, July 2020)
Human Research Program Gaps: (1) B01:a) Is there an increased lifetime risk of fragility fractures/osteoporosis in astronauts (Merged with Osteo 2); b) is bone strength completely recovered post-flight (merged with Osteo 3) and does BMD reflect it (Closed); c) what are the risk factors for poor recovery of BMD/bone strength? (Merged with Osteo 4) (IRP Rev D)
Flight Assignment/Project Notes: In flight development phase (not yet manifested)

NOTE: end date changed to 3/15/07 per info from PI (6/08)

Task Description: Osteoporosis, the progressive loss of bone density and strength that cripples tens of millions on our planet, distinguishes itself as perhaps the greatest physiologic obstacle to an extended human presence in space. The principal objectives of this proposal are to establish the efficacy of a unique, mechanical countermeasure to inhibit bone loss - and muscle strength- in the lower appendicular skeleton of astronauts and payload specialists during International Space Station missions. Using a ground based model of microgravity, the tail-suspended rat, we have shown that brief exposure (10 minutes) to extremely low magnitude (0.25g, engendering <5 microstrain), high frequency (30-90 Hz) mechanical signals will inhibit the bone loss which typically parallels disuse, even though 10 minutes of full weightbearing failed to curb this loss. Longer-term experiments in sheep have shown this stimulus to be strongly anabolic, increasing bone mineral density, trabecular number and connectivity, and improving bone strength. Preliminary results in post-menopausal women and children with cerebral palsy indicate that this intervention can inhibit, and perhaps reverse, osteoporosis. To determine this intervention's ability to inhibit bone loss - and muscle strength - in people during prolonged space missions, we will subject astronauts, in single let stance, to brief exposures to the low level stimulus (10 minutes at 30 Hz, 0.3g), allowing the contralateral limb to serve as an intra-subject control. The proposal is structured to "piggy-back" onto ongoing flight studies, and thus the assays for efficacy will be determined by collaborative decisions between NASA teams studying the musculoskeletal system. At a minimum, DXA, QCT, and muscle strength measurements will be made both pre- and post- flight. This work represents a critical step in establishing a physiologically based, non-pharmacologic, non-invasive treatment for osteoporosis, for use on Earth or in space.

Research Impact/Earth Benefits: The intervention represents the basis for a non-pharmacologic interevention for the prevention and/or reversal of bone loss (osteoporosis) here on earth. Three clinical studies have been completed (post-menopausal women, children with cerebral palsy, young women w/ osteoporosis), each which supports the hypothesis that low-level mechanical signals can benefit the mass and morphology of the musculoskeletal system.

Task Progress & Bibliography Information FY2007 
Task Progress: Project ended sometime in early 2007.

Bibliography Type: Description: (Last Updated: 10/22/2009) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Muir, J., Evans, H., Judex, S., Qin, Y-X., Lang, T, Rubin, CT. "Extended Bed-Rest, Like Spaceflight, Causes Rapid and Significant Loss of Bone Mineral Density and Postural Control." 28th Annual Meeting of the American Society for Bone and Mineral Research, Philadelphia, Pennsylvania, September 15-19, 2006.

Abstracts of the 28th Annual Meeting of the American Society for Bone and Mineral Research, September 2006. , Sep-2006

Abstracts for Journals and Proceedings Qin, Y-X., Xia, Y, Lin, W., Evans, H., Judex, S., & Rubin, C. "Bone Quality and Quantity Assessment in 90-Day Bed Rest Using Confocal Scanning Ultrasound System and DEXA Measurement." 28th Annual Meeting of the American Society for Bone and Mineral Research, Philadelphia, Pennsylvania, September 15-19, 2006.

Abstracts of the 28th Annual Meeting of the American Society for Bone and Mineral Research, Sept 2006. , Sep-2006

Abstracts for Journals and Proceedings Muir J, Judex S, Qin Y, Rubin CT. "Safety of Whole Body Vibration, Considered for the Prevention and/or Treatment of Osteoporosis, Relative to Standards Set by the International Safety Organization." 28th Annual Meeting of the American Society for Bone and Mineral Research, Philadelphia, Pennsylvania, September 15-19, 2006.

Abstracts of the 28th Annual Meeting of the American Society for Bone and Mineral Research, Sept 2006. , Sep-2006

Abstracts for Journals and Proceedings Rubin CT. "Mechanical Signals as the Basis for a Non-Pharmacologic Treatment for Osteoporosis." Translational Research Symposium for the 28th Annual Meeting of the American Society for Bone and Mineral Research, Philadelphia, Pennsylvania, September 15-19, 2006.

Abstracts, Translational Research Symposium for the 28th Annual Meeting of the American Society for Bone and Mineral Research, Sept 2006. , Sep-2006

Abstracts for Journals and Proceedings Rubin C. "Harnessing mechanobiology: anabolic potential of low-level mechanical signals as a therapy for osteoporosis." 12th Annual Canadian Connective Tissue Conference, University of Ottawa, Ottawa, Canada, May 25-26, 2006.

Abstracts, 12th Annual Canadian Connective Tissue Conference, May 2006, p. 36. , May-2006

Abstracts for Journals and Proceedings Holguin N, Muir J, Evans H, Qin Y-X, Rubin C, Wagshul M, Judex S. "Volume changes of intervertebral disc, muscle and adipose tissue under long term bedrest." 2006 Annual Fall Meeting of the Biomedical Engineering Society, Chicago, Illinois, October 11-14, 2006.

Proceedings, 2006 Annual Fall Meeting of the Biomedical Engineering Society, Chicago, Illinois, October , 2006. , Oct-2006

Abstracts for Journals and Proceedings Patel M, Tlish R, Rubin C, Jo H. "Low-magnitude, high frequency mechanical vibration prevents simulated microgravity-induced decrease in a bone formation response in osteoblasts. " 57th International Astronautical Congress, Valencia, Spain, October 2-6, 2006.

Transactions, 57th International Astronautical Congress, October 2006. , Oct-2006

Articles in Peer-reviewed Journals Rubin C, Judex S, Qin YX. "Low-level mechanical signals and their potential as a non-pharmacological intervention for osteoporosis." Age Ageing. 2006 Sep;35 Suppl 2:ii32-ii36. PMID: 16926201 , Sep-2006
Books/Book Chapters Rubin C, Rubin J. "Biomechanics and mechanobiology of bone." in "Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, Sixth Edition." Ed. M. Fauvus. Washington, D.C. : American Society of Bone & Mineral Research, c2006. pp. 36-42., Jun-2006
Books/Book Chapters Qin Y-X, Lin W, Mittra E, Xia Y, Rubin C, Mueller R. "Non-invasive Bone Quality Assessment Using Quantitative Ultrasound Imaging and Acoustic Parameters." in "Advanced Bioimaging Technologies in Assessment of the Quality of Bone and Scaffold Materials." Ed. L. Qin et al. Springer, in press. Due to be published May 2007., May-2007
Project Title:  A Low Intensity Mechanical Countermeasure to Prohibit Osteoporosis in Astronauts During Long-Term Spaceflight Reduce
Fiscal Year: FY 2006 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 03/15/2004  
End Date: 03/15/2007  
Task Last Updated: 12/14/2006 
Download report in PDF pdf
Principal Investigator/Affiliation:   Rubin, Clinton  Ph.D. / State University of New York 
Address:  Department of Biomedical Engineering 
Center for Biotechnology 
Stony Brook , NY 11794-2580 
Email: clinton.rubin@sunysb.edu 
Phone: 631-632-8521  
Congressional District:
Web: http://www.bme.sunysb.edu  
Organization Type: UNIVERSITY 
Organization Name: State University of New York 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Judex, Stefan  State University of New York at Stony Brook 
Qin, Yi-Xian  State University of New York at Stony Brook 
Key Personnel Changes / Previous PI: 0
Project Information: Grant/Contract No. NNJ04HD87A 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: ILSRA 2001 
Grant/Contract No.: NNJ04HD87A 
Project Type: FLIGHT 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Osteo:Risk Of Early Onset Osteoporosis Due To Spaceflight (No longer used, July 2020)
Human Research Program Gaps: (1) B01:a) Is there an increased lifetime risk of fragility fractures/osteoporosis in astronauts (Merged with Osteo 2); b) is bone strength completely recovered post-flight (merged with Osteo 3) and does BMD reflect it (Closed); c) what are the risk factors for poor recovery of BMD/bone strength? (Merged with Osteo 4) (IRP Rev D)
Flight Assignment/Project Notes: In flight development phase (not yet manifested)

NOTE: End date changed to 3/15/2007 (from 3/15/2009) for database validation reasons (6/2008)

Task Description: Osteoporosis, the progressive loss of bone density and strength that cripples tens of millions on our planet, distinguishes itself as perhaps the greatest physiologic obstacle to an extended human presence in space. The principal objectives of this proposal are to establish the efficacy of a unique, mechanical countermeasure to inhibit bone loss - and muscle strength- in the lower appendicular skeleton of astronauts and payload specialists during International Space Station missions. Using a ground based model of microgravity, the tail-suspended rat, we have shown that brief exposure (10 minutes) to extremely low magnitude (0.25g, engendering <5 microstrain), high frequency (30-90 Hz) mechanical signals will inhibit the bone loss which typically parallels disuse, even though 10 minutes of full weightbearing failed to curb this loss. Longer-term experiments in sheep have shown this stimulus to be strongly anabolic, increasing bone mineral density, trabecular number and connectivity, and improving bone strength. Preliminary results in post-menopausal women and children with cerebral palsy indicate that this intervention can inhibit, and perhaps reverse, osteoporosis. To determine this intervention's ability to inhibit bone loss - and muscle strength - in people during prolonged space missions, we will subject astronauts, in single let stance, to brief exposures to the low level stimulus (10 minutes at 30 Hz, 0.3g), allowing the contralateral limb to serve as an intra-subject control. The proposal is structured to "piggy-back" onto ongoing flight studies, and thus the assays for efficacy will be determined by collaborative decisions between NASA teams studying the musculoskeletal system. At a minimum, DXA, QCT, and muscle strength measurements will be made both pre- and post- flight. This work represents a critical step in establishing a physiologically based, non-pharmacologic, non-invasive treatment for osteoporosis, for use on Earth or in space.

Research Impact/Earth Benefits: The intervention represents the basis for a non-pharmacologic interevention for the prevention and/or reversal of bone loss (osteoporosis) here on earth. Three clinical studies have been completed (post-menopausal women, children with cerebral palsy, young women w/ osteoporosis), each which supports the hypothesis that low-level mechanical signals can benefit the mass and morphology of the musculoskeletal system.

Task Progress & Bibliography Information FY2006 
Task Progress: The osteoporosis which develops in microgravity is one of the greatest hurdles to an extended human presence in space. Earth-based animal and human studies have demonstrated that extremely low magnitude mechanical loading, if imposed at a high frequency, is strongly anabolic to the skeleton, and can serve to inhibit the bone loss, which typically parallels disuse. This experiment is designed to evaluate the efficacy of this unique biomechanical countermeasure to inhibit the microgravity induced osteoporosis. To achieve this in a non-invasive, non-pharmacologic means would have tremendous impact not only in space, but would also address the bone loss which plagues over 20 million people world wide each year on earth.

During extended missions ISS crewmembers will receive ten-minute daily doses of high frequency (30Hz), low magnitude (0.3g, or 3m•s-2) mechanical accelerations. The subject will be secured to an oscillating plate by a shoulder harness, at 60% of their pre-launch body mass thus imparting sufficient force to allow the vibration of the platform to induce 0.3g accelerations to the lower appendicular and axial skeleton. The experimental equipment is designed such that it will not transmit vibration to the vehicular structure.

Following flight durations of at least three months, the bone quantity and quality will be evaluated by comparing post-flight DEXA, QCT and ultrasound measurements to baseline (pre-flight measurements). The principal areas of interest will be R&L femora, tibia, calcaneus, the spine (L1-4), and non-dominant radius. Assays will evaluate bone density, trabecular and cortical bone density, cortical thickness, apparent bone quality, and bone mineral density. Muscle strength and postural stability will also be evaluated, again comparing pre and post-launch data.

Differences from the baseline will be examined in terms of the ability of extremely low-level mechanical stimulation to inhibit the loss of bone quality and quantity. The preservation of muscle strength and postural stability, as based on these mechanical signals will provide a key to the regulatory stimulus in the maintenance of the musculoskeletal system.

Efficacy will be determined as based on the ability of the signal to inhibit bone loss, prevent loss of muscle power and loss of postural stability. Given the ground-based evidence, we anticipate that treated crewmembers will retain bone density and muscle strength regardless of the deleterious consequences of the absence of gravity. Further, it is anticipated that bone loss in the axial skeleton (spine) will be reduced through exposure to the low-level mechanical signal. The experimental system is referred to as VIBE: Vibrational Inhibition of Bone Erosion.

The experimental protocol and device hardware have been evaluated by a number of NASA committees, and the progress of the experiment continues on a path to flight.

Bibliography Type: Description: (Last Updated: 10/22/2009) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Qin Y-X, Xia Y, Lin W, Mittra E, Gruber B, Rubin CT. "Trabecular bone density and strength assessment using non-invasive scanning confocal ultrasound imaging technology. " ASBMR-NIH (NIAMS) Bone Quality Workshop. Bone Quality: What is it and­ can we measure it?, Washington DC, May 2005.

ASBMR-NIH (NIAMS) Bone Quality Workshop. Bone Quality: What is it and­ can we measure it?, May 2005. , May-2005

Abstracts for Journals and Proceedings Judex S, Miller LM, Qin YX, Donahue LR, Rubin C. "Genetic and epigenetic influences on bone quantity and quality. " Symposium on “Comparative Animal Models for Studying Bone & Cartilage Morphogenesis & Growth.” Experimental Biology 2005, San Diego, CA, April 2-6, 2005.

Experimental Biology 2005, Program and Abstracts, Abstract #778.2, April 2005. , Apr-2005

Project Title:  A Low Intensity Mechanical Countermeasure to Prohibit Osteoporosis in Astronauts During Long-Term Spaceflight Reduce
Fiscal Year: FY 2005 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 03/15/2004  
End Date: 03/15/2007  
Task Last Updated: 06/02/2005 
Download report in PDF pdf
Principal Investigator/Affiliation:   Rubin, Clinton  Ph.D. / State University of New York 
Address:  Department of Biomedical Engineering 
Center for Biotechnology 
Stony Brook , NY 11794-2580 
Email: clinton.rubin@sunysb.edu 
Phone: 631-632-8521  
Congressional District:
Web: http://www.bme.sunysb.edu  
Organization Type: UNIVERSITY 
Organization Name: State University of New York 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Judex, Stefan  State University of New York at Stony Brook 
Qin, Yi-Xian  State University of New York at Stony Brook 
Key Personnel Changes / Previous PI: 0
Project Information: Grant/Contract No. NNJ04HD87A 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: ILSRA 2001 
Grant/Contract No.: NNJ04HD87A 
Project Type: FLIGHT 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Osteo:Risk Of Early Onset Osteoporosis Due To Spaceflight (No longer used, July 2020)
Human Research Program Gaps: (1) B01:a) Is there an increased lifetime risk of fragility fractures/osteoporosis in astronauts (Merged with Osteo 2); b) is bone strength completely recovered post-flight (merged with Osteo 3) and does BMD reflect it (Closed); c) what are the risk factors for poor recovery of BMD/bone strength? (Merged with Osteo 4) (IRP Rev D)
Flight Assignment/Project Notes: In flight development phase (not yet manifested)

NOTE: End date changed to 3/15/2007 (from 3/15/2009) for database validation reasons (6/2008)

Task Description: Osteoporosis, the progressive loss of bone density and strength that cripples tens of millions on our planet, distinguishes itself as perhaps the greatest physiologic obstacle to an extended human presence in space. The principal objectives of this proposal are to establish the efficacy of a unique, mechanical countermeasure to inhibit bone loss - and muscle strength- in the lower appendicular skeleton of astronauts and payload specialists during International Space Station missions. Using a ground based model of microgravity, the tail-suspended rat, we have shown that brief exposure (10 minutes) to extremely low magnitude (0.25g, engendering <5 microstrain), high frequency (30-90 Hz) mechanical signals will inhibit the bone loss which typically parallels disuse, even though 10 minutes of full weightbearing failed to curb this loss. Longer-term experiments in sheep have shown this stimulus to be strongly anabolic, increasing bone mineral density, trabecular number and connectivity, and improving bone strength. Preliminary results in post-menopausal women and children with cerebral palsy indicate that this intervention can inhibit, and perhaps reverse, osteoporosis. To determine this intervention's ability to inhibit bone loss - and muscle strength - in people during prolonged space missions, we will subject astronauts, in single let stance, to brief exposures to the low level stimulus (10 minutes at 30 Hz, 0.3g), allowing the contralateral limb to serve as an intra-subject control. The proposal is structured to "piggy-back" onto ongoing flight studies, and thus the assays for efficacy will be determined by collaborative decisions between NASA teams studying the musculoskeletal system. At a minimum, DXA, QCT, and muscle strength measurements will be made both pre- and post- flight. This work represents a critical step in establishing a physiologically based, non-pharmacologic, non-invasive treatment for osteoporosis, for use on Earth or in space.

Research Impact/Earth Benefits: Two clinical studies, evaluating the efficacy of the device, are to be published in the March issue of J. Bone & Mineral Research. In the first study, the intervention is shown to prevent osteoporosis in a group of post-menopausal women. In the second study, the intervention is shown to stimulate bone formation in children with cerebral palsy.

Task Progress & Bibliography Information FY2005 
Task Progress: NASA Status Report, Jan 1 2004 through Dec 31, 2004

PI: Clinton Rubin Graduate Students: Jesse Muir, Beney Lee Lab Technician: Ben Adler

1. Background Summary

This project is focused on studying the anabolic effect of low magnitude, high frequency mechanical stimulation on the load bearing bones of astronauts. A vibrating plate which generates accelerations of 0.3 g peak-to-peak, at a rate of 30 Hz is being used as the source of mechanical stimulation. Exercise and resistance training the have been put in place on MIR and the ISS over the years to help reduce muscle wasting have not stopped the loss of bone that is seen in astronauts (~2%/Month). By having astronauts stand on the plate for 10 minutes per day we hope to show a significant inhibition of the loss of bone due to the lack of gravity.

2. Harness System

The mechanical stimulation is applied to the human body via a harness wore by the subject. Two harnesses were tested in the past year. The main difference between harness one and two was the increased padding in the second harness, and the Velcro adjustability of the first harness. Both harnesses loaded the body in the same manner; two attachment points to the harness along the side of the body, directly under the armpits, at about the level of the waist. Harness one was designed to place a load of 30% of the subject’s body weight when standing and lying down. Harness two was designed to place a load varying from 30% to 60% of the subject’s body weight when lying down. The subjects testing the harnesses ranged in height from 5’0” to 6’4” and in weight from 108lbs to 185lbs. The subject pool of 8 males and 4 females tested harness two for comfort and ease of use. The former had a mixed response from the subjects in terms of comfort. The latter was not an issue for any of the participants; the harness was worn as a jacket, and secured with a front strap. For both of the harnesses, subjects of both genders mentioned an uncomfortable, but not unbearable, pressure mainly in their shoulders and indicated that they would be fine wearing the harness with the load in the 30% and 60% loading conditions. However, several of the women expressed severe discomfort with the harnesses, due to the compression of the chest by the front strap. Similar comments were made about harness one with a 30% load. This discomfort was not present in any of the male subjects. In the two loading conditions we tested, the Velcro adjustment in the back wasn’t used in the various body types of the subjects. In all subjects, the harness only made contact in the back along the top third of the harness. The extra padding in harness two was a definite improvement. One concern that noted was that in zero-g, there will be greater propensity for the body to bend under the application of the load. It may be better to use a hip/shoulder combo harness, such as the TVIS, to decrease the likelihood of bowing under the load in zero g, and it would also remove the need for a separate harness for this countermeasure. We would like to test the TVIS harness to compare it to the other two harnesses in terms of comfort, ease of use, and ensuring the transmission of the signal with a hip/shoulder loading combination versus a shoulder loading combination. Minimizing the mass and volume of equipment needed in the space station is a priority, due to the heavy restriction on payload mass availability and free space in the ISS.

3. Change of protocol from one-leg to two-leg stance

The initial plans for the protocol of the bed rest and astronaut studies had the intervention applied to one leg of the subjects, with the other leg being used as a contra lateral control. By placing an accelerometer on the top plate between the heels of the subject and measuring the acceleration at the head using an accelerometer attached to a bite bar, we could measure the transmission of the signal through the body. When the subject changed from two to one legged stance, there was a drop in transmission of 60% (Figure 1). The protocol has since been changed so that the subjects will be standing with both legs on the plate, and controls will be done with subjects who do not use the plate. Another reason for this is that we wish to look at effects of the vibration on the bones of the spine, and there is no left/right spine to compare. It was also found that the transmission of vibration was dependant on the stance of the subject (Figure 2). When the subject stood with straight legs (locked or relaxed) there was high transmission, but if the legs were bent at a 20 degree angle, or if only one leg was stood on, the transmission dropped dramatically. 4. Measurement of Transmission of Vibration in through the Body To determine how the application of mechanical vibration to the foot of a subject propagates through the body, we attached accelerometers to different points of the body. When the plate was activated, the peak to peak accelerations were measured using tri-axial accelerometers (crossbow inc). Acceleration was measured at the surface of the top plate, and at the shin, hip, and head of the subject. Shin and hip measurements were made by attaching the accelerometer using double sided tape to the skin 5 inches below the knee where the tibia is near the surface, and to the skin above the iliac crest. In both cases, athletic tape was wrapped around the accelerometer and body, making the connection more secure. Measurement at the head was performed using a bite-bar. Percent transmission was defined as the ratio of acceleration at a point in the body to the acceleration of the top plate. The subjects were told to stand on the plate with their feet at shoulder width, and their arms at their sides. There was a large variation between the 10 subjects tested (Figure 3). At the bite bar, there was an average transmission of 68.56% (SD = 20.48). At the hip, transmission was 30.25% (SD = 10.2). At the tibia, transmission was 148.39% with an SD of 61.62. The large variation is contributed to the variation in body types of the subjects. At the hip, there is not a solid interaction between the accelerometer and the bone due to muscle and/or body fat, causing the measured acceleration to be lower than the acceleration of the bone itself.

5. Change in transmission in supine subjects

In the original experimental design, the astronauts were to stand on the plate with one leg, with a load of 30% of their total body weight placed at their shoulders. To simulate microgravity we had the subjects lie on their backs. When the subjects were in a supine position, there was a 50% drop in transmission with both feet on the plate. The drop was smaller in one-legged stance. Our previous work has shown the benefits to a subject who stands freely on the plate for 10 minutes a day. The loss in transmission indicates that a subject in a microgravity environment will be undergoing stimulation of half the magnitude that the standing subjects were under. The magnitude of the stimulation must be increased to levels closer to those seen in a standing subject before the device can be successfully tested in a microgravity environment.

6. Determination of Correct Loading Condition

The application of low magnitude, high frequency mechanical stress to the load bearing bones is being expanded to astronauts in a low to zero-gravity environment. Before the device is to be brought into space, we needed to verify that the application of LMMS to the feet of the subject in a 0g environment would have the same mechanical effect on the body as when standing. To show this, we using a simulated microgravity simulation of a subject in bed rest. The stimulation plate was suspended by a 2 foot chain vertically. The subject was fitted with a harness system which could attach to the plate via springs. These springs applied a force normal to the surface of the plate to the shoulders of the subject, pulling them to the plate. The force applied could be adjusted by adding length to the end of the springs. The subject lay on a moving platform, with their feet on the plate. The applied load to the subject was varied from approximately 30% to 70% of the total weight of the subject. At load intervals, acceleration measurements were taken with the plate activated. Percent Transmission was defined as the ratio of measured acceleration at the body to the acceleration of the plate (set to 0.3 g peak to peak). The percent transmission of the signal varied across subject group (n = 10), though this is expected due to differences in body types and genders. What was found was that as the applied load increased, the transmission of signal increased (Figure 5). When 30% of the subject’s body weight is applied to them, there was approximately 30% transmission. When this load was increased to 60% body weight, the transmission increased to 50%. When the plate was placed on the floor and the subject stood on it under the effects of gravity, there was an average transmission of 62%. This means that with 60% applied body weight to a supine subject, there is 80% of the stresses applied to the body compared to standing. According to the test subject, they would feel comfortable using a 60% BW loading for 10 minutes a day, while higher loads caused discomfort with several subjects. For this reason, we are preceding using 60% body weight at our applied load to supine subjects.

7. Future Studies On February 20th, the first pair of subjects for a 90 day bed rest study will enter the facility at the University of Texas Medical Branch (UTMB) in Galveston Texas. Day 0 of bed rest will be March 4th. We will be involved with four other research teams, studying the effects of unloading as an analog for prolonged space flight. Subjects in the experimental group will be exposed to 10 minutes of vibration each day for the length of the study. Measurements of bone quantity/quality will be performed with DXA, qCT, and ultrasound. Posture control will be determined with a Kistler force plate. Data collected from the other research teams including muscle strength and neurological changes will also be analyzed. The experimental group will be compared to the control group, which is not subjected to the mechanical stimulation. Another study we will be performing will be evaluating the plate and harness system on the KC-135 plane, to study how the plate works in actual microgravity. We will study the effects of microgravity on the transmission of vibration through the body, as well as the ease of use of the device in a micro-g environment. It must be verified that the mechanical stimulation will propagate through the body of the astronauts in microgravity before we can place a plate on the ISS for a long term study.

Bibliography Type: Description: (Last Updated: 10/22/2009) 

Show Cumulative Bibliography Listing
 
 None in FY 2005
Project Title:  A Low Intensity Mechanical Countermeasure to Prohibit Osteoporosis in Astronauts During Long-Term Spaceflight Reduce
Fiscal Year: FY 2004 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 02/01/2003  
End Date: 07/31/2004  
Task Last Updated: 04/03/2006 
Download report in PDF pdf
Principal Investigator/Affiliation:   Rubin, Clinton  Ph.D. / State University of New York 
Address:  Department of Biomedical Engineering 
Center for Biotechnology 
Stony Brook , NY 11794-2580 
Email: clinton.rubin@sunysb.edu 
Phone: 631-632-8521  
Congressional District:
Web: http://www.bme.sunysb.edu  
Organization Type: UNIVERSITY 
Organization Name: State University of New York 
Joint Agency:  
Comments:  
Project Information: 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: ILSRA 2001 
Project Type: FLIGHT 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Osteo:Risk Of Early Onset Osteoporosis Due To Spaceflight (No longer used, July 2020)
Human Research Program Gaps: (1) B01:a) Is there an increased lifetime risk of fragility fractures/osteoporosis in astronauts (Merged with Osteo 2); b) is bone strength completely recovered post-flight (merged with Osteo 3) and does BMD reflect it (Closed); c) what are the risk factors for poor recovery of BMD/bone strength? (Merged with Osteo 4) (IRP Rev D)
Task Description: Osteoporosis, the progressive loss of bone density and strength that cripples tens of millions on our planet, distinguishes itself as perhaps the greatest physiologic obstacle to an extended human presence in space. The principal objectives of this proposal are to establish the efficacy of a unique, mechanical countermeasure to inhibit bone loss - and muscle strength- in the lower appendicular skeleton of astronauts and payload specialists during International Space Station missions. Using a ground based model of microgravity, the tail-suspended rat, we have shown that brief exposure (10 minutes) to extremely low magnitude (0.25g, engendering <5 microstrain), high frequency (30-90 Hz) mechanical signals will inhibit the bone loss which typically parallels disuse, even though 10 minutes of full weightbearing failed to curb this loss. Longer-term experiments in sheep have shown this stimulus to be strongly anabolic, increasing bone mineral density, trabecular number and connectivity, and improving bone strength. Preliminary results in post-menopausal women and children with cerebral palsy indicate that this intervention can inhibit, and perhaps reverse, osteoporosis. To determine this intervention's ability to inhibit bone loss - and muscle strength - in people during prolonged space missions, we will subject astronauts, in single let stance, to brief exposures to the low level stimulus (10 minutes at 30 Hz, 0.3g), allowing the contralateral limb to serve as an intra-subject control. The proposal is structured to "piggy-back" onto ongoing flight studies, and thus the assays for efficacy will be determined by collaborative decisions between NASA teams studying the musculoskeletal system. At a minimum, DXA, QCT, and muscle strength measurements will be made both pre- and post- flight. This work represents a critical step in establishing a physiologically based, non-pharmacologic, non-invasive treatment for osteoporosis, for use on Earth or in space.

Research Impact/Earth Benefits: Two clinical studies, evaluating the efficacy of the device, are to be published in the March issue of J. Bone & Mineral Research. In the first study, the intervention is shown to prevent osteoporosis in a group of post-menopausal women. In the second study, the intervention is shown to stimulate bone formation in children with cerebral palsy.

Task Progress & Bibliography Information FY2004 
Task Progress: Two clinical studies, evaluating the efficacy of the device, are to be published in the March issue of J. Bone & Mineral Research. In the first study, the intervention is shown to prevent osteoporosis in a group of post-menopausal women. In the second study, the intervention is shown to stimulate bone formation in children with cerebral palsy.

Bibliography Type: Description: (Last Updated: 10/22/2009) 

Show Cumulative Bibliography Listing
 
Articles in Peer-reviewed Journals Ward K, Alsop C, Caulton J, Rubin C, Adams J, Mughal Z. "Low magnitude mechanical loading is osteogenic in children with disabling conditions." J Bone Miner Res. 2004 Mar;19(3):360-9. Epub 2004 Jan 27. PMID: 15040823 , Mar-2004
Articles in Peer-reviewed Journals Rubin C, Recker R, Cullen D, Ryaby J, McCabe J, McLeod K. "Prevention of postmenopausal bone loss by a low-magnitude, high-frequency mechanical stimuli: a clinical trial assessing compliance, efficacy, and safety." J Bone Miner Res. 2004 Mar;19(3):343-51. Epub 2003 Dec 22. PMID: 15040821 , Mar-2004