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Project Title:  Promoting Sensorimotor Response Generalizability: A Countermeasure to Mitigate Locomotor Dysfunction After Long-Duration Spaceflight Reduce
Fiscal Year: FY 2008 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 05/01/2000  
End Date: 09/30/2008  
Task Last Updated: 01/15/2009 
Download report in PDF pdf
Principal Investigator/Affiliation:   Bloomberg, Jacob J. Ph.D. / NASA Johnson Space Center 
Address:  NASA Emeritus Scientist, Biomedical Research and Environmental Sciences Div 
2101 NASA Parkway, SK272 
Houston , TX 77058-3607 
Email: jacob.j.bloomberg@nasa.gov 
Phone: 281-483-0436  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Mulavara, Ajitkumar  University Space Research Association 
Cohen, Helen  Baylor College of Medicine 
Peters, Brian  Wyle Life Sciences 
Miller, Chris  Wyle Life Sciences 
Kozlovskaya, Inessa  Institute for Biomedical Problems 
Project Information: Grant/Contract No. None 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: 98-HEDS-02 
Grant/Contract No.: None 
Project Type: FLIGHT 
Flight Program: ISS 
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) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Flight Assignment/Project Notes: ISS

NOTE: end date changed to 9/30/2008, from 9/01/2010, per PI and S. McCollum/JSC (10/08)

In flight development phase (data collection has begun)

Task Description: Following their return to Earth, astronauts experience disturbances in their ability to walk and maintain postural stability due to neural adaptation to the microgravity conditions of space flight. These changes can impact mission objectives during planetary EVAs and may impair emergency vehicle egress capability. The goal of this project was to characterize the effects of space flight on the control of locomotion and develop and test an inflight balance and gait training program that would facilitate recovery of functional mobility after space flight. Due to logistic issues the inflight hardware that was to be used to provide the gait adaptability training on ISS treadmill exercise was not flown to the ISS. This report focuses on the pre/postflight component of this study that characterized the effects of long-duration space flight on the control of locomotion and dynamic visual acuity.

We collected pre and postflight locomotion data on crewmembers from ISS Expeditions 5-12. Locomotor function was assessed before and after space flight using two tests of gait function. The Integrated Treadmill Locomotion Test (ITLT) characterized alterations in the integrated function of multiple sensorimotor sub-systems. Subjects walked on a motorized treadmill while we assessed changes in postural stability, head-trunk coordination, dynamic visual acuity and lower limb coordination strategies. The Functional Mobility Test (FMT) provided a corresponding assessment of the functional and operational changes in locomotor function by testing subjects’ ability to negotiate an obstacle course placed over a medium-density foam floor.

Results from the FMT indicate that adaptation to space flight led to a 62% increase in time to traverse the obstacle course on one day after return, and recovery of function took an average of 11 days after return. Results from the ITLT showed that subjects exhibited postflight changes in head-trunk coordination, toe clearance and gait cycle timing during treadmill locomotion Dynamic visual acuity was decreased postflight followed by an improvement in performance during the post flight recovery period.

An analysis of the relationship between inflight treadmill usage characteristics and postflight functional mobility performance revealed that subjects who exercised on the iRED with greater body loading had enhanced postflight (R+1) functional mobility performance.

Research Impact/Earth Benefits: The data obtained in this study will aid in the design of a countermeasures system used to support exploration-class space missions. The operational version of this countermeasure will use a virtual reality (VR) system coupled with multi-direction treadmill along with haptic glove devices that will allow the user to walk in any direction and perform complex manual tasks in a varied and interesting virtual environment. This type of fusion interface, which incorporates both virtual and non-virtual devices across sensory modalities, produces multi-sensory, virtually augmented, synthetic environments. These synthetic environments can serve as pre-and inflight training tools providing sufficient sensorimotor challenge to crewmembers to maximize their motor response adaptability, facilitating the adaptive transition to partial or unit gravity.

Within the context of locomotor functional training and rehabilitation, it is clear that an enriched and challenging environment provided by virtual reality devices provides the optimal conditions to explore variability and in that exploration increase adaptability of motor function. Indeed, the concept of employing virtual reality technology as a tool for rehabilitation has become a topic of great interest among a number of researchers. A collateral benefit of the application virtual reality technology, in this context, will be to make gait training programs for both space flight and rehabilitation more interesting, ultimately leading to increased adherence to prescribed training regimens.

As people age on Earth, they sometimes experience instabilities in standing and walking. The development of unique walking and balance training procedures like the ones proposed in this study can be used to help prevent falling and injury in the elderly and clinical vestibular population. We have pursued this line of research in collaboration with Drs. Ronita Cromwell and Regina Buccello-Stout at the University of Texas Medical Branch in Galveston. This associated study compared a group of elders receiving the specialized treadmill adaptability training with a group that received the treadmill training only. Results from this study showed significantly improved gait function in elders that received the sensorimotor adaptability training (Buccello-Stout et al., 2008) . This study clearly demonstrated the general utility of the training method beyond the NASA applications.

Task Progress & Bibliography Information FY2008 
Task Progress: Conclusions

The following conclusions address the risks and research gaps outlined in NASA's Human Research Program (HRP) Integrated Research Plan

Addressing Research Gap SM2:

"What is the time course of recovery of sensorimotor function after long-duration space flight?"

1) Conclusion: Adaptation to long-duration space flight led to a 62% increase in time to complete Functional Mobility Test obstacle course one day after landing (R+1). Recovery to pre-flight scores took an average of 11 days after landing.

Implications: During the acute phase of adaptation to novel gravitational environments on exploration class missions sensorimotor disturbances will probably disrupt the ability to ambulate and perform functional tasks. These disturbances are likely to impair performance of complex tasks and could, therefore, affect astronaut safety and ultimate mission success. Also, current concepts for the crew return via the Constellation’s Orion spacecraft after long-duration space flight include a water landing. This poses a unique risk to deconditioned and sensorimotor impaired crewmembers if an emergency egress is required soon after landing.

Forward Work: Results obtained from the Functional Mobility Test served to motivate the design of the Functional Task Test (DSO 640), a pre/postflight battery of tests that will be used to assess performance of astronauts on functional tasks that are representative of critical mission tasks for lunar and Mars operations.

2) Conclusion: Recovery of functional mobility after long-duration space flight is composed of two distinct but interrelated motor learning processes: i) rapid on-line strategic change characterized by immediate onset after landing and ii) slower adaptive change requiring days to complete after landing.

Implications: Postflight recovery in functional mobility involves both strategic and adaptive mechanisms and that there is dynamic interplay between these two processes. Adaptability training programs currently being developed as a countermeasure to facilitate adaptive transition to novel g environments should be designed to engage both strategic and adaptive systems to fully promote rapid and complete recovery of sensorimotor function.

Forward Work: Current ground-based studies being conducted in our laboratory are focusing on developing adaptability training programs that include both gait and manual control training. In addition this research is investigating the retention capabilities of adaptability training allowing this type of training to be conducted preflight and therefore reducing the requirement for an inflight training component saving inflight crewtime and upmass hardware requirements.

Addressing HRP Risk(s):

Risk of Impaired Ability to Maintain Control of Vehicles and Other Complex Systems

3) Conclusion: Postflight (R+1) changes in gaze control produced decreases in dynamic visual acuity (DVA) during walking. For some subjects the decrement was greater than the mean acuity decrement seen in a population of vestibularly impaired patients collected using a similar protocol. The population mean showed a consistent improvement in DVA performance during the two-week postflight recovery period.

Implications: While these data show changes in the ability of the crewmembers to see visual targets clearly while walking following space flight, these measures likely underestimate the decrements in visual performance that could be experienced during and immediately following landing. First, with the exception of one crewmember all of the DVA data were collected no earlier than 24 hrs after the landing. Given the rapid re-adaptation of gaze control we can infer that the decrement in visual acuity at landing was significantly higher. Also, walking is an active, well practiced, activity and therefore feed-forward control mechanisms facilitate the process of producing compensatory eye movements. The walking DVA test therefore underestimates the amount of decrement in visual performance that would be expected during passive, unpredictable motion that would occur in a landing vehicle.

Forward Work: Post-flight neurological exams conducted by flight surgeons have rated gaze and ocular symptoms from mild to severe in over 50% of returning Shuttle astronauts. These observations are consistent with the decrements in visual acuity during locomotion described in this report. The Sensorimotor Discipline Implementation Team has recommended the addition of a “field” test of dynamic visual acuity that could be incorporated in the post-flight examinations. Incorporation of a post-flight dynamic visual performance assessment has been assigned a high priority as a research gap for the Sensorimotor Discipline. This research should focus on the development of a portable system that will provide passive body motion (i.e. seated subject on a motion base) while subjects perform tests of visual performance. Astronauts should be tested as soon as possible after landing to assess the early effects of gaze dysfunction related to sensorimotor adaptation. This will allow a better determination of the potential impacts of changes in visual acuity on landing performance. These data will inform the Constellation Program about expected changes in visual performance and will provide requirement for lander display panels.

4) Conclusion: Subjects exhibited postflight changes in head-trunk coordination, toe clearance, gait cycle timing and torso stability during treadmill locomotion.

Implications: Changes in multiple sensorimotor control systems as a result of exposure to space flight leads to decrement in postflight functional mobility.

Forward Work: The Functional Task Test (FTT, DSO 640) will allow better definition of the linkage between physiological change and functional performance including across several physiological systems (sensorimotor, cardiovascular, muscle performance).

Addressing Gap SM1:

"Relationship between the mode of in-flight exercise and post-flight sensorimotor performance?"

5) Conclusion: Relating the post-flight performance on the Functional Mobility Test with in-flight exercise produced one major observation:

Subjects who performed squat exercises on the iRED with greater loads had enhanced post-flight (R+1) functional mobility performance.

Implications: The association between loads lifted during squat exercises using the iRED and post-flight FMT performance could be due to the challenge offered to the postural muscles during these exercises on orbit with increased load. This provides enhanced postural variability at higher loads producing a static and dynamic balance challenge and perhaps serves to improve post-flight locomotor control. Current ground-based studies being conducted in our lab are investigating the role of increasing support surface instability during various resistance and locomotor exercises as a modality to enhance adaptability of sensorimotor function. Support surface variation during resistance and treadmill gait training is achieved by mounting a resistance exercise device and or a treadmill on a six-degree-of-freedom motion device. This allows motion of the support surface in multiple degrees of freedom and serves as a test bed to investigate novel resistance and treadmill training techniques for eventual application as part the nominal astronaut pre- or in-flight exercise training programs.

Forward Work: It will be useful to examine the relationship between other in-flight exercise modalities (cycle ergometer, upper body resistive exercise) and post-flight functional mobility performance to determine if a relationship exists. The current in-flight exercise data set includes only average data from US crewmembers over the entire duration of the mission. The exercise prescriptions to US crewmembers are graded over the duration of mission with the intensity (especially loading) and duration increased towards the end of the mission. Hence, the above analysis may be over conservative in its estimates and should be extended with data over separate in-flight periods to confirm the relationships observed in the present study.

Bibliography Type: Description: (Last Updated: 05/21/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Miller C, Peters B, Brady R, Mulavara A, Richards J, Hayat M, Bloomberg J. "Effects of long-duration space flight on toe clearance during treadmill walking." Gait II session, 2008 North American Congress on Biomechanics, Ann Arbor, MI, August, 2008.

2008 North American Congress on Biomechanics, Ann Arbor, MI, August, 2008. , Aug-2008

Abstracts for Journals and Proceedings Bloomberg JJ, Mulavara AP, Peters BT, Miller CA, Richards JT, Brady R, Cohen HS, Kozlovskaya IB. "Motor learning processes mediating recovery of functional mobility after space flight." Voluntary Movement: Plasticity II session, Annual Meeting of the Society for Neuroscience, Washington, DC, November 15-19, 2008.

Annual Meeting of the Society for Neuroscience, Washington, DC, November 15-19, 2008. , Nov-2008

Abstracts for Journals and Proceedings Bloomberg JJ, Peters BT, Mulavara AP, Ruttley TM, Miller CA, Brady R, Cohen HS. "Development of sensorimotor adaptability training programs." NASA Human Research Program Investigators' Workshop, Houston, TX, February 2008.

NASA Human Research Program Investigators' Workshop, Houston, TX, February 2008. , Feb-2008

Abstracts for Journals and Proceedings Mulavara AP, Cohen HS, Peters BT, Miller CA, Brady R, Bloomberg JJ. "Locomotor Dysfunction after Spaceflight: Characterization and Countermeasure Development." Motor Control session, Houston Society for Engineering in Medicine and Biology 23rd Annual Houston Conference on Biomedical Engineering Research, Houston, TX, 9-10 February 2007.

Houston Society for Engineering in Medicine and Biology 23rd Annual Houston Conference on Biomedical Engineering Research, Houston, TX, 9-10 February 2007. , Feb-2007

Abstracts for Journals and Proceedings Bloomberg JJ, Mulavara AP, Peters BT, Cohen HS, Miller CA, Brady R, Warren LE, Ruttley TM, Kozlovskaya IB. "Development of training programs to optimize planetary ambulation." NASA Human Research Program Investigators' Workshop, Houston, Texas, February 12–14, 2007.

NASA Human Research Program Investigators' Workshop, Houston, Texas, February 12–14, 2007. , Feb-2007

Abstracts for Journals and Proceedings Peters BT, Van Emmerik R, Brady R, Bloomberg JJ. "Visual acuity during treadmill walking." Visual Functions session, the18th Meeting of the International Society for Posture and Gait Research, Burlington, VT, July 15-18, 2007.

18th Meeting of the International Society for Posture and Gait Research, Burlington, VT, July 15-18, 2007. , Jul-2007

Abstracts for Journals and Proceedings Miller C, Peters B, Brady R, Mulavara A, Warren L, Feiveson A, Bloomberg J. "Comparison of two alternate methods for tracking toe trajectory." Locomotion session, 31st Annual Meeting of the American Society of Biomechanics, Stanford University, Palo Alto, CA, August 2007.

31st Annual Meeting of the American Society of Biomechanics, Stanford University, Palo Alto, CA, August 2007. , Aug-2007

Articles in Peer-reviewed Journals Miller CA, Feiveson AH, Bloomberg JJ. "Effects of speed and visual-target distance on toe trajectory during the swing phase of treadmill walking." Journal of Applied Biomechanics, 2009 Feb;25(1):32-42. PubMed PMID: 19299828 , Feb-2009
Project Title:  Promoting Sensorimotor Response Generalizability: A Countermeasure to Mitigate Locomotor Dysfunction After Long-Duration Spaceflight Reduce
Fiscal Year: FY 2007 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 05/01/2000  
End Date: 09/30/2008  
Task Last Updated: 05/18/2007 
Download report in PDF pdf
Principal Investigator/Affiliation:   Bloomberg, Jacob J. Ph.D. / NASA Johnson Space Center 
Address:  NASA Emeritus Scientist, Biomedical Research and Environmental Sciences Div 
2101 NASA Parkway, SK272 
Houston , TX 77058-3607 
Email: jacob.j.bloomberg@nasa.gov 
Phone: 281-483-0436  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Mulavara, Ajitkumar  Ph.D. Baylor College of Medicine, National Space Biomedical Research Institute 
Cohen, Helen  Baylor College of Medicine 
Peters, Brian  Wyle Life Sciences 
Project Information: Grant/Contract No. None 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: 98-HEDS-02 
Grant/Contract No.: None 
Project Type: FLIGHT 
Flight Program: ISS 
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) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Flight Assignment/Project Notes: ISS

NOTE: end date changed to 9/30/2008, from 9/01/2010, per PI (10/08)

In flight development phase (data collection has begun)

Task Description: Following their return to Earth, astronauts experience disturbances in their ability to walk and maintain postural stability due to neural adaptation to the microgravity conditions of space flight. These changes can impact mission objectives during planetary EVAs and may impair emergency vehicle egress capability. At present, no operational countermeasure is available to mitigate these risks by facilitating rapid sensorimotor re-adaptation to gravitational environments. Therefore, the goal of this project is to develop a balance and gait training program that will facilitate recovery of functional mobility after space flight.

There is strong evidence in both the motor learning and clinical rehabilitation literature, that training with task variability along with exposure to repeated sensorimotor adaptive challenges leads to faster adaptation to new environments and readaptation to the normal environment. During this type of training the subject gains experience producing the appropriate adaptive behavior under a variety of sensory conditions and balance challenges. As a result of this training a subject learns to solve a class of balance and walking problems, rather than producing a single solution to one problem. Therefore, the subject gains the ability to "learn to learn" under a variety of conditions that challenge the balance and walking control systems. This study will develop an in-flight countermeasure built around the ISS treadmill exercise activities. By manipulating the sensory conditions of exercise (by varying visual flow patterns during walking) and modifying the task constraints (reading, head movements) this training regimen will systematically and repeatedly promote adaptive change in walking performance improving the ability of the astronaut to adapt to a novel gravity environment. It is anticipated that this training regimen will facilitate neural adaptation to planetary gravitational environments after space flight. Adaptability training may be one of the most comprehensive and cost effective sensorimotor countermeasures as the training can be embedded into nominal exercise programs without incurring a significant increase in crew time commitment.

The Mobility protocol is performed by two sets of ISS subjects comprising Control and Experimental groups. All participating subjects (Control and Experimental) perform two tests of locomotor performance both pre and postflight: the Integrated Treadmill Locomotion Test and the Functional Mobility Test. The Experimental Group will also perform the in-flight training protocol throughout the increment and an inflight test of Dynamic Visual Acuity. Comparisons will then be made between recovery rates in the Control vs. Experimental groups.

Operational Protocols

Gait Adaptability Training Protocol

Locomotion is controlled through the integration of multiple sensory inputs, including vision. Visual inputs provide us with important cues for orientation and self-movement perception during locomotion. The patterned visual motion seen during self-movement constitutes the optic flow field that provides perceptual cues about self-movement and environmental structure. Exposure to visual flow variation is an effective way to challenge the balance and gait control system. For this study a visual display system (Mobility Graphics Display, MGD) was developed to provide variation in visual flow during regular treadmill exercise. The MGD is mounted at eye level over the ISS treadmill (TVIS, Treadmill with Vibration and Isolation System). Crewmembers will see a visual representation of a virtual scene varying in yaw, pitch and roll motions. Subjects will be exposed to this stimulus during the 10 minute warm up and cool down periods of their regular inflight treadmill exercise session.

The virtual visual scenes presented on the MGD were created using graphic modeling software (3ds max 4; Discreet, Montreal, Quebec, Canada) and rendered using virtual environment software (VRUT Version 2.5, Python Version 2.0) on a PC computer (2.2 GHz, Intel Pentium 4 processor, nVIDIA Quadro2 EX graphics card). Scenes are rotated or oscillated or moved linearly to depict motion in all six degrees of freedom relative to space. The scenes consist of a cubical room or an outdoor scene of a park with simulated dimensions rich in polarizing visual content. The cubical room includes distinctive markings on the floor and ceiling and realistic texture-mapped objects such as trees, desks, chairs, and gravity-cued pictures. The subject’s simulated eye point is placed such that it seems as if the subject is walking down a hallway or through a walkway in the park at a fixed rate. Simulated scene dimensions were chosen to maximize desired perceptual effects as determined from pilot studies. These multiple scenes were categorized depending on perceived degree of difficulty as determined by ground-based studies ranging from low to high and would be presented to the user in various combinations by an apriori determined training schedule. These scenes were part of a software package that was developed to interact with the subjects with a graphical user interface that was intuitive and easy to use.

Pre and Postflight Testing

Locomotor function in both Control and Experimental groups are assessed before and after space flight using two tests of gait function. The Integrated Treadmill Locomotion Test characterizes alterations in the integrated function of multiple sensorimotor sub-systems. This test calls for subjects to walk on a motorized treadmill while we assess changes in dynamic postural stability, head-trunk coordination, visual acuity and lower limb coordination strategies. The Functional Mobility Test provides a corresponding assessment of the functional and operational changes in locomotor function by testing subject’s ability to negotiate an obstacle course placed over a medium-density foam floor.

Test 1: Integrated Treadmill Locomotion Test

Subjects walk at 6.4 km/h on a motorized treadmill while performing a visual task consisting of identifying the position of the gap in the letter “C” that is presented centrally on a laptop computer positioned 4 meters in front at eye level. Each trial lasts approximately 30 seconds and is repeated four times.

Subjects also walk at 6.4 km/h on the treadmill while performing the same visual task described above but in this case with the letter “C” is presented centrally on a micro-display positioned 50 centimeters in front at eye level. Each of these trials last approximately 30 seconds and are repeated four times.

While subjects are walking on the treadmill and performing the visual task 3-dimensional full-body motion data are acquired using a video-based motion analysis system; gait cycle timing is measured using foot switches placed in the shoes and dynamic visual acuity is assessed by the visual task described above.

Test 2: Functional Mobility Test

To determine if a behavior like locomotion is altered by space flight it is important to define metrics of performance that relate to functional activities. The Functional Mobility Test (FMT) serves as a global test of locomotor performance that when implemented along with other physiological tests can be used to link changes in underlying sensorimotor systems with operational performance relevant to returning astronauts. To perform the FMT crewmembers walked at a preferred pace through an obstacle course set up on a base of 10 cm thick medium density foam (Sunmate Foam, Dynamic Systems, Inc., Leicester, NC). The 6.0m X 4.0m course consisted of several pylons made of foam; a Styrofoam barrier 46.0cm high that crewmembers stepped over; and a portal constructed of two Styrofoam blocks, each 31cm high, with a horizontal bar covered by foam and suspended from the ceiling which was adjusted to the height of the crewmember’s shoulder. The portal required crewmembers to bend at the waist and step over a barrier simultaneously. All obstacles were lightweight, soft and easily knocked over. Crewmembers were instructed to walk through the course as quickly and as safely as possible without touching any of the objects on the course. This task was performed three times in the clockwise direction and three times in the counterclockwise direction that was randomly chosen. The dependent measures for each trial were: time to complete the course (seconds) and the number of obstacles touched or knocked down.

Research Impact/Earth Benefits: As people age on Earth, they sometimes experience instabilities in standing and walking. The development of unique walking and balance training procedures like the ones proposed in this study can be used to help prevent falling and injury in the elderly population. An associated study being conducted at the University of Texas Medical Branch, funded by the NASA Graduate Student Research Program, is currently investigating this issue.

Task Progress & Bibliography Information FY2007 
Task Progress: Summary of Results to Date

As part of the effort to evaluate the gait adaptability-training regimen, we have collected pre and post flight locomotion data from International Space Station Expeditions 5-12 (n =18) who will serve as the Control group.

Functional Mobility Test (FMT)

The time to complete (TCC) the FMT course data from all 18 subjects for each post flight day were averaged and collated for further analysis. A logarithmic curve using a least squares procedure was fit through these points and its intersection with the average ± 95% confidence interval of the mean preflight TCC across all subjects was calculated to determine the duration of time taken to recover functional locomotor performance. Results from FMT of the 18 subjects indicate that the adaptation to space flight led to a significant increase in time to traverse the obstacle course and recovery of function took an average of 2 weeks after their return.

Evaluation of TCC for each individual subject over the days of re-adaptation revealed the presence of two distinct postflight recovery patterns: 1) a rapid learning curve over the first six FMT trials conducted on R+1 and 2) a slower recovery pattern across days (R+1 - R+25). We infer that the learning curve shown within each test day represent strategic learning while the longer recovery period represent adaptive remodeling in sensorimotor function. Subjects were then classified into two groups, the Slow Recovery Group (SRG) and the Fast Recovery Group (FRG), based on the significance of the curve fit results for the data obtained on one day after landing. Comparing the average recovery rates for one day after landing (R+1) and the overall rate (R+1 - R+25) across the subjects in the two groups we see that subjects who demonstrate a fast initial strategic learning effect on R+1 also show a faster overall recovery during the R+1 - R+25 recovery period.

Integrated Treadmill Locomotion Test

The movement of head and torso body segments was measured using a video-based motion measurement system. Six time synchronized CCD cameras, sampling at 60 Hz, were used to obtain the three dimensional positions of light weight retro-reflective markers placed on these body segments. The 3D positions of these markers were used to calculate the head and torso angular orientations. Each 30-second trial period for each of these movement parameters was subjected to Fourier analysis. The amplitude of the predominant frequency in the signals was measured to estimate the contributions of vestibular reflexive mechanisms to head movement control. The temporal variations of the head and trunk roll, pitch and yaw angular orientations were time normalized over the entire gait cycle - heel strike (0%) to the following heel strike (100%) of the right foot - at one percent gait cycle intervals. These time normalized waveforms were used to determine the cross correlation functions between the head and trunk movements about the roll (HRTR), pitch (HPTP) and the yaw (HYTY) planes. The maximum values closest to the zero phase lag were quantified as the estimate of coordination between the head and trunk movements. Each measurement was averaged and its 95% confidence interval (CI) was determined across the six trials pre and post flight. Subjects were then classified into three groups based on the overlap of the Pre and Post flight confidence limits: A) significantly increased, B) no change, and C) significantly decreased, relative to pre-flight. Analyzing the each subject’s amplitude of the predominant frequency for the head angular roll, pitch and yaw orientations with respect to space (deg) we found that after space flight, subjects showed a significant change in the head roll and pitch orientations, respectively, during walking. In contrast, only smaller percentage of subjects showed a significant change in head movement magnitudes in the yaw orientation, during walking. Analyzing each subjects maximum cross correlation values for the HRTR, HPTP and the HYTY functions we found similar results in that after space flight, subjects showed a significant change in coordination between the head and torso in the roll and pitch planes, respectively, with minimal changes in the yaw plane, during walking.

Dynamic visual acuity (DVA) data collected following their long-duration (~6 months) stays in space showed a decrement in walking acuity. For some subjects the decrement was greater than the mean acuity decrement seen in a population of vestibularly impaired patients collected using a similar protocol. In summary, head movements during locomotion showed postflight changes predominantly in the pitch and roll planes presumably due to the central reinterpretation of otolith information. Dynamic visual acuity was decreased followed by an improvement in performance during the post flight recovery period. Adaptation to space flight led to a 50% increase in time to traverse the obstacle course on R+1, and recovery of function took an average of 2 weeks after return. Importantly, alterations in kinematics and dynamic visual acuity were accompanied by commensurate changes in functional mobility.

CONCLUSIONS

Recovery of functional mobility after long-duration space flight is composed of two distinct processes: a rapid on-line strategic change characterized by immediate onset after landing and a slower adaptive change requiring days to complete after landing. Therefore the composition and timing of sensory challenges experienced during gait training sessions need to be optimized to facilitate the acquisition of rapid on-line strategic changes. Further, training that facilitates rapid reorganization of sensorimotor function will allow improved functional performance during the early phase of readaptation to a planetary g-environment.

Bibliography Type: Description: (Last Updated: 05/21/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Mulavara AP, Peters BT, Cohen HS, Richards JT, Miller CA, Brady R, Warren LE, Kozlovskaya IB, Bloomberg JJ. "Development of Testing Methodologies to Evaluate Postflight Locomotor Performance." Presented at the The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, Noordwijk, the Netherlands, June 7-9, 2006.

The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, ESA, June 2006. , Jun-2006

Abstracts for Journals and Proceedings Bloomberg JJ, Mulavara AP, Peters BT, Cohen HS, Richards JT, Miller CA, Brady R, Warren LE, Ruttley TM, Kozlovskaya IB. "Development of a Countermeasure to Mitigate Postflight Locomotor Dysfunction. " Presented at the The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, Noordwijk, the Netherlands, June 7-9, 2006.

The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, ESA, June 2006. , Jun-2006

Abstracts for Journals and Proceedings Richards JT, Mulavara AP, Ruttley TM, Peters BT, Warren LE, Bloomberg JJ. "Relative Contributions of Strategic and Adaptive Control Mechanisms in Plastic Recalibration of Locomotor Heading Direction." Presented at the The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, Noordwijk, the Netherlands, June 7-9, 2006.

The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, ESA, June 2006. , Jun-2006

Abstracts for Journals and Proceedings Warren LE, Mulavara AP, Peters BT, Cohen HS, Richards JT, Miller CA, Brady R, Ruttley TM, Bloomberg JJ. "Assessment of Postflight Locomotor Performance Utilizing a Test of Functional Mobility: Strategic and Adaptive Responses. " Presented at the The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, Noordwijk, the Netherlands, June 7-9, 2006.

The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, ESA, June 2006. , Jun-2006

Abstracts for Journals and Proceedings Peters BT, Mulavara AP, Brady R, Miller CA, Warren LE, Richards JT, Cohen HS, Bloomberg JJ. "The Use of Dynamic Visual Acuity as a Functional Test of Gaze Stabilization Following Space Flight. " Presented at the The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, Noordwijk, the Netherlands, June 7-9, 2006.

The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, ESA, June 2006. , Jun-2006

Abstracts for Journals and Proceedings Cohen HS, Kimball KT, Bloomberg JJ, Mulavara AP. "Usefulness of current standardized balance tests for determining if balance-impaired individuals differ from normals. " Presented at the The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, Noordwijk, the Netherlands, June 7-9, 2006.

The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, ESA, June 2006. , Jun-2006

Abstracts for Journals and Proceedings Oddsson LIE , Bloomberg JJ, Zemkova E, Dwyer A, Chow A, Meyer P, Wall C 3rd. "Development of In-Flight Countermeasures with Multimodal Effects - Muscle Strength and Balance Function." Presented at the The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, Noordwijk, the Netherlands, June 7-9, 2006.

The Seventh Symposium on the Role of the Vestibular Organs in Space Exploration, ESA, June 2006. , Jun-2006

Abstracts for Journals and Proceedings Mulavara AP, Cohen HS, Peters BT, Miller CA, Brady R, Bloomberg JJ. "Locomotor Dysfunction after Spaceflight: Characterization and Countermeasure Development." HSEMB 2006 meeting, University of Houston, Houston, TX, February 9-10, 2006.

HSEMB 2006 meeting, February 2006. , Feb-2006

Abstracts for Journals and Proceedings Cohen HS, Kimball KT, Mulavara AP, Paloski WH, Bloomberg JJ. "Usefulness of Current Balance Tests for Identifying Balance-Impaired Individuals. " Presented at the 30th MidWinter Meeting, ARO, Denver, Colorado, Feb. 10 - 15, 2007.

ARO (Association for Research in Otolaryngology) MidWinter Meeting, February 2007. , Feb-2007

Abstracts for Journals and Proceedings Bloomberg JJ, Mulavara AP, Peters BT, Cohen HS, Richards JT, Miller CA, Brady R, Warren LE, Ruttley TM, Kozlovskaya IB. "Development of training programs to optimize planetary ambulation. " Presented at the NASA Human Research Program Investigators' Workshop, Houston, Texas, February 12–14, 2007.

NASA Human Research Program Investigators' Workshop, February 2007. , Feb-2007

Articles in Peer-reviewed Journals Peters BT, van Emmerik RE, Bloomberg JJ. "Stride cycle influences on goal-directed head movements made during walking." Gait Posture. 2006 Aug;24(1):70-6. PMID: 16099655 , Aug-2006
Articles in Peer-reviewed Journals Moore ST, MacDougall HG, Peters BT, Bloomberg JJ, Curthoys IS, Cohen HS "Modeling locomotor dysfunction following spaceflight with Galvanic vestibular stimulation. " Exp Brain Res. 2006 Oct;174(4):647-59. PMID: 16763834 , Oct-2006
Articles in Peer-reviewed Journals Richards JT , Mulavara AP, Bloomberg JJ. "The interplay between strategic and adaptive control mechanisms in plastic recalibration of locomotor function. " Exp Brain Res. 2007 Apr;178(3):326-38. PMID: 17061092 , Apr-2007
Dissertations and Theses Peters B. "Visual Acuity While Walking and the Collective Contribution of Non-Ocular Gaze Mechanisms." Dissertation, University of Massachusetts, Amherst, February 2006. , Feb-2006
Dissertations and Theses Ruttley T. "The role of body load-regulating mechanisms in gaze stabilization during locomotion." Dissertation, The University of Texas Medical Branch at Galveston, Galveston, February 2007. , Feb-2007
Dissertations and Theses Buccello-Stout R. "The effects of sensorimotor adaptation training on functional mobility in older adults." Dissertation, The University of Texas Medical Branch at Galveston, Galveston, January 2007. , Jan-2007
Project Title:  Promoting Sensorimotor Response Generalizability: A Countermeasure to Mitigate Locomotor Dysfunction After Long-Duration Spaceflight Reduce
Fiscal Year: FY 2006 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 05/01/2000  
End Date: 09/30/2008  
Task Last Updated: 05/24/2007 
Download report in PDF pdf
Principal Investigator/Affiliation:   Bloomberg, Jacob J. Ph.D. / NASA Johnson Space Center 
Address:  NASA Emeritus Scientist, Biomedical Research and Environmental Sciences Div 
2101 NASA Parkway, SK272 
Houston , TX 77058-3607 
Email: jacob.j.bloomberg@nasa.gov 
Phone: 281-483-0436  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Mulavara, Ajitkumar  Ph.D. Baylor College of Medicine, National Space Biomedical Research Institute 
Cohen, Helen  Baylor College of Medicine 
Project Information: Grant/Contract No. None 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: 98-HEDS-02 
Grant/Contract No.: None 
Project Type: FLIGHT 
Flight Program: ISS 
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) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Flight Assignment/Project Notes: ISS

NOTE: end date changed to 9/30/2008, from 9/01/2010, per PI (10/08)

In flight development phase (data collection has begun)

Task Description: Following space flight, astronauts experience disturbances in balance and walking control during the postflight readaptation period due in part to changes in the way the central nervous system processes sensory information as a result of exposure to microgravity. These changes can pose risks to crew safety and mission objectives if nominal or emergency vehicle egress is required immediately following space flight. At present, no operational countermeasure is available to mitigate these risks by facilitating rapid sensorimotor re-adaptation to gravitational environments. Therefore, the goal of this study is to develop an in-flight treadmill training program that facilitates recovery of locomotor function after space flight. The proposed training program is based on the concept of adaptive generalization. During this type of training the subject gains experience producing the appropriate adaptive behavior under a variety of sensory conditions and balance challenges. As a result of this training a subject learns to solve a class of balance and walking problems, rather than producing a single solution to one problem. Therefore, the subject gains the ability to "learn to learn" under a variety of conditions that challenge the balance and walking control systems. This study will develop an in-flight countermeasure built around the ISS treadmill exercise activities. By manipulating the sensory conditions of exercise (by varying visual flow patterns during walking) and modifying the task constraints (reading, head movements) this training regimen will systematically and repeatedly promote adaptive change in walking performance improving the ability of the astronaut to adapt to a novel gravity environment. It is anticipated that this training regimen will facilitate neural adaptation to planetary environments after space flight.

The Mobility protocol is performed by two sets of ISS subjects comprising Control and Experimental groups. All participating subjects (Control and Experimental) perform two tests of locomotor performance both pre and postflight: the Integrated Treadmill Locomotion Test and the Functional Mobility Test. The Experimental Group will also perform the in-flight training protocol throughout the increment and an inflight test of Dynamic Visual Acuity. Comparisons will then be made between recovery rates in the Control vs. Experimental groups.

Operational Protocols:

Pre and Postflight Testing

Locomotor function in both Control and Experimental groups will be assessed before and after space flight using two tests of gait function. The Integrated Treadmill Locomotion Test characterizes alterations in the integrated function of multiple sensorimotor sub-systems. This test calls for subjects to walk on a motorized treadmill while we assess changes in dynamic postural stability, head-trunk coordination, visual acuity and lower limb coordination strategies. The Functional Mobility Test provides a corresponding assessment of the functional and operational changes in locomotor function by testing subject’s ability to negotiate an obstacle course placed over a medium-density foam floor.

Test 1: Integrated Treadmill Locomotion Test

Subjects walk at 6.4 km/h on a motorized treadmill while performing a visual task consisting of identifying the position of the gap in the letter “C” that is presented centrally on a laptop computer positioned 4 meters in front at eye level. Each trial lasts approximately 30 seconds and is repeated four times.

Subjects also walk at 6.4 km/h on the treadmill while performing the same visual task described above but in this case with the letter “C” is presented centrally on a micro-display positioned 50 centimeters in front at eye level. Each of these trials last approximately 30 seconds and are repeated four times.

While subjects are walking on the treadmill and performing the visual task 3-dimensional full-body motion data are acquired using a video-based motion analysis system; gait cycle timing is measured using foot switches placed in the shoes and dynamic visual acuity is assessed by the visual task described above.

Test 2: Functional Mobility Test

Subjects walk at a preferred pace through an obstacle course set up on a base of 10 cm thick medium density foam. The foam provides an unstable surface that increases the challenge of the test. The 6.0 m X 4.0 m course consist of several pylons and obstacles made of foam. Subjects are instructed to walk through the course as fast as possible without touching any of the objects on the course. This task is repeated three times in the clockwise direction and 3 times in the counterclockwise direction. The dependent measures are time to complete the course and the number of obstacles touched or knocked down.

Variable Training Protocol (done on orbit during regular treadmill exercise): Using a visual display (Mobility Graphics Display, MGD) mounted at eye level over the ISS treadmill (TVIS, Treadmill with Vibration and Isolation System), crewmembers will see a visual representation of a virtual scene varying in yaw, pitch and roll motions. Subjects will be exposed to this stimulus during the 10 minute warm up and cool down period of their regular treadmill exercise period.

The goal of this study is to develop an in-flight treadmill training program designed to improve adaptability of balance and gait function facilitating recovery of functional mobility after long-duration space flight.

Following space flight, crewmembers have trouble standing and walking. The magnitude and duration of post-flight instability increases with longer exposure to microgravity and can pose a risk to crew safety and to mission objectives if normal or emergency exit is required immediately following space flight. Presently, no operational countermeasure is available to mitigate these balance and locomotor disturbances. This study proposes to develop a unified, multi-disciplinary countermeasure system designed to enhance post-flight adaptive locomotor function that can be easily integrated with the existing International Space Station (ISS) treadmill procedures, without requiring more commitment of valuable crew resources. If successful, this experiment will provide methods for impoving postflight functional mobility.

Research Impact/Earth Benefits: As people age on Earth, they sometimes experience instabilities in standing and walking. The development of unique walking and balance training procedures like the ones proposed in this study can be used to help prevent falling and injury in the elderly population. An associated study being conducted at the University of Texas Medical Branch, funded by the NASA Graduate Student Research Program, is currently investigating this issue.

Task Progress & Bibliography Information FY2006 
Task Progress: See FY2007 report.

Bibliography Type: Description: (Last Updated: 05/21/2021) 

Show Cumulative Bibliography Listing
 
 None in FY 2006
Project Title:  Promoting Sensorimotor Response Generalizability: A Countermeasure to Mitigate Locomotor Dysfunction After Long-Duration Spaceflight Reduce
Fiscal Year: FY 2005 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 05/01/2000  
End Date: 09/30/2008  
Task Last Updated: 11/22/2005 
Download report in PDF pdf
Principal Investigator/Affiliation:   Bloomberg, Jacob J. Ph.D. / NASA Johnson Space Center 
Address:  NASA Emeritus Scientist, Biomedical Research and Environmental Sciences Div 
2101 NASA Parkway, SK272 
Houston , TX 77058-3607 
Email: jacob.j.bloomberg@nasa.gov 
Phone: 281-483-0436  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Mulavara, Ajitkumar  Ph.D. Baylor College of Medicine, National Space Biomedical Research Institute 
Cohen, Helen  Ph.D. Baylor College of Medicine 
Project Information: Grant/Contract No. None 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: 98-HEDS-02 
Grant/Contract No.: None 
Project Type: FLIGHT 
Flight Program: ISS 
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) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Flight Assignment/Project Notes: ISS

In flight development phase (data collection has begun)

NOTE: end date changed to 9/30/2008, from 9/01/2010, per PI (10/08)

Task Description: Following space flight, astronauts experience disturbances in balance and walking control during the postflight readaptation period due in part to changes in the way the central nervous system processes sensory information as a result of exposure to microgravity. These changes can pose risks to crew safety and mission objectives if nominal or emergency vehicle egress is required immediately following space flight. At present, no operational countermeasure is available to mitigate these risks by facilitating rapid sensorimotor re-adaptation to gravitational environments. Therefore, the goal of this study is to develop an in-flight treadmill training program that facilitates recovery of locomotor function after space flight. The proposed training program is based on the concept of adaptive generalization. During this type of training the subject gains experience producing the appropriate adaptive behavior under a variety of sensory conditions and balance challenges. As a result of this training a subject learns to solve a class of balance and walking problems, rather than producing a single solution to one problem. Therefore, the subject gains the ability to "learn to learn" under a variety of conditions that challenge the balance and walking control systems. This study will develop an in-flight countermeasure built around the ISS treadmill exercise activities. By manipulating the sensory conditions of exercise (by varying visual flow patterns during walking) and modifying the task constraints (reading, head movements) this training regimen will systematically and repeatedly promote adaptive change in walking performance improving the ability of the astronaut to adapt to a novel gravity environment. It is anticipated that this training regimen will facilitate neural adaptation to planetary environments after space flight.

The Mobility protocol is performed by two sets of ISS subjects comprising Control and Experimental groups. All participating subjects (Control and Experimental) perform two tests of locomotor performance both pre and postflight: the Integrated Treadmill Locomotion Test and the Functional Mobility Test. The Experimental Group will also perform the in-flight training protocol throughout the increment and an inflight test of Dynamic Visual Acuity. Comparisons will then be made between recovery rates in the Control vs. Experimental groups.

Operational Protocols:

Pre and Postflight Testing

Locomotor function in both Control and Experimental groups will be assessed before and after space flight using two tests of gait function. The Integrated Treadmill Locomotion Test characterizes alterations in the integrated function of multiple sensorimotor sub-systems. This test calls for subjects to walk on a motorized treadmill while we assess changes in dynamic postural stability, head-trunk coordination, visual acuity and lower limb coordination strategies. The Functional Mobility Test provides a corresponding assessment of the functional and operational changes in locomotor function by testing subject’s ability to negotiate an obstacle course placed over a medium-density foam floor.

Test 1: Integrated Treadmill Locomotion Test

Subjects walk at 6.4 km/h on a motorized treadmill while performing a visual task consisting of identifying the position of the gap in the letter “C” that is presented centrally on a laptop computer positioned 4 meters in front at eye level. Each trial lasts approximately 30 seconds and is repeated four times.

Subjects also walk at 6.4 km/h on the treadmill while performing the same visual task described above but in this case with the letter “C” is presented centrally on a micro-display positioned 50 centimeters in front at eye level. Each of these trials last approximately 30 seconds and are repeated four times.

While subjects are walking on the treadmill and performing the visual task 3-dimensional full-body motion data are acquired using a video-based motion analysis system; gait cycle timing is measured using foot switches placed in the shoes and dynamic visual acuity is assessed by the visual task described above.

Test 2: Functional Mobility Test

Subjects walk at a preferred pace through an obstacle course set up on a base of 10 cm thick medium density foam. The foam provides an unstable surface that increases the challenge of the test. The 6.0 m X 4.0 m course consist of several pylons and obstacles made of foam. Subjects are instructed to walk through the course as fast as possible without touching any of the objects on the course. This task is repeated three times in the clockwise direction and 3 times in the counterclockwise direction. The dependent measures are time to complete the course and the number of obstacles touched or knocked down.

Variable Training Protocol (done on orbit during regular treadmill exercise): Using a visual display (Mobility Graphics Display, MGD) mounted at eye level over the ISS treadmill (TVIS, Treadmill with Vibration and Isolation System), crewmembers will see a visual representation of a virtual scene varying in yaw, pitch and roll motions. Subjects will be exposed to this stimulus during the 10 minute warm up and cool down period of their regular treadmill exercise period. The goal of this study is to develop an in-flight treadmill training program designed to improve adaptability of balance and gait function facilitating recovery of functional mobility after long-duration space flight. Following space flight, crewmembers have trouble standing and walking. The magnitude and duration of post-flight instability increases with longer exposure to microgravity and can pose a risk to crew safety and to mission objectives if normal or emergency exit is required immediately following space flight. Presently, no operational countermeasure is available to mitigate these balance and locomotor disturbances. This study proposes to develop a unified, multi-disciplinary countermeasure system designed to enhance post-flight adaptive locomotor function that can be easily integrated with the existing International Space Station (ISS) treadmill procedures, without requiring more commitment of valuable crew resources. If successful, this experiment will provide methods for impoving postflight functional mobility.

Research Impact/Earth Benefits: As people age on Earth, they sometimes experience instabilities in standing and walking. The development of unique walking and balance training procedures like the ones proposed in this study can be used to help prevent falling and injury in the elderly population. An associated study being conducted at the University of Texas Medical Branch, funded by the NASA Graduate Student Research Program, is currently investigating this issue.

Task Progress & Bibliography Information FY2005 
Task Progress: We have collected pre and postflight locomotion data from the Expeditions 5, 6 7, 8, 9, 10 and 11 crews who will serve as part of the control group for this study. We have collected preflight data for the Expeditions 12 crews. We are also currently developing the inflight visual display system (Mobility Graphics Display), Dynamic Visual Acuity Measurement System and associated software.

We have also developed a Joint Research Protocol with our colleagues from the Institute of Biomedical Problems, Moscow, Russia to integrate the experimental operations of the Russian study “Locomotion” with that of Mobility.

Bibliography Type: Description: (Last Updated: 05/21/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Bloomberg, J.J.;Mulavara A.P.; Cohen H.S.;Richards J.T.; Miller C.A.;Peters B.T.;Marshburn A.;Brady R.A "Patterns of recovery in locomotor function following long-duration spaceflight" Barany Society XXIII International Congress, Paris, France

none , Jul-2004

Abstracts for Journals and Proceedings Bloomberg J.J.;Mulavara A.P.;Peters, B.T.;Cohen H.S.;Richards, J.T.;Miller, C.A. Brady R, Warren L.E "Development of an inflight countermeasure to mitigate postflight gait dysfunction" NASA Bioastronautics Meeting, Galveston, TX

None , Jan-2005

Abstracts for Journals and Proceedings Bloomberg, J.J.;Mulavara A.P.;Peters, B.T.;Cohen H.S.;Richards J.T.; Miller C.A., Brady R, Warren L. ". Development of training programs to mitigate post space flight gait dysfunction" American College of Sports Medicine Annual Meeting, Nashville, TN

None , Jun-2005

Abstracts for Journals and Proceedings Buccello, R.R., Cromwell, R.L., Bloomberg, J.J "The effects of sensorimotor adaptation training on functional mobility in older adults" Gerontological Society of America's 58th Annual Scientific Meeting, Orlando, FLA

None , Nov-2005

Articles in Peer-reviewed Journals Richards JT, Mulavara AP, Bloomberg JJ. "Postural stability during treadmill locomotion as a function of the visual polarity and rotation of a three-dimensional virtual environment." Presence, 2004 Jun;13(3):371-84. http://dx.doi.org/10.1162/1054746041422299 , Jun-2004
Project Title:  Promoting Sensorimotor Response Generalizability: A Countermeasure to Mitigate Locomotor Dysfunction After Long-Duration Spaceflight Reduce
Fiscal Year: FY 2004 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 10/01/2000  
End Date: 10/01/2005  
Task Last Updated: 03/20/2006 
Download report in PDF pdf
Principal Investigator/Affiliation:   Bloomberg, Jacob J. Ph.D. / NASA Johnson Space Center 
Address:  NASA Emeritus Scientist, Biomedical Research and Environmental Sciences Div 
2101 NASA Parkway, SK272 
Houston , TX 77058-3607 
Email: jacob.j.bloomberg@nasa.gov 
Phone: 281-483-0436  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments:  
Project Information: Grant/Contract No. None 
Responsible Center: NASA JSC 
Grant Monitor: McCollum, Suzanne  
Center Contact: 281 483-7307 
suzanne.g.mccollum@nasa.gov 
Solicitation / Funding Source: 98-HEDS-02 
Grant/Contract No.: None 
Project Type: FLIGHT 
Flight Program: ISS 
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) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Flight Assignment/Project Notes: ISS

Task Description: Following spaceflight crewmembers experience locomotor dysfunction due to inflight adaptive alterations in sensorimotor function. These changes can pose a risk to crew safety if nominal or emergency vehicle egress is required immediately following long-duration spaceflight. At present, no operational countermeasure is available to mitigate postflight locomotor disturbances. Therefore, the goal of this study is to develop an inflight training regimen that facilitates the recovery of locomotor function after long-duration spaceflight.

The countermeasure we are proposing is based on the concept of variable practice. During this type of training the subject gains experience producing the appropriate adaptive motor behavior under a variety of sensory conditions and response constraints. We are developing this inflight countermeasure built around current ISS treadmill exercise activities. Crewmembers will conduct their nominal inflight treadmill exercise while being exposed to variations in visual flow patterns, body load and treadmill speed. These variations will challenge the postural and locomotor systems repeatedly, thereby promoting adaptive reorganization in locomotor behavior. As a result of this training a subject learns to solve a class of motor problems, rather than a specific motor solution to one problem, i.e., the subject learns response generalizability or the ability to "learn to learn" under a variety of environmental constraints. We anticipate that this training will accelerate recovery of postural and locomotor function during readaptation to gravitational environments following spaceflight. We anticipate that this training regimen will facilitate neural adaptation to unit (Earth) and partial (Mars) gravity after long-duration spaceflight.

Our specific aims are to (1) develop and validate procedures necessary to implement a sensorimotor variable practice treadmill-training regimen in a weightless environment. This will require both ground-based studies and testing on NASA's KC-135 aircraft during parabolic flight, and (2) determine if the proposed in-flight treadmill-training regimen facilitates recovery of locomotor function following long-duration spaceflight on the ISS. This will require pre and postflight testing of astronaut locomotor function.

Research Impact/Earth Benefits: This investigation is one component of an integrated program of neuroscience experiments being conducted at Johnson Space Center designed to examine microgravity-induced adaptive modification of spatial orientation and motion perception processes, gaze control mechanisms, and postural and locomotor control. This information is also used to design countermeasures against the deliteroius effects of spaceflight on sensorimotor function.

In addition to addressing crew health and safety, this research will also further our understanding of clinical gait syndromes. NASA and the National Institute of Aging (NIA) have entered into a collaborative agreement to pursue research topics of common interest. Both the elderly population and returning space travelers experience postural and gait instabilities. However, in the case of returning astronauts, observed adaptive changes are truly plastic as they resolve themselves following interaction with the terrestrial 1-G environment. Alternatively, in the elderly population, postural and gait instabilities may persist surpassing the ability of the CNS to adapt and compensate for dysfunction. However as we investigate adaptive changes associated with flight of longer duration, we may find changes are not so fully reversible. Understanding how the CNS adapts to change and exploring the limits and range of plastic modification, whether it is aging or lack of a gravity vector, is central to the NASA/NIA collaborative effort.

The development of unique research protocols like the ones that have been developed in this study can be used by clinicians to evaluate rehabilitation techniques for patients with balance and gait disorders. Development of this new technology can lead to the establishment of worldwide clinical vestibular testing norms that can be used in medical facilities. In addition, this research can lead to the formulation of new models of neural activity based on known pathways and substrates. These models can be used to make predictions about response properties and transfer effects of a variety of motor subsystems following exposure to microgravity or as a predictive tool in clinical conditions.

In addition, the data obtained in this study has lead to the development of second generation tests of locomotor stablity and sensorimotor function that will be used to evaluate the efficacy of countermeasures against the deleterious effects of long-duration spaceflight.

Task Progress & Bibliography Information FY2004 
Task Progress: No progress this reporting period.

Bibliography Type: Description: (Last Updated: 05/21/2021) 

Show Cumulative Bibliography Listing
 
 None in FY 2004