Physiological Factors Contributing to Postflight Changes in Functional Performance (Functional Task Test) - 05.13.15
The Physiological Factors Contributing to Postflight Changes in Functional Performance (Functional Task Test) payload tests crew members on an integrated suite of functional and physiological tests before and after long-duration space flight. The study identifies critical mission tasks that may be impacted, maps physiological changes to alterations in physical performance and aids in the design of countermeasures that specifically target the physiological systems responsible for impaired functional performance. Science Results for Everyone
Information Pending Experiment Details
Jacob J. Bloomberg, Ph.D., Johnson Space Center, Houston, TX, United States
Brian T. Peters, Ph.D., Wyle Laboratories, Houston, TX, United States
Ajitkumar P. Mulavara, Ph.D., Universities Space Research Association, Houston, TX, United States
Lori L. Ploutz-Snyder, Ph.D., Universities Space Research Association, Houston, TX, United States
Millard F. Reschke, Ph.D., Johnson Space Center, Houston, TX, United States
Alan H. Feiveson, Ph.D., Johnson Space Center, Houston, TX, United States
Michael B. Stenger, Ph.D, Wyle Science Technology and Engineering Group, Houston, TX, United States
Stuart M. C Lee, Ph.D., Wyle Science Technology and Engineering Group, Houston, TX, United States
Scott J. Wood, Ph.D., Azusa Pacific University, Azusa, CA, United States
Barry A. Spiering, Ph.D., Wyle Laboratories, Houston, TX, United States
Jeffrey Ryder, Ph.D., Universities Space Research Association, Houston, TX, United States
NASA Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
Space Exploration, Earth Benefits, Scientific Discovery
ISS Expedition Duration
October 2009 - Ongoing
Previous ISS Missions
Functional Task Test began operations during ISS Expedition 21/22. Landing site data was first collected following the return of 34 Soyuz (return of the ISS Expedition 35/36 crew).
- Exposure to space flight causes adaptations in multiple physiological systems including changes in sensorimotor, cardiovascular, and sensorimotor systems. These changes may affect a crew member’s ability to perform critical mission tasks immediately after landing on a planetary surface. The overall goal of this project is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance.
- To achieve this goal this study uses an interdisciplinary testing protocol that evaluates both astronaut functional performance and related physiological changes. Functional tests include ladder climbing, hatch opening, jump down, manual manipulation of objects and tool use, seat egress and obstacle avoidance, recovery from a fall and object translation tasks. Physiological measures include assessments of postural and gait control, dynamic visual acuity, fine motor control, plasma volume, orthostatic intolerance, upper- and lower-body muscle strength, power, endurance, control, and neuromuscular drive. Crew members perform this integrated test protocol before and after long-duration (ISS) space flight. Data are collected during three sessions before flight, and 1, 6 and 30 days after landing. For some subjects, a subset of the protocol is collected on R+0 at the landing site in Kazakhstan with possible repetition of the tests during a refueling stop on the way to JSC, at JSC Astronaut Crew Quarters, and at R+60.
- The information obtained from this study will be used to design countermeasures that specifically target the physiological systems most responsible for the altered functional performance associated with space flight.
ISS Science Challenge Student Reflection
ISS Science Challenge Selected Project
This project really interested me from the start. In microgravity, the human body is affected physiologically, and this inhibits our abilities to perform certain tasks. But what tasks? And how are we inhibited? Thus, this experiment tests how and what functions are affected by microgravity. However, the experiment is still ongoing, but the results will be intriguing. When it's finished, it'd be interesting to see what scientists come up with to help us adapt to microgravity or how they change certain tasks on the ISS to better suit our bodies. -- Melody
I chose this because I thought the topic was interesting since it has to do with technology. It was also listed to have results in the chart, so I thought it would be nice to analyze the results. Although it didn't have results to analyze, I still kept the topic because I liked how it had pictures and showed the different machines tested various physiological functions. I learned about what functions were affected by space flight and how NASA intends to reduce the damage. -- Solana
-Solana, Grade 10 and Melody, Grade 12, Princeton High School, Princeton, New Jersey
Crew members experience alterations in multiple physiological systems due to exposure to the microgravity conditions of space flight. These physiological changes include sensorimotor disturbances, cardiovascular deconditioning and loss of muscle mass and strength. These changes lead to disruption in the ability to ambulate and perform functional tasks during the initial reintroduction to a gravitational environment following a prolonged transit and cause significant impairments in performance of operational tasks immediately following landing on a planetary surface. To date, changes in functional performance have not been systematically studied or correlated with physiological changes. To understand how changes in physiological function impact functional performance, an interdisciplinary testing regimen has been developed that systematically evaluates both astronaut postflight functional performance and related physiological changes.
The Physiological Factors Contributing to Postflight Changes in Functional Performance (Functional Task Test) study identifies the key underlying physiological factors that contribute to changes in performance of a set of functional tasks that are representative of critical mission tasks for planetary operations. Crew members test on an integrated suite of functional and interdisciplinary physiological tests before and after short- and long-duration space flight.
Using this strategy, Functional Task Test identifies critical mission tasks that are impacted by alterations in physiological responses, maps physiological changes to alterations in functional performance and designs and implements countermeasures that specifically target the physiological systems responsible for impaired functional performance.
To achieve the experimental goals a basic set of seven functional tests (Functional Task Tests) and a corresponding set of physiological measures were developed that specifically target the sensorimotor, cardiovascular and muscle changes associated with exposure to space flight. Physiological measures include: assessments of vestibular function, dynamic visual acuity, fine motor control, postural and locomotor stability, plasma volume, orthostatic (pertaining to an upright standing posture) intolerance, upper and lower body muscle strength, power, fatigue, control and neuromuscular drive.
Types of Functional Task Tests:
- Seat Egress and Walk: This test measures the ability to rise from a seated position (with seat upright and seat positioned with back to the floor) and walk while avoiding obstacles. Upon completion of the obstacle course, subjects attempt to walk 10 steps on the floor with the eyes closed, arms and hands folded across the chest, while placing the feet in the traditional tandem heel-to-toe position for each step.
- Recovery from Fall/Stand: For this test, subjects lie on a foam mat with their face down and then stand up as quickly as possible when a tone sounds. After standing up, subjects then perform the Stand Test by taking a step onto the solid floor and maintaining a quiet standing position for 3 minutes.
- Rock Translation: To simulate the task requirement of carrying objects, subjects pick up one of 3 weights (6, 10 and 20 pounds) that have a handle grip, and carry the weight a distance of 8 feet proceeded by placing it in a receptacle positioned 20 inches above the floor. This procedure repeats until all 3 weights have been individually transferred to the receptacle. The subject then returns each weight one-by-one to its original location 8 feet away from the receptacle.
- Torque Generation: A wheel attachment affixes to a PrimusRS system is used to simulate a hatch-opening task. Subjects stand on the floor while performing the hatch-opening task under both isometric and isotonic conditions. Subjects apply a torque to a wheel assembly under two conditions: a) Wheel Fixed--subject applies peak torque, and b) Wheel Free--subject moves wheel with constant resistance (50% of preflight peak) for 20 seconds.
- Ladder Climb: Crew members perform ladder climbing soon after landing on a planetary surface. To gain a better understanding of ladder climbing ability, subjects climb a passive treadmill ladder at a self-generated pace until they complete 40 rungs.
- Construction Activity Board: To assess changes in the ability to perform manual assembly and repair tasks, each subject completes a standard EVA training task. While standing, subjects perform a variety of standard construction and assembly tasks including connecting hoses to receptacles and mating a series of electrical connectors to the appropriate receptacles. Subjects also use a cordless power tool to tighten bolts on a handle assembly.
- Jump Down: Crew members are required to jump down from landing vehicles, habitats, and on uneven terrain during exploratory EVAs. During this test, subjects use a 2-footed hop to jump from a height of 30 cm and land on a force plate to measure the peak vertical impact force and postural stability on landing. Lower limb muscle activity in this test is measured using surface electromyography.
Types of Physiological Tests:
- Plasma Volume: Plasma volume is measured to determine changes in volume caused by space flight. This is measured through a cycle of quiet rest, 100% oxygen rebreathing, and carbon monoxide rebreathing with blood draws during carbon monoxide rebreathing.
- Fine Motor Control: To assess changes in fine motor control, this test uses the Grooved Pegboard Test that is a widely used test for neurological and vocational assessment of fine motor control. It is a manual dexterity test consisting of a 5x5 matrix of randomly oriented slotted keyholes with corresponding pegs that rest in a storage dish at the lower half of the board. Subjects complete the test as quickly and accurately as they can.
- Dynamic Posturography: Changes in the vestibular contributions to balance control are evaluated using a computerized dynamic posturography system. Trials are performed with eyes closed, on a sway-referenced base with the head erect and while subjects perform dynamic head tilts (forward, backward, or actively moving at 0.33 Hz paced by an audible tone).
- Treadmill Locomotion: This test simultaneously assesses changes in locomotor stability, head movement control and dynamic visual acuity. Subjects walk at 6.4 km/h for 90 seconds on a motorized treadmill while performing a Dynamic Visual Acuity (DVA) test consisting of Landolt C optotypes (standardized symbols used when testing eyesight) of various sizes being presented on a laptop screen placed 4 meters in front of the subject at eye level. Optotypes are oriented such that the opening of the C is pointed in one of four directions; up, down, left or right. By comparing the resulting visual acuity thresholds to the thresholds determined while the subject is stationery (i.e. sitting), the visual acuity decrement associated with head and body motion is assessed.
- Muscle Performance: Muscle Performance tests include; isometric strength, isometric force control, isotonic power endurance, and neuromuscular drive assessments. The primary purpose of these tests is to determine the contribution of muscle performance changes to alterations in FTT outcomes. Lower body measures for the isometric strength and isotonic power assessments are conducted using an inclined leg press device specifically instrumented for these purposes. Lower body measures for the isometric force control and neuromuscular drive are also assessed. Lower body measures will be conducted bilaterally. Upper body measures are performed bilaterally using a bench press with a braking system.
- Testing of crew responses following the long-duration flights typically does not begin until a minimum of 24 hours have elapsed between landing and the beginning of the testing. The R+0 testing using a subset of the FTT tests was designed to characterize balance, gait and cardiovascular disturbances as soon as possible (within 2 hours) after return at the Soyuz landing site when performance deficits are most profound and have greatest operational impact in terms of vehicle control and emergency egress. A clear identification of impairments and assessment of their extent at this time point is critical for addressing both vehicle control and egress risks for exploration class missions.
(1) Sit-to-Stand Test: crew member is asked to rise from a seated position (without assistance) to a standing position. Once standing, the crew member remains standing for up to 10 seconds then returns to the seated position.
(2) Recovery from Fall Test: crew member begins in the prone position on the ground and then stands for 3 minutes while cardiovascular parameters are measured and postural ataxia data are acquired.
(3) Tandem Walk Test: to determine changes in dynamic postural stability crew members are asked to attempt to walk placing the feet in the heel-to-toe position with arms and hands folded across the chest with eyes closed for up to 10 steps.
Video, cardiovascular parameters (heart rate and blood pressure), data from body worn inertial sensors and severity of postflight motion sickness are acquired for analysis.^ back to top
Information obtained from this study aids in the design of targeted countermeasures that mitigate physiological changes that impact operationally oriented functional performance.
A better understanding of the physiological factors that influence functional performance aids in defining more effective rehabilitation interventions in clinical populations. For example in the elderly population, activities of daily living are often impaired by multiple physiological causes. The information obtained from this study will aid in the design of clinical interventions and rehabilitation programs that can target specific systems responsible for decline in functional performance.
Thirteen subjects are requested to perform the preflight and postflight baseline data collection for Functional Task Test. Additionally, some subjects in Increments 38 to 43 will perform the FTT with Pilot Field Test (Bridge) protocol and data will be collected before and after the yearlong mission of the US crew member launching on 42S.
This investigation only requires baseline data collection (BDC) both preflight and postflight. No inflight testing will occur.
On-going data collection continues to improve the statistical power required to map changes in functional task performance to alterations in physiological systems. The information obtained from this study will be used to design and implement countermeasures that specifically target the physiological systems most responsible for the altered functional performance associated with space flight.^ back to top
Miller CA, Peters BT, Kofman I, Phillips TR, Batson C, Cerisano JM, Fisher E, Mulavara AP, Feiveson AH, Reschke MF, Bloomberg JJ. A comparison of tandem walk performance between bed rest subjects and astronauts. 39th Annual Meeting of the American Society of Biomechanics, Columbus OH; 2015 August 5-8 3 pp.
Miller CM, Peters BT, Kofman I, Brady R, Phillips TR, Batson C, Mulavara AP, Feiveson AH, Reschke MF, Bloomberg JJ. A comparison of torso stability between bed rest subjects and astronauts during tandem walk:Preliminary findings. 37th American Society of Biomechanics, Omaha, NE; 2013 September 4-7 2 pp.
Arzeno NM, Stenger MB, Bloomberg JJ, Platts SH. Spaceflight-induced cardiovascular changes and recovery during NASA's Functional Task Test. Acta Astronautica. 2013 November; 92(1): 10-14. DOI: 10.1016/j.actaastro.2012.05.023.
Ground Based Results Publications
NASA Image: jsc2008e156468 - Subject demonstrating the Seat Egress and Walk Test at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc20008e156463 - Subject demonstrating the Ladder Climb Test at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc2008e156464 - Subject demonstrating the Rock Translation Test at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc2008e156462 - Subject demonstrating the Torque Generation Test at Johnson Space Flight Center, Houston, TX.
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NASA Image jsc2008e156471 - Subject demonstrating the Construction Activity Board Test at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc2008e156475 - Subject participating in the Fine Motor Control Test at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc2008e156469 - Subject participating in the Treadmill Locomotion Test at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc2008e156477- Subject participating in the Muscle Performance Tests at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc2008e156479 - Subject participating in the Muscle Performance Tests at Johnson Space Flight Center, Houston, TX.
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NASA Image: jsc2008e156460 - Subject participating in the Plasma Volume Test at Johnson Space Flight Center, Houston, TX.
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