Functional Task Test (FTT) A

Collaborative study between several labs at NASA-Johnson Space Center

Neuroscience LabJacob J. Bloomberg, Ph.D. (PI)Ajitkumar Mulavara, Ph.D.Brian T. Peters, Ph.D.Millard F. Reschke, Ph.D.Scott Wood, Ph.D.Emily Lawrence, M.S.Igor Koffman, B.S.

Exercise Physiology LabLori Ploutz-Snyder, Ph.D.Barry A. Spiering, Ph.D.

Cardiovascular LabSteven H. Platts, Ph.D.Michael B. Stenger, Ph.D.Stuart M.C. Lee, M.S.Natalia Arzeno, M.Eng.

Research StatisticianAlan H. Feiveson, Ph.D.

Exercise Countermeasure ProjectJeffrey Ryder, Ph.D.Yamil Garcia, M.S., ATC, CSCS

Muscle Research Lab ASCRDaniel L. Feeback, Ph.D. Mark E. Guilliams, M.A., CSCS

Background N QN,

After space flight there are changes in multiple physiologicalsystems:

• Cardiovascular function• Balance, gait and eye movement control• Muscular mass, strength and endurance

How do changes in physiological systems impact astronautfunctional performance?

Functional Task Test (FTT): interdisciplinary testing regimenhas been developed to evaluate astronaut postflightfunctional performance and related physiological changes.

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Objectives

• Develop a set of functional tasks that represent criticalmission tasks for the Constellation Program.

• Determine the ability to perform these tasks after spaceflight.

• Identify the key physiological factors that contribute tofunctional decrements.

• Use this information to develop targeted countermeasures.

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Why use ISS to Answer our Research a ^,^

Question?

Require an assessment of how multiple physiological systemsimpact functional performance after long-duration space flight.

Ground based models (e.g. bedrest) do not capture the entirecomplement of space flight related physiological changes thatimpact astronaut functional performance.

Require actual space flight to map linkages betweenphysiological changes and functional performance.

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Seat Egressand Walk

Ladder Climb

MapRock

TranslationRecovery from

Fall/Stand

W {^r

Torque GenerationConstruction

Activity

Functional Performance

Physiological Measures

Muscle• Strength• Power• Control• Neuromuscular Drive

Sensorim o tor s^'• Balance• Gait ^;To• Dynamic Visual Acuity• Fine Motor Control

Cardiovascular 7

• Plasma Volume

Jump Down

.^ Mapping to Critical Mission Tasks

Critical Mission RepresentativeTasks Identified by Functional Test

Constellation

Ingress/Egress Seat Egress and WalkVehicle/Habitat/CEV Jump Down

Ladder/Climb and Ladder ClimbDescend

Recovery from Recovery from Fall/StandFall/Near Fall

Lift and Carry Objects Rock Translation

Open/Close Hatch Torque Generation

Assembly, Construction ActivityConstruction and BoardRepair Activities

Body motion sensors onand trunk: kinematics

Holter monitor: EKG

Portapress: continuousblood pressure

TInstrumentation for Functional a^<^

Testing

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Functional Tests

1) Seat Egress and Walk Test:

Unbuckle a harness, get up from aseat and complete an obstaclecourse. Testing will occur with:a) seat upright.b) seat positioned with its back to thefloor.Tandem heel-to-toe walk test witheyes closed.

2) Recovery from Fall/Stand Test:Stand up as quickly as possible andthen step on a solid floor and remainstanding for 3 minutes.

g

Functional Tests (cont.)

3) Ladder Climb:Climb 40 rungs on a passive treadmill ladder at aself-generated pace.

4) Torque Generation:Apply torque to a wheel assembly while standing:a) Wheel fixed: Apply peak torque.b) Wheel is free to move with constant resistance.

Subject turns wheel as many times in 20 s. (50%preflight peak).

5) Rock Translation:Transfer three weights (6, 10, 20 lbs) with handles,one at a time, a distance of 8 feet and place in areceptacle and then transfer the weights back to theinitial receptacle.

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Functional Tests (cont.

6) Construction Activity Board:Connect hoses to receptacles andmate a series of electricalconnectors to the appropriatereceptacles. Remove and replacebolts on a handle assembly using acordless power tool.

7) Jump Down:Jump down from a platform with aheight of 30 cm onto a force plate.Surface electromyographicelectrodes will be placed on theleg to assess neuromuscularactivation patterns.

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Physiological Tests

Sensorimotor Tests

1) Postural Stability: Maintain balance onsway-referenced support surface witheyes closed. This test will be performedwith and without head movements.

2) Fine Motor Control: Place 25 keyedpegs into their corresponding slots whileseated.

3) Gait Control/Dynamic Visual Acuity:Walk at 6.4 km/h for 90 s on a treadmillwhile performing a dynamic visual acuity(DVA) test consisting of identifying gapsin the letter C presented on a computerscreen. 11

Physiological Tests (cont.)Cardiovascular Test

4) Plasma Volume

Determined using a carbon monoxide rebreathingmethod.

Safe and reliable method; used by the JSCCardiovascular Laboratory since 1992.

Methods

1) Initial blood sample of 3 ml drawn.2) Breathe 100% oxygen on a closed breathing

circuit for 2 minutes.3) Sixty ml of carbon monoxide injected into the

breathing circuit.4) Rebreathe this mixture for 10 minutes.5) Second blood sample of 3 ml drawn.

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Physiological Tests (cont.

Muscle Performance Tests

5) Leg Press: Lower Body Force,Power and Endurance

a) Maximum Isometric Force: Subjectpushes against a fixed force plate.

b) Power/Endurance: Subject pushesa weight away as fast as possible(40% max force, 21 repetitions,ballistic, concentric only, magneticbrake catches weight).

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Physiological Tests (cont.

Muscle Performance Tests

6) Knee Extension: Lower Body ForceControl and Neuromuscular Drive

a) Force Control: Subject matches legforce with a reference force displayed oncomputer screen during isometric legextension (5% max force).

b) Neuromuscular Drive: Twitchinterpolation method; electrical musclestimulus is provided to thigh muscleduring isometric leg extension.

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Physiological Tests (cont.)Muscle Performance Tests

7) Bench Press: Upper Body Force,Power and Endurance

a) Maximal Isometric Force: Subjectpushes against fixed bar.

b) Power/Endurance: Subject pushes aweight away as fast as possible (30%max force, 21 repetitions, ballistic,concentric only, magnetic brakecatches weight).

c) Force Control: Match isometric armforce with a reference force displayedon a computer screen (5% maximalforce). 15

Testin g Schedule

Preflight Postflight

Shuttle: R+0, R+1, R+6, R+30

L-180, L-60, L-30ISS: R+1, R+6, R+30

Current Crew Participation:

Shuttle Flights: STS-128, 129, 131

ISS Flights: 22/23, 23/2416

Earth Benefits

This research has direct application in the design of clinicalinterventions and rehabilitation programs for patientpopulations that experience alterations in multiplephysiological systems leading to decline in functionalperformance (e.g. the elderly).

Interventions can be tuned to target the specific physiologicalsystems responsible for changes in functional performance.

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