RMP-MSK-004 Back pain in flight: symptom tracking with red-flag escalation (no drug, position or exercise advice)

1 · Identity and scope

When a crewmember reports back or neck pain in flight, the robot runs structured check-ins: red-flag questions first (bladder, saddle-area feeling, bowel, both legs, arms and hands with neck pain, sudden tearing pain, fever, injury), then pain rating, where it is, where it spreads and what changes it. It logs the answers word for word and sends them to the flight surgeon; any red-flag answer goes to the CMO and flight surgeon at once. It can show a care plan a human has already entered, word for word, but gives no drug, position or exercise advice and never touches the back.

Why this protocol was chosen. In a NASA records review, 52% of astronauts (382 of 728) had space adaptation back pain, mostly mild (86%), usually in the first days of flight; it is thought to come from the spine straightening and lengthening without gravity. Because it is so common, the rare serious causes can be missed. Disc herniation was 4.3 times more common in US astronauts than in matched controls, relatively more often in the neck, with evidence that the risk is increased immediately after flight (the study looked at diagnoses after flight, not during it). On Earth, suspected cauda equina syndrome (pressure on the nerve roots at the base of the spine) needs emergency assessment, and no single symptom rules it in or out. Neck disc problems can press on the spinal cord, and sudden tearing back pain can be an aortic emergency, so both are asked about too. Asking the same red-flag questions every time makes a missed warning sign less likely.

Related: RMP-MSK-001 · RMP-MSK-002 · RMP-RENAL-001 · RMP-RENAL-002 · RMP-INF-001 · RMP-CARD-002 · RMP-EGR-003

2 · Roles

Medical authority

Flight surgeon (ground). Holds medical authority for every run.

Onboard lead

Crew medical officer (CMO), acting under delegated care; uses the pre-approved onboard checklist when there is no link.

Others

• Crewmember with pain: answers check-ins, can skip any question and can stop at any time
• Flight surgeon: reviews the log and sets the care plan

Commercial flights

On commercial flights, 'flight surgeon' and 'CMO' mean the operator's designated medical authority and trained onboard responder. If no trained responder is aboard, this protocol is not used. (NASA-STD-3001 requires two CMOs per vehicle for NASA programs [V1 3006]; FAA rules set no medical standards for spaceflight participants.) [14]

3 · Preconditions and consent

• PRE-1 A crewmember (the one with pain, or the CMO) started the log by command.human_start == trueV2 10174
• PRE-2 The crewmember is awake and answering; no fall, impact or crush injury (if there was, use RMP-MSK-001 or RMP-MSK-002).crew_responsive == true and injury == false
• PRE-3 Robot self-test passed.V2 10161
• PRE-4 Link status and current delay known.

Consent

The crewmember agrees by voice or touch; any question can be skipped. Questions about bladder, bowel and sexual function are asked privately, and the crewmember chooses who is present.

Emergency consent

Not applicable; the robot does not continue without the crewmember's answers. If the crewmember cannot answer, it calls the CMO.

Withdrawal

The crewmember can stop at any time; the robot logs where it stopped.

4 · Required sensor inputs

5–6 · Steps and decision points

Each step names who acts. Decision points sit after the step they follow and say who decides: Robot Crew Ground. Any stop rule in section 7 can interrupt any step.

1. S1RobotRung 2

   On a crewmember's command, open the log, tell the CMO, and send a "back pain log started" note to the flight surgeon (queued if the link is down).

   Done when: CMO acknowledges; note delivered or queued.

   V2 10174V1 6003

2. S2RobotRung 2

   Ask the red-flag questions first (privately for bladder, bowel and sexual function), and log the answers word for word.

   Done when: Each red-flag question answered or marked for the CMO to ask.

   D1DecisionRobot decides

   Is any red-flag answer "yes", or not answered?

   • Yes → Stop the routine questions. Apply the action listed for each matching red flag (URGENT alert, stop, or private flag) with the answer itself; on any URGENT flag the CMO assesses in person. A normal CMO examination does not cancel a "yes" answer; the flight surgeon decides. The robot does not say what it means.
   • Not answered → Ask the CMO to ask in person before the pain questions; never treated as "no".
   • All "no" → Continue to S3.
3. S3RobotRung 2

   Ask the pain questions: rating, place, spread, timing, and what makes it better or worse. Log answers word for word.

   Done when: Answers logged.

4. S4RobotRung 2

   On request, show the care plan the CMO or flight surgeon has entered for this crewmember, word for word, with who entered it and when. If there is none, say "No care plan entered; ask the CMO."

   Done when: Plan shown, or "no plan" shown.

5. S5RobotRung 2

   Send the answers to the flight surgeon, or queue them and show the CMO the onboard checklist page.

   Done when: Delivered or queued.

   V1 6003V1 7003

   D2DecisionGround decides

   What is the plan?

   • Link live → Flight surgeon decides; robot logs.
   • Link down or delay too long → The CMO decides under the pre-approved onboard checklist; the flight surgeon reviews the log at the next contact.
6. S6Crew

   The CMO assesses in person when asked or on any red flag. Any medicine is ordered by a human and fetched through RMP-PHARM-001.

   Done when: CMO decision logged.

7. S7Ground

   The flight surgeon (or the CMO under the onboard checklist when there is no link) sets the care plan and the check-in schedule; the robot logs them.

   Done when: Plan logged.

8. S8RobotRung 2

   Offer a check-in every <set by flight surgeon> hours, red-flag questions first every time, until the flight surgeon closes the log. At each scheduled time the robot prompts the crewmember on their own screen; it approaches only when the crewmember (or the CMO) accepts, and a prompt never starts the robot.

   Done when: Each prompt accepted, postponed or answered; log closed by a human.

   V2 10174

   D3DecisionRobot decides

   Is the pain rating rising, or is pain lasting beyond the time the flight surgeon set, or new after the first flight days?

   • Yes → Flag to the flight surgeon and CMO: not assumed to be space adaptation back pain.
   • No → Continue the schedule.

7 · Stop and escalate rules, red flags

Red flags

The robot reports the sign or value only, never what it means. Numeric thresholds are placeholders for the clinical lead.

8 · Safety limits

9 · Logs and audit

• LOG-1 Every input, robot action, decision (with who made it) and hand-off, time-stamped to the second.V2 10163V2 10164
• LOG-2 Mode changes and safety-limit events are announced to the operator as they happen and logged.V2 10162V2 10172
• LOG-3 Records are stored and sent as private medical data, encrypted, with access limited to the medical team.V1 6003V1 7003
• LOG-4 Results are kept in a permanent, retrievable format so the flight surgeon can see trends.V1 7001
• LOG-5 Every red-flag answer, with the time it was asked and when the alert was acknowledged, so missed or late escalations can be audited.

10 · Links to NASA-STD-3001

IDs as published in Volume 1 Revision C [10] and Volume 2 Revision F [11]. NASA-STD-3001 binds NASA programs; it is not a regulation for commercial flights. Its robot rules are general automation requirements, not medical-device rules.

11 · Validation

1. Simulation. Scripted check-ins with every red-flag answer, unanswered questions and rising pain, at station, Moon and Mars delays. Pass: Every red-flag answer alerts within <set by validation>; zero advice; zero plans shown that a human did not enter.
2. Earth analog. Analog crews (for example bed-rest or isolation studies) using the check-ins, reviewed by remote clinicians. Pass: Clinicians judge the logs usable; crew rate the private questions acceptable.
3. Flight use under flight surgeon supervision. Logging aid alongside private medical conferences in the first flight days. Pass: No safety events; no red flag missed when compared with the conference notes.

No stage has been run. Pass and fail criteria must be fixed in advance by the clinical lead and safety board.

12 · Human sign-off

Before any use

• Clinical lead for the specialty (sets every clinical threshold marked <set by clinical lead>)
• Flight surgeon, as medical authority
• Robotics and medical-device safety board
• Program approval for the mission

Each run

Started by a crewmember. The flight surgeon reviews the log at each private medical conference; red flags go to the CMO and flight surgeon at once.

Restart after a stop

Human only. After any emergency or protective stop, a crewmember must restart the robot; the robot never restarts itself.

None of these sign-offs has happened. This is a Draft v0.4.

13 · Change control for learning

• Every change gets a new version number and a written reason; earlier versions are kept.
• Any change to steps, thresholds, limits or software that touches the patient repeats validation from the simulation stage before use.
• Software and learned-skill updates follow a pre-agreed change plan (what may change, how it is tested, how to roll back), modeled on the FDA predetermined change control plan approach.
• If a new version misbehaves, the robot rolls back to the last validated version and the event is reviewed by the flight surgeon and safety board.
• The robot never changes its own protocol, thresholds or limits.

Change-plan model: FDA guidance [13].

Loss of signal and Mars delay

Live link

Low Earth orbit: red flags reach the flight surgeon within minutes; routine logs are reviewed at the private medical conference.

Loss of signal

• Only the robot pauses; crew care never waits for the link or the robot.
• The robot pauses any movement and tells the CMO; on the CMO's confirmation it keeps running check-ins and logging offline.
• Red-flag answers go to the CMO at once; the CMO decides under the pre-approved onboard checklist.
• At the next contact the robot sends one package: answers, alerts and decisions.

Mars-class delay

• Replies may take up to about 21-23 minutes each way, with blackouts of about 2-3 weeks, so the CMO acts on red flags onboard.
• Red flags, the check-in schedule and the onboard plan for suspected nerve-root compression are set before flight.

[12]

Sources

1. Kerstman EL, Scheuring RA, Barnes MG, DeKorse TB, Saile LG. Space adaptation back pain: a retrospective study. Aviat Space Environ Med. 2012;83(1):2-7. PMID 22272509. doi:10.3357/asem.2876.2012 Supports: Space adaptation back pain in 52% of astronauts (382/728); mild in 86%, moderate in 11%, severe in 3% of those affected; fetal positioning (91%) and analgesic medicines and exercise (85% each) were the most effective treatments; usually mild and self-limited, but moderate or severe pain that does not respond carries a risk of functional impairment and mission impact.
2. Johnston SL, Campbell MR, Scheuring R, Feiveson AH. Risk of herniated nucleus pulposus among U.S. astronauts. Aviat Space Environ Med. 2010;81(6):566-574. PMID 20540448. doi:10.3357/asem.2427.2010 Supports: In-flight back pain is presumably due to elongation of the spine; disc herniation was 4.3 times more common in US astronauts (321) than matched controls (983), relatively more often in the neck (18 of 44 astronaut herniations, against 3 of 35 in controls), with evidence that the risk is increased immediately after spaceflight. Used here for the neck red flag; no guideline listing spinal-cord (myelopathy) red flags was verified for this draft, so that wording is a clinical judgment.
3. NASA OCHMO. Space Adaptation Sickness (SAS) and Space Readaptation Syndrome. Medical Technical Brief OCHMO-MTB-004 Rev A (Sept 25, 2025). www.nasa.gov/wp-content/uploads/2025/09/ochmo-mtb-004-space-… Supports: Space adaptation back pain occurs in 52% of space travelers in the first 2-5 days of flight; microgravity reduces the usual curve of the back, causing it to straighten. Urinary retention can occur in the first few days of flight.
4. NHS England Getting It Right First Time (GIRFT). Spinal Surgery: National Suspected Cauda Equina Syndrome (CES) Pathway (February 2023). Also hosted by an NHS trust: https://www.gloshospitals.nhs.uk/media/documents/GIRFT_CES_Guidelines_2023_EJRRVj5.pdf (the copy that was read; the GIRFT-hosted copy could not be opened by automated retrieval). gettingitrightfirsttime.co.uk/wp-content/uploads/2023/02/Nat… Supports: Emergency referral for back or leg pain with recent onset of: difficulty starting to pass urine or impaired sensation of urine flow; altered perianal, perineal or genital (saddle) sensation; severe or progressive weakness of both legs; loss of the feeling of rectal fullness; or sexual dysfunction. Sudden pain down both legs, or one-leg pain that spreads to both, is a warning sign. No single symptom has good diagnostic accuracy, and negative physical tests do not rule out cauda equina syndrome if the symptoms are present; bladder scans should not be used in isolation or as a discriminator.
5. National Institute for Health and Care Excellence. Low back pain and sciatica in over 16s: assessment and management. NICE guideline NG59 (2016, last updated July 29, 2026). www.nice.org.uk/guidance/ng59/chapter/Recommendations Supports: Think about alternative diagnoses, particularly with new or changed symptoms, and exclude specific causes of low back pain such as cancer, infection, trauma or inflammatory disease.
6. Gulati M, Levy PD, Mukherjee D, et al. 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain. Circulation. 2021;144(22):e368-e454. PMID 34709879. doi:10.1161/CIR.0000000000001029 Supports: Sudden onset of ripping chest pain (with radiation to the upper or lower back) is suspicious of an acute aortic syndrome.
7. NASA Human Research Program. Evidence Report: Risk of Renal Stone Formation (2024). humanresearchroadmap.nasa.gov/evidence/other/2024%20Renal%20… Supports: The increased risk of renal stone formation occurs rapidly during spaceflight and continues throughout the mission; stones can cause renal colic or severe flank pain, blood in the urine, infection or sepsis; there have been no symptomatic kidney stones in flight to date in US crewmembers on the ISS.
8. NASA Human Research Program. Evidence Report: Risk of Adverse Health Outcomes and Decrements in Performance due to In-Flight Medical Conditions (2017). humanresearchroadmap.nasa.gov/evidence/reports/Medical.pdf Supports: Table 2: 382 space adaptation back pain events among US astronauts (Shuttle, Mir and ISS through 2006); Table 1: 1.99 back pain events per person-year on the ISS.
9. NASA OCHMO. Medical Operations. Technical Brief OCHMO-TB-044 (2025). www.nasa.gov/wp-content/uploads/2025/08/ochmo-tb-044-medical… Supports: The crew surgeon keeps medical authority when care is delegated; crew medical officers train on the JSC 48522 medical checklist.
10. NASA. NASA-STD-3001, Space Flight Human-System Standard, Volume 1: Crew Health, Revision C (2023). www.nasa.gov/wp-content/uploads/2023/11/nasa-std-3001-vol-1-… Supports: Requirement IDs beginning V1.
11. NASA. NASA-STD-3001, Volume 2: Human Factors, Habitability, and Environmental Health (Rev F, 2026), including Section 10.6 Automated and Robotic Systems. standards.nasa.gov/standard/NASA/NASA-STD-3001_VOL_2 Supports: Requirement IDs beginning V2.
12. NASA. Mars communications disruption and delay (fact sheet, 2023 Moon to Mars Architecture Concept Review). www.nasa.gov/wp-content/uploads/2024/01/mars-communications-… Supports: One-way Earth-Mars delay up to about 21-23 minutes, plus blackouts of about 2-3 weeks near solar conjunction.
13. U.S. Food and Drug Administration. Marketing submission recommendations for a predetermined change control plan for artificial intelligence-enabled device software functions (guidance). www.fda.gov/regulatory-information/search-fda-guidance-docum… Supports: A model for planning, validating and rolling back software updates.
14. U.S. Code of Federal Regulations, Title 14, Part 460: Human space flight requirements. www.ecfr.gov/current/title-14/chapter-III/subchapter-C/part-… Supports: Federal rules for crew and spaceflight participants on licensed commercial flights; they set no medical standards for spaceflight participants.

Checked on 2026-10-20: links opened (HTTP 200 or publisher redirect), DOIs and PubMed IDs matched, NASA documents read in full text. The framework comes from Part 1.