The pain rule you were taught was never a rule

1. The rule of thumb, and where it actually comes from

The model has a name. It is called the Pain-Monitoring Model, and the cleanest modern statement of it appears in the background section of a 2021 pilot randomised trial on pain-guided activity modification during treatment for patellar tendinopathy, by Sprague and colleagues at the University of Delaware. That paper sets out the model in two parts: a ceiling on how much pain is acceptable during or immediately after activity, rated on the numeric pain rating scale, and a condition that pain ratings return to their pre-activity level by the following morning.

The number in that first part is the one the gym repeats. The second part usually falls off in transit, and the provenance falls off before that.

Here is the provenance, in the 2021 paper's own words: the model was "[o]riginally described by Thomeé et al. for use in patellofemoral pain." Patellofemoral pain is not Achilles tendinopathy. It is not patellar tendinopathy either, despite the adjacent anatomy. It is a distinct clinical problem, and the model's numbers were set there first, for that. The 1997 Thomeé paper itself was not obtained for this article, so nothing is claimed about its cohort, its size or its own findings; the attribution is reported as Sprague and colleagues state it, and no further.

The route from there to the number's fame runs through a single trial. In 2007, Silbernagel, Thomeé, Eriksson and Karlsson published a randomised controlled study in the American Journal of Sports Medicine on continued sports activity, using a pain-monitoring model, during rehabilitation in patients with Achilles tendinopathy. That trial is where most people's confidence comes from, whether or not they know it. It enrolled 38 patients.

Thirty-eight patients, one tendon, one diagnosis, a supervised twelve-month rehabilitation programme, with the monitoring instruction given to people a clinician had already examined. That is the foundation of the rule your training partner recites about a rib.

Two further facts about the number matter more than its value. The first is that in the Achilles trial the ceiling never travelled alone: the instruction also held that Achilles pain and stiffness were not allowed to increase from week to week. A ceiling plus a trend rule plus a clinician is a different object from a ceiling. The second is what the current expert literature says about the figure's status, which is the subject of the next section.

2. A different tendon gets a different number

If the threshold were a property of human tissue, it would be the same number everywhere. It is not.

A 2025 clinical commentary in the International Journal of Sports Physical Therapy, on individualised physiotherapy for proximal hamstring tendinopathy, describes a staged loading programme with its own pain ceiling during loading — lower than the familiar one — which is then lowered again at the stage involving energy storage and release work, "as these exercises are thought to be more provocative in tendinopathy and the risk of a flare up of pain is greater." Same body, same broad category of problem, different tendon, different numbers, and the numbers move within a single programme depending on what the exercise does.

That commentary also carries its own twenty-four-hour condition, expressed as an acceptable small increase in pain with repeatable tasks within a day of the session, and a larger increase persisting beyond that day as the trigger for modifying the prescribed exercise. Note what that is: a trigger for a clinician to change a prescription, inside a programme the clinician wrote. It is not a self-test.

So there is no such thing as "the twenty-four-hour rule." There are at least two twenty-four-hour conditions in this literature, attached to different tendons, phrased differently, doing different jobs. The patellar and Achilles version asks for a return to the pre-activity level by the following morning. The proximal hamstring version tolerates a small next-day increase and modifies the exercise when a larger one persists. Presenting either as the rule would be inventing a consensus that the primary sources do not contain.

The most honest line in any of these papers is the one that describes the common figure as the most commonly used threshold across tendinopathy protocols. That is an anthropological claim about what clinicians do, not an empirical claim that the figure separates safe loading from harmful loading. The experts using the number are telling you it is convention.

A systematic review of return-to-sport definitions in midportion Achilles tendinopathy makes the disorder in the field explicit. Across the protocols it examined, the criteria were not standardised at all: one commentary required minimal-to-no pain with all activities of daily living before any running or jumping was permitted; others allowed running if it could be performed with only mild discomfort and no pain; others reported no criteria whatsoever. This is a field that has not agreed with itself about a single tendon in a single location. It has certainly not agreed about your shin.

3. What the Achilles trial found, and what it did not

The Silbernagel trial deserves a careful reading, because it is genuinely good news and it is routinely overstated.

Thirty-eight patients with Achilles tendinopathy were randomised, nineteen to each arm. The exercise group continued running and jumping under the pain-monitoring model. The control group stopped such activity for the first six weeks. Both groups improved significantly, and there was no significant difference in the rate of improvement between them. The authors' conclusion is worth reading exactly as written: "No negative effects could be demonstrated from continuing Achilles tendon-loading activity, such as running and jumping, with the use of a pain-monitoring model, during treatment."

That sentence is carefully built, and every part of it is load-bearing. No negative effects could be demonstrated is not there are no negative effects; in a trial with nineteen patients per arm, a great many real effects could fail to be demonstrated. Achilles tendon-loading activity is not any training. With the use of a pain-monitoring model is not at will. During treatment means during a supervised twelve-month rehabilitation programme for a diagnosed condition.

What the trial supports is a real and important claim: for a diagnosed midportion Achilles tendinopathy under supervision, the reflex of complete rest was not superior to continuing to load within a monitored range. What it does not support is any statement about a rib, a finger, a neck, a knee ligament, a bone, a nerve, a concussion, or any pain nobody has examined.

The sex split of that cohort is not stated in the fetched abstract, so nothing is claimed about how the finding distributes between men and women.

4. Hurt is not the same measurement as harm

There is a broader body of evidence on whether therapeutic exercise is allowed to be painful, and it points the same way without extending any further than it should.

A 2017 systematic review and meta-analysis in the British Journal of Sports Medicine asked whether exercises should be painful in the management of chronic musculoskeletal pain. It pooled nine papers reporting seven trials with 385 participants. Protocols that permitted painful exercise showed a small short-term advantage — a standardised effect of −0.27, with a 95% confidence interval from −0.54 to −0.05, on moderate-quality evidence. At medium and long term there was no significant difference, and there was no difference for function or disability at any timepoint. The population is adults with chronic musculoskeletal pain of mixed diagnoses.

The authors' own summary is the right size for the finding: pain during therapeutic exercise for chronic musculoskeletal pain need not be a barrier to successful outcomes. Read that as permission to stop treating a painful rehabilitation exercise as proof that the rehabilitation is going wrong. Do not read it as evidence about undiagnosed pain in a training session, which the trials did not study.

The clinical commentaries in this area are direct about why the distinction is hard to hold. The same proximal hamstring paper notes that latent pain onset after completion of activity is common in tendinopathy and thought to indicate unhelpful loading, "although the underpinning mechanisms for this response are uncertain." Uncertain mechanisms are exactly the conditions under which a pain reading cannot be converted into a statement about tissue. The boxer case in section seven is the counterexample that closes the argument: a real fracture that imaging initially failed to show and that pain could not classify.

5. The injuries that are invisible to the method that counts them

Now the second argument, which is the one that changes how a camp should be read.

Most sports injury epidemiology counts injuries by time loss: an injury exists when an athlete misses training or competition. That definition is administratively clean and, for a torn knee in a scramble, entirely adequate. For the problems that accumulate, it is close to useless — because their defining characteristic is that the athlete keeps training.

In 2013, Clarsen, Myklebust and Bahr published a validation study in the British Journal of Sports Medicine of a new method built around that problem: the Oslo Sports Trauma Research Centre overuse injury questionnaire. It ran for 13 weeks across 313 athletes in five sports — cross-country skiing, floorball, handball, road cycling and volleyball. Every athlete completed a questionnaire by email each week about problems in the knee, lower back and shoulder. Standard time-loss registration ran alongside it, in parallel, on the same athletes.

The questionnaire recorded 419 overuse problems in those three body areas over the three-month period, of which 142 were classified as substantial — meaning they led to moderate or severe reductions in sports performance or participation, or to time loss. Each week, an average of 39% of athletes reported having an overuse problem and 13% reported a substantial one.

Standard registration, over the same weeks, in the same athletes, in the same three body areas, recorded 40 overuse injuries, the majority of minimal or mild severity.

Those two counts are counts of different things, and the honest reading does not turn them into a percentage — 419 problems and 40 injuries do not share a unit, so no miss rate can be computed from them. What can be said is what the authors said: "Standard injury surveillance methods only capture a small percentage of the overuse problems affecting the athletes, largely because few problems led to time loss from training or competition." And, in the discussion: "Clearly, basing severity on time loss alone underestimates the true impact of overuse problems."

The cohort limits have to travel with those figures every time they are used. Five non-combat sports. Three body areas. Elite and sub-elite athletes in Norway. These are not fighter rates, they are not knee rates for grapplers, and they cannot be scaled into combat sports by any coefficient. What transfers is the structural insight, not the percentages: a counting method that waits for absence will not see problems that do not produce absence. That insight is developed further in the injuries that arrive without an incident, which looks at what the same measurement problem does across a fight camp.

6. "I have not missed a session" is not evidence

The practical consequence of section five is a sentence that should be retired from gym conversation.

I am fine, I have not missed a session. In a time-loss frame, that sentence is a clean bill of health, because in that frame health is defined as attendance. In the frame the surveillance work above establishes, it is an observation about attendance and nothing else. The 419 problems in the Norwegian cohort were, almost by definition, mostly being trained through. That is why they were invisible.

Fighters are worse placed than most athletes here, for reasons that have nothing to do with toughness. Camp compresses everything into a window with a fixed end date, which converts every complaint into a scheduling problem. Attendance is socially legible in a way that pain is not. And the sport does not run weekly symptom surveillance on anybody.

The only combat-sport datapoint located for this article that touches the question is indirect and weak, and it is worth exactly as much as its design allows. A 2017 survey published in Sports sent a 27-question instrument to 166 US Brazilian jiu-jitsu gyms. Respondents were mostly male, n = 121, average age 30.3. The commonest injury locations reported were hand and fingers, foot and toes, and arm and elbow. The interesting column is the split: the commonest medically diagnosed conditions were skin infections, knee and foot or toe injuries, while the commonest non-medically diagnosed complaints were hand and fingers, arm and elbow, foot and toes. That is a self-selected, recall-based survey with no exposure denominator and no overuse instrument, so it measures nothing about rates. What it is consistent with is a population carrying a quantity of long-running problems that no clinician has ever looked at.

The corrective is not a threshold. It is a record. What was trained, what was modified, what hurt and when it started, written down in a form a clinician can read in ninety seconds — which is the subject of tracking injuries in combat sports, and which is the only part of this an athlete can do alone without deciding anything medical.

7. The dangerous case: a niggle that is structural

Everything above concerns problems where continued loading, under supervision, may be reasonable. This section is about the case where the same presentation is something else, and the reason no article can hand you a rule.

Bone stress injury, in the words of a 2014 clinical commentary on management and prevention in long-distance runners, "represents the inability of bone to withstand repetitive loading, which results in structural fatigue and localized bone pain and tenderness. A BSI occurs along a pathology continuum that begins with a stress reaction, which can progress to a stress fracture and, ultimately, a complete bone fracture." The same paper flags the tendency of these injuries to recur. It labels its own level of evidence as expert commentary, not trial data, and it should be read that way.

Read the continuum sentence again with a fighter in mind. The early end of that continuum produces localised pain and tenderness under load, and stops hurting with rest. That description also fits a great many things that are not bone. The difference between them is not available to the athlete, the coach or the article.

What the prospective evidence adds is the consequence of finding it late. Nattiv and colleagues followed 211 collegiate track and cross-country athletes for five years, mean follow-up 2.7 years. Thirty-four athletes — 12 men and 22 women — sustained 61 bone stress injuries. MRI grade (P = .004) and total-body bone mineral density (P = .030) were independent predictors of time to return to sport: higher grade and lower density, longer recovery. Trabecular sites, including the femoral neck, pubic bone and sacrum, had prolonged recovery. That cohort is US collegiate track and field, and the majority of the injured athletes in it were women, which is stated because it is a fact about the cohort and not because it converts into anyone's personal risk.

The usable point is this: how long a bone takes is set by how far along it already is when it is found — which is an imaging question, not a pain question. Every week of waiting is a week of moving along a continuum whose position determines the answer.

Combat sports contribute one located case, and it is instructive precisely because it is a single case. A 19-year-old female elite boxer presented with three months of bilateral wrist pain; MRI suggested a triangular fibrocartilage complex injury; she later developed shoulder pain and instability; plain radiographs of the scapula were unremarkable; ultrasound found cortical irregularity, and CT at three-month follow-up confirmed a scapular body stress fracture. That is a single case report — evidence that this can happen, and nothing at all about how often. It is included for one reason: normal X-rays did not rule out a fracture in the one boxer case in this literature, and no pain reading would have classified it either.

Nothing in the fetched evidence supports the idea that an athlete can distinguish a tendon problem from a bone stress injury by how it feels. Nobody should try.

8. Energy availability sits underneath the bone

One thread runs directly from the previous section into this site's subject matter, and it has to be stated without being quantified.

The International Olympic Committee's 2023 consensus statement describes Relative Energy Deficiency in Sport as a syndrome of health and performance outcomes arising from low energy availability, in female and male athletes, supported by more than 170 new original studies since the previous statement and accompanied by a revised clinical assessment tool. It is a consensus statement, not a trial.

The relevance to a weight-class sport is structural and obvious: these sports run energy restriction by design, often for long stretches of a camp rather than a fight week. The link between low energy availability and bone health is exactly the terrain on which the previous section's injuries live.

What this article will not do is convert that into a personal risk statement, a screening category or a set of thresholds. No number from that consensus tool appears here. If a fighter is restricting and has a bone-area complaint, that combination is information for a clinician, and the clinician needs to be told about the restriction as well as the pain. How the restriction interacts with an existing injury is treated separately in what an injury does to a weight cut.

9. What the loading research actually established

If a clinician has diagnosed a tendon problem, there is a real body of evidence on how to load it. It is worth knowing what that evidence does and does not say, because the gym version of it is usually one study taken out of its size.

Heavy slow resistance work has the best-known results in patellar tendinopathy. A 2009 trial compared corticosteroid injection, eccentric decline squat training and heavy slow resistance in 39 male patients over 12 weeks with a half-year follow-up. All three arms improved on the VISA-P questionnaire and on pain at 12 weeks. At follow-up, the gains were maintained in the eccentric and heavy slow resistance arms and had deteriorated in the steroid group, with the heaviest resistance arm reporting the highest treatment satisfaction. Thirty-nine male patients — men only, and a clinic population.

The mechanism work alongside it is smaller still: 8 male patients and 9 controls, 12 weeks of heavy slow resistance, with fibril density up 70 ± 18% and mean fibril area down 26 ± 21%, while the tendon's mechanical properties were normal at baseline and unchanged by the intervention. That last clause is the interesting one and is rarely repeated.

In the Achilles, a 2015 trial of 58 patients compared heavy slow resistance against eccentric training over 12 weeks with follow-up at 52 weeks and found both produced positive, equally good, lasting clinical results, with a satisfaction difference at 12 weeks that had gone by 52.

Those twelve-week figures are intervention durations. They are not healing times, and nothing in this literature establishes a healing time for a tendon.

The summary of the whole field belongs to a living systematic review with network meta-analysis covering 29 randomised controlled trials in Achilles tendinopathy, 22 of the 29 at high risk of bias. Its findings are two. Any treatment class seemed superior to wait-and-see at three months, on very low to low certainty. And, on the comparison everyone actually wants: "no trials were at low risk of bias and there was large uncertainty in the comparative estimates… There seems to be no clinically relevant difference in effectiveness between different active treatments at either 3-month or 12-month follow-up."

One more item, because it circulates in gyms with far more confidence than it earned. Isometric holds have been reported to produce immediate analgesia in patellar tendinopathy: pain on a single-leg decline squat fell substantially further after isometrics than after isotonic work, with the effect holding at least 45 minutes and with reduced cortical inhibition. That study had six volleyball players in it. It is a crossover mechanism study of an acute effect in one tendon in one sport. It is not an outcome study, it says nothing about other tendons, and it says nothing about combat sports. Treat the claim that isometrics abolish tendon pain as a six-person finding, because that is what it is.

10. Modify rather than stop — and the honest evidence for it

The middle ground between full training and full rest is the position most clinicians take, and it has better support than either extreme — though the support is not where people assume.

The pilot trial that examined pain-guided against pain-free activity in patellar tendinopathy was a feasibility study and said so: 108 screened, 47 eligible, 15 enrolled, nine in the pain-guided arm and six in the pain-free arm, not powered for clinical outcomes. Its useful finding is about adherence rather than tissue. Compliance was 86.1 ± 13.0% in the pain-guided group against 67.1 ± 30.7% in the restricted group. Two adverse events occurred, neither attributed to the interventions. A restriction that patients do not follow is not a treatment, and that is a real argument for the middle ground even before any tissue question is settled.

The authors' rationale for the middle ground is worth stating plainly in both directions, because it cuts both ways. Full rest carries psychological cost and deconditioning. Full participation "may reduce or nullify the benefits of exercise therapy, as patients lack the necessary recovery time for tendon remodeling." The second half of that sentence is the half fighters skip.

The strongest support for modifying rather than stopping comes from a body of work that has nothing to do with injury at all. Mujika and Padilla's two-part narrative review on detraining describes what happens when the training stimulus becomes insufficient. In the short term, under four weeks, highly trained athletes show a rapid decline in maximal oxygen uptake and blood volume, reduced maximal cardiac output, impaired endurance performance, reduced capillary density and oxidative enzyme activity, and reversal of training-induced fibre cross-sectional area — but "strength performance declines are limited." Over longer periods, maximal oxygen uptake "declines markedly but remains above control values," recently acquired gains are lost completely, and "[f]orce production declines slowly, and usually remains above control values for very long periods."

Then the line that matters for a camp: those losses "can be avoided or limited by reduced training strategies, as long as training intensity is maintained and frequency reduced only moderately," with volume markedly reducible.

That is a narrative review of general detraining in mixed athletic populations, not a study of injured athletes, and it is quoted here for what it is. But it is the most honest available answer to the fear that drives training through everything. The thing that erodes fastest is aerobic, and the thing that protects it is intensity rather than volume. A reduced programme is not the same object as stopping, and the physiological cost of the two is not remotely comparable. What that reduced programme should contain, for a specific injury, is a question for the clinician who examined it — and, in a camp, for the coach who has to rebuild the week around it.

11. Who makes the decision, and who is under pressure

The decision to train, modify or stop is not a measurement problem. It is a decision problem with several parties, and the sports medicine literature has been explicit about that for a decade.

The 2016 Bern consensus statement on return to sport frames it directly: "Deciding when to return to sport after injury is complex and multifactorial-an exercise in risk management," made every day by clinicians, athletes and coaches, ideally collaboratively, with return to sport understood as a continuum paralleling recovery and rehabilitation. It names the Strategic Assessment of Risk and Risk Tolerance framework as the synthesis. It also concedes, in its own abstract, that "[r]esearch evidence to support return to sport decisions in clinical practice is scarce." Seventeen expert clinicians at a half-day meeting produced that statement. It is consensus, not data, and it says so.

StARRT itself structures the judgement in three steps — tissue health, the tissue stresses the specific activity imposes, and risk tolerance modifiers. Its author's stated reason for making the reasoning explicit is worth quoting: "when reasoning is not explicit, unnecessary conflict can arise among clinicians themselves, or among clinicians and patients. This conflict can have negative health consequences for the patient." For a fighter, the middle step is where the sport lives. A shot defence, a scramble, a check and a clinch load the same tissue in entirely different ways, and "can I train" is not a question with one answer even within a single session.

The uncomfortable half is measured rather than speculated. A survey of Canadian sport medicine physicians, physiotherapists, athletic therapists, chiropractors, massage therapists, athletes, coaches and three sport associations asked who was best able to assess what. Doctors, physiotherapists and athletic therapists were rated best able to assess the risk of injury and complications. Athletes, coaches and associations were rated best able to assess desire, psychological and financial impact, and loss of competitive standing.

Read the second sentence slowly. The factors that push toward competing sit with the people who want to compete. That is not an accusation; it is a description of where different kinds of knowledge live. The same survey found that differences in approach to these decisions were generally greater within stakeholder groups than between them — so "ask a physio" is not a stable answer either, and the individual clinician matters more than the profession. Each clinician group, incidentally, generally believed its own profession had the best capacity to judge. The survey is self-report, from Canada, on a ten-minute online instrument, and the response numbers are not in the fetched abstract.

None of this argues for concealing anything. It argues the opposite: the decision improves when the reasoning is explicit and the person who can examine the tissue is actually given the information. Telling your coach you are hurt is the practical version of that problem.

12. Four questions about the same shin

Take a generic, invented situation to show how little of this converges on a single answer. Six weeks out from a fight, the lead shin aches after every round of pad work and is stiff in the morning. No incident, no swelling anyone can point to, no missed sessions.

Four bodies of evidence ask four different questions about that shin, and none of them can be answered from the sofa.

The surveillance question. If the only thing being recorded is whether he missed a session, the shin is invisible. In the Norwegian cohort, an average of 39% of athletes reported an overuse problem in any given week, and over the same thirteen weeks the questionnaire recorded 419 overuse problems where standard time-loss registration recorded 40 — two counts of different things, which is the point. "I have not missed a session" is a fact about the calendar.

The tissue question. A tendon and a bone can produce that same complaint. Bone stress sits on a continuum that ends in a fracture, and how far along it is determines how long it takes. The boxer case is the illustration: unremarkable radiographs, a real fracture, confirmed on CT three months later. This is an imaging and examination question, and it is the point at which the article stops being useful and a clinician starts.

The loading question. If a clinician has diagnosed a tendinopathy, there are published monitoring models, each with its own ceiling for its own tendon, and in one 38-patient Achilles trial continuing to load under such a model did not produce worse outcomes than stopping. Which model, which tendon, which number, and whether any of it applies is not something the athlete assigns to himself.

The decision question. Bern frames this as risk management, collaborative by design. Shrier's survey is the uncomfortable half: the people best placed to weigh desire, money and competitive standing are the athlete, the coach and the promotion — and those are the factors pushing toward the fight. Naming that pressure is not cynicism. It is the measured finding.

What the athlete can do without deciding anything medical is make the shin legible: when it started, what provokes it, what it does the next morning, what has been modified and for how long. That record is what turns a five-minute conversation into a useful one. It is not a substitute for the conversation.

What we could not verify

• No pain-monitoring model has been validated in any combat sport. Every threshold source located is Achilles, patellar or proximal hamstring tendinopathy, in runners, jumpers, volleyball players or mixed clinic populations. The overuse surveillance cohort is cycling, floorball, handball, volleyball and cross-country skiing — no striking, no grappling. The only combat-sport items found at all are a self-report BJJ survey and a single boxer case report.
• "Pain under a given level means it is safe to train" was refused. The figure exists, but as an instruction inside a supervised programme for a diagnosed tendinopathy, paired with a next-morning condition and a week-to-week trend rule, for patients a clinician had examined. Nothing found validates it as a decision rule for undiagnosed pain, and nothing validates it for bone, joint, nerve, ligament, acute injury or head impact. No numeric threshold appears anywhere in this article for that reason.
• "The twenty-four-hour rule" was refused as a singular object. There are at least two next-day conditions in this literature, attached to different tendons, worded differently, doing different jobs. Presenting one as the rule would be inventing a consensus.
• The commonly repeated lower threshold was refused. The closest sourced statement describes a figure as the most commonly used threshold across tendinopathy protocols — a statement about convention. It is not a validated cut-point and it is not a permission to train.
• "Tendinopathy heals in twelve weeks" was refused. Twelve weeks is the intervention duration in the resistance-training trials cited here, not a healing time, and the network meta-analysis of the Achilles literature reports large uncertainty in all comparative estimates.
• Fighter-specific overuse prevalence could not be established. The 39% and 13% weekly figures belong to five non-combat sports and three body areas in Norway, and were not extrapolated. No source located measures what share of fighters train through injury, and the BJJ survey has no exposure denominator that would allow such a figure to be computed.
• Parts of the surveillance paper could not be re-checked. The abstract confirms the 419 problems, the 142 substantial, the 40 by standard registration, and the 39% and 13% weekly averages. Several figures in the research sheet came from the full text — the number of individual athletes affected, the share of cases already present at the study's start, the per-site prevalences and the effect of questioning every four weeks instead of weekly — and the author-hosted copy of that full text now returns an error. Those figures are not printed here. They are not claimed to be wrong; they could not be reached.
• Women are thinly represented in the threshold literature. The patellar tendinopathy trials cited here are male-only, at 39 and 8 patients. The one cohort where women dominate is the bone stress injury study, in which 22 of 34 injured athletes were women. No sex-specific pain threshold exists in anything located, and sex differences in bone and energy availability are pathway differences, not multipliers.
• Adolescents are absent. The pilot trial enrolled from age 16 upward and everything else is adult. Nothing here was developed or validated in young athletes, whose growth-plate injuries are a different problem entirely, and adult findings do not scale down.
• Recreational athletes are absent too. The surveillance cohort is elite and sub-elite, the tendon trials are clinic patients, and the pilot's authors note that it under-recruited high-level athletes and recommend greater recruitment of them in future work. The person training three evenings a week around a job is in none of these cohorts.
• The upper limb is barely covered. The pain-monitoring literature is overwhelmingly lower-limb tendon. Nothing located covers finger pulleys, the elbow, the neck, or the shoulder under submission load.
• Acute injuries are not covered by any of it. Every framework here is for overuse, tendinopathy or bone stress. None covers a sprain, a tear, an acute joint injury sustained in sparring, or a head impact.
• Bone stress injury healing has no agreed definition. A 2026 multi-site study protocol states plainly that there is no consensus on how to define or assess it, and that clinical, functional and imaging outcomes are used inconsistently across studies. That protocol has no results yet.

Sources

Sourced to

1. Development and validation of a new method for the registration of overuse injuries in sports injury epidemiology: the Oslo Sports Trauma Research Centre (OSTRC) overuse injury questionnaire — Clarsen B, Myklebust G, Bahr R, British Journal of Sports Medicine 2013;47(8):495–502. DOI 10.1136/bjsports-2012-091524, PMID 23038786. Figures used here are those stated in the abstract; the author-hosted full text returned an error when re-checked on 22 September 2026
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17. Bone stress injury recovery and return to sport in runners: a multi-site prospective observational cohort study protocol across the USA and Canada — Popp KL, Whitcomb E, Hahn ME et al., BMJ Open 2026. DOI 10.1136/bmjopen-2026-121916, PMID 42637262, PMC13504497. Study protocol; no results yet
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20. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs) — Mountjoy M, Ackerman KE, Bailey DM et al., British Journal of Sports Medicine 2023;57(17):1073–1097. DOI 10.1136/bjsports-2023-106994, PMID 37752011
21. Prevalence of Injuries during Brazilian Jiu-Jitsu Training — McDonald AR, Murdock FA, McDonald JA, Wolf CJ, Sports (Basel) 2017;5(2):39. DOI 10.3390/sports5020039, PMID 29910398, PMC5968975. Self-report survey, recall-based, no exposure denominator
22. Ultrasonographic Diagnosis and Computed Tomographic Confirmation of a Scapular Body Stress Fracture in an Elite Boxer: A Case Report — Yoon Y, Lam KHS, Hwang J et al., Diagnostics (Basel) 2025;15(20):2565. DOI 10.3390/diagnostics15202565, PMID 41153238, PMC12563319. Single case report

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