Science
The research the BLOCKS assistant answers from: 1,118 studies and 81 guides, each graded for how strong the evidence is and who it was measured on, with a link to the original paper.
102 entries in Running, injury & shoes
C+Five things must be addressed before a runner runs again after a tibial bone stress injuryThen an individualised walk-run return, distance before speed, gated by symptoms rather than a calendar; all resting on level IV evidenceGeorge 2024AThere is now an international consensus on bone stress injuriesAnd its headline number is that a 41-member panel could agree on only 41 of 58 statements, so a confident single answer about grading, screening or return timing is over-claimingHoenig 2025C+How much do elite ultrarunners eat and spend in a hot 100-miler?One world-class runner: 16,104 kcal spent, ~6,400 eaten in race (86 g carbs/h), no distress reported, −4.3% mass. One case, not a target.Mougin 2026BHold length matters for tendon, not for strength12 weeks of isometric knee extension at 70% MVC with matched volume: 20-s holds and 1-s pulses built the same strength (+34% vs +32%) and quadriceps volume (+7.6% vs +7.4%), but only the 20-s holds…Kubo 2001BAchilles tendon adaptation has a strain threshold14 weeks of isometric plantarflexion at matched frequency and volume stiffened the tendon, raised its modulus and thickened it regionally only in the leg loaded to ~4.6% tendon strain (90% MVC), not…Arampatzis 2007A-Healthy lower-limb tendons stiffen with loading (stiffness SMD 0.74, modulus 0.82, cross-section only 0.22 across 61 studies), the gain is mostly a material change, resistance training works best, and protocols that reached high tendon strain (~5%) beat low-strain ones (~3%)A contrast that rests on three high-strain intervention groups from the few studies that measured strainLazarczuk 2022A-Effectiveness of isometric exercise in tendinopathyAcross 10 small RCTs (294 participants, five tendon sites) isometrics were not superior to isotonic exercise for pain, either straight after a session (3 patellar trials pooled, p = 0.19) or over up…Clifford 2020BAcute sensory and motor response to 45-s heavy isometric holds for the plantar flexors in Achilles tendinopathyFive 45-s calf holds at 70% MVC gave no immediate pain relief (functional pain 4.2 → 4.9 of 10, not significant, in the 9 of 16 who had pain to test), no change in pressure pain, and the most painful…O'Neill 2019B+Isometric exercise and pain in patellar tendinopathy, a pre-registered crossover replication of Rio 2015One session of 5 × 45-s quadriceps holds at 70% MVIC was no better than dynamic leg extensions: pain on the decline squat fell only 0.9 of 10 across both, had drifted back by 45 min, and 4 of 20…Holden 2020BIn-season jumping athletes with patellar tendinopathy who kept training and competing: 4 weeks of isometric or isotonic leg exercise, 4 sessions a week, both reduced decline-squat pain, with no difference between them (median change 2.5 vs 3.0 of 10, p = 0.208); n=29 randomised, about 19 analysedvan Ark 2016B+Isometric contractions are more analgesic than isotonic contractions for patellar tendon pain in-seasonOver 4 weeks of 4 sessions a week, isometric leg-extension holds eased decline-squat pain within each session more than isotonic leg extensions (P < 0.002), both programmes reduced pain, n=20; the…Rio 2017BExperienced recreational runners who gradually transitioned to Vibram FiveFingers over 10 weeks showed more bone marrow oedema on foot MRI than runners who stayed in their usual shoes: 10 of 19 had an increase in at least one bone (P = 0.009 vs control)Ridge 2013B+RCT in 320 novice runners: 2 weeks of gait retraining with real-time visual feedback aimed at lowering impact loading cut loading rates (d > 0.99) and was followed by 16% vs 38% running injury over 12 months (HR 0.38, 95% CI 0.25-0.59, 62% lower risk) versus treadmill running without feedbackChan 2018B550 injured recreational runners on an instrumented treadmill: strike pattern and peak vertical force were the only biomechanical variables that set one injury location apartMidfoot strike went with Achilles tendon injuries (OR 2.27), forefoot strike with posterior lower-leg injuries (OR 2.59), peak vGRF weakly with hip injuries (OR 1.14); loading rate and cadence did…Hollander 2021B+827 US Military Academy cadets followed through 9 weeks of basic training: the longest ground contact times (>0.42 s) went with 2.15× the risk of overuse lower-extremity injury after adjustment, the shortest stride length with 45% more overuse injury (univariate), and foot strike pattern and cadence were not associated with injuryHelton 2025B+Systematic review of 13 studies on foot strike technique and running-related injury: low evidence for any relationship; 3 of 6 categorical studies found more retrospective injury in rearfoot strikers and 1 found more risk with mid/forefoot strike, but these were very low quality; only 1 of 7 continuous-measure studies found a relationshipBurke 2021C+Narrative critique of the case for switching from a rearfoot to a mid- or forefoot strike: the authors conclude that the switch does not improve running economy, does not eliminate the impact at foot-ground contact and does not reduce the risk of running-related injury; the rearfoot strike is clearly the more prevalent patternHamill 2017B-In 52 collegiate cross-country runners, about 74% had a moderate or severe injury each year; habitual rearfoot strikers had about twice the rate of repetitive stress injuries of habitual forefoot strikers, while traumatic injury rates did not differ significantlyThe abstract names no Achilles, calf or metatarsal resultsDaoud 2012A-Review of 53 studies: non-rearfoot strikers report fewer repetitive stress injuries in retrospective data only, habitual non-rearfoot and rearfoot runners have the same running economy, imposing a non-rearfoot strike on rearfoot runners worsens economy in the immediate term, and loading shifts from knee to ankleChanging strike pattern cannot be recommended for an uninjured rearfoot runnerAnderson 2020A-Meta-analysis of 16 studies in adult distance runners: forefoot strikers land with a plantar-flexed ankle and a more flexed knee, and rearfoot strikers have higher vertical loading rates; the abstract reports kinematics and loading rate onlyRunning economy was not an outcome, and no knee-versus-Achilles load comparison is reportedAlmeida 2015BNatural forefoot-striking women (n=19) had lower patellofemoral contact force (4.3 vs 5.1 body weights) and stress (11.1 vs 13.0 MPa) and a lower knee frontal-plane moment than matched rearfoot strikers (n=19) at 4 m/s, but a higher ankle plantarflexor moment (3.12 vs 2.54 N·m/kg) and Achilles tendon force (6.3 vs 5.1 body weights)Kulmala 2013BHabitual rearfoot and forefoot strikers at 4.5 m/s did the same total lower-limb work and average power; the load sat at the knee in rearfoot and at the ankle in forefoot running, and rearfoot strikers switched to an imposed forefoot strike raised the ankle internal rotation moment by 33%, kept knee abduction moments 48.5% above habitual forefoot strikers and raised total positive limb power by 17%Stearne 2014BHabitual rearfoot (n=19) and forefoot (n=18) runners on a treadmill at 3.0, 3.5 and 4.0 m/s: with their own pattern the groups did not differ in oxygen cost or carbohydrate use; switching to forefoot raised both in rearfoot runners at 3.0 and 3.5 m/s, switching to rearfoot changed nothing in forefoot runners, and at 4.0 m/s the forefoot pattern cost more oxygen with no difference in carbohydrate shareGruber 2013B2017 IAAF World Championship men's 10,000 m final (top 12 finishers, filmed on six laps): no rearfoot strikes at all, forefoot and midfoot strikers in similar numbers with similar finishing times, and no change in pattern even when speed fell and contact time rose mid-raceHanley 2024A-Systematic review and meta-analysis of overground distance running (> 10 km, 12 studies): 79% of runners rearfoot strike early and 86% with increased distance; 11% change pattern, 84% of those from non-rearfoot to rearfoot; evidence for a performance advantage of non-rearfoot striking is inconclusive (5 studies for, 1 in women only, 4 no benefit, none favouring rearfoot)Bovalino & Kingsley 2021BAt 8.1 km of a mid-size city marathon (1991 runners classified), 93.67% were heel strikers; foot-strike class differed with race position (Kruskal-Wallis P <.0001), with faster runners less likely to heel strike, and it did not differ by genderKasmer 2013B2017 IAAF World Championship marathons (71 men, 78 women filmed at ~8.5, 19, 29.5 and 40 km): rearfoot striking was the most common pattern at every point (never below 54% of men or 67% of women), it did not separate top from bottom halves of the men's field, and more than 75% of athletes kept the same pattern across lapsHanley 2019BFilmed at 15 km of an elite-level half marathon (283 runners analysed): 74.9% rearfoot, 23.7% midfoot and 1.4% forefoot strikers; in the fastest group of 50 the split was 62.0 / 36.0 / 2.0%, so midfoot striking became more common with speed, and rearfoot contact time was longer than midfoot + forefoot (200.0 vs 183.0 ms)Hasegawa 2007B+A single run more than 10% longer than the longest run of the previous 30 days raised the rate of overuse running injury (HRR 1.52-2.28 by size of spike) in 5205 adult runners followed for 18 months with Garmin data; week-to-week change showed no relationFrandsen 2025BRecreational (half-)marathon runners (n=997): higher weekly volume and a longer longest run went with faster finish times; for the marathon a longest run under 25 km went with a slower finish (β 13.44, units not stated, likely minutes); no training characteristic was associated with injuryFokkema 2020BAfter a marathon, peak pressure rises under the metatarsal heads and falls under the toesThe load shifts from the toes to the forefootNagel 2008B-Over a 100-km ultramarathon mean foot volume did not changeIt fell in half the runners — and an increase went with higher fluid intake and slower runningCejka 2012B+No blister-prevention method has high-quality evidence; paper tape is the only one with moderate confidence, and the data on socks and antiperspirants come from military marchingWorthing 2017B+Paper tape applied before the race to a runner's own blister-prone spots cut blisters by 40% in multistage desert ultrasYet 83% of runners still blistered somewhereLipman 2016B+Clinical guideline for ankle sprains: judge severity at 4–5 days, treat with a brace or tape plus an exercise programme, prefer supervised exercise to passive treatments, and be careful with NSAIDsVuurberg 2018A-After a grade 1–2 ankle sprain, therapeutic exercise started in the first week improved function at weeks 1 and 2 compared with rest, ice, compression and elevation, with no more pain, swelling or re-injuryBleakley 2010C+Return to sport after a lateral ankle sprain is decided on 16 items in five domainsPain, ankle impairments, athlete perception, sensorimotor control and sport performance — not on a number of daysSmith 2021AThe Ottawa ankle rules exclude a fracture after an ankle injury with 97.6% sensitivity: being unable to walk four steps or having bone tenderness at specific points means an X-rayBachmann 2003A-An evaluation of the training determinants of marathon performance: A meta-analysis with meta-regressionDoherty 2020B+The treatment of medial tibial stress syndrome in athletes; a randomized clinical trialMoen 2012