Evidence map›Paper›PMID 42399981›Full record

ArticleBMC sports science, medicine & rehabilitation2026

Blunted exercise-induced hypoalgesia in people with knee pain after a brief low-intensity warm-up: a split-body study with and without blood flow restriction.

Yunfeng Zhang, Peng Zhang, Fanjun Qin, Yanjie Hu, Bingbing Pu, Haozhe Qu, Xiaodi Xia, Zhaodong Bi, Yefan Cao, Liyi Chen and 4 more

Abstract read
In one paragraph

Article in BMC sports science, medicine & rehabilitation, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Observational
4 · The record

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5 · Who and what money

Authors and funding

14 authors.

Yunfeng Zhang *Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China.
Peng Zhang *Department of Rehabilitation Medicine, The Fifth Affiliated Hospital of Sun Yat-Sen University, Guangdong, 519000, China.
Fanjun Qin *Department of Rehabilitation, Shanghai Pudong Hospital, Fudan University Affiliated Pudong Medical Center, Shanghai, 200120, China.
Yanjie HuDepartment of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China.
Bingbing PuDepartment of Rehabilitation, Shanghai Pudong Hospital, Fudan University Affiliated Pudong Medical Center, Shanghai, 200120, China.
Haozhe QuDepartment of Rehabilitation, Shanghai Pudong Hospital, Fudan University Affiliated Pudong Medical Center, Shanghai, 200120, China.
Xiaodi XiaDepartment of Rehabilitation Medicine, Shanghai Hebin Rehabilitation Hospital, Shanghai, 201702, China.
Zhaodong BiDepartment of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China.
Yefan CaoDepartment of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China.
Liyi ChenDepartment of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China.
Ziheng MaoDepartment of Rehabilitation Medicine, Shanghai Hebin Rehabilitation Hospital, Shanghai, 201702, China.
Yanzheng ZhangDepartment of Rehabilitation Medicine, Shanghai Hebin Rehabilitation Hospital, Shanghai, 201702, China.
Qiang LiuDepartment of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China. leon5464@163.com.
Hewei WangDepartment of Rehabilitation, Huashan Hospital, Fudan University, Shanghai, 200040, China. wanghew@fudan.edu.cn.

Funding

National Natural Science Foundation of China 82102665Shanghai Sailing Program 21YF1404600
6 · The paper itself

Abstract

backgroundExercise-induced hypoalgesia (EIH) is vital for rehabilitation, but its efficacy in patients with knee pain remains controversial. Blood flow restriction (BFR) might augment analgesia through metabolic accumulation. This study aimed to investigate the acute analgesic impact of a low-intensity warm-up with or without BFR and to compare EIH responses between healthy individuals and patients with persistent knee pain.

methodsForty-six participants (healthy controls: n = 26; participants with persistent knee pain: n = 20) were enrolled in a single-session, within-subject split-body protocol. BFR at 70% arterial occlusion pressure was applied to one limb during a 5-min low-intensity warm-up. The BFR-treated limb was randomized in healthy controls, whereas in participants with persistent knee pain, BFR was consistently applied to the symptomatic limb, with the contralateral asymptomatic limb serving as the within-subject comparison. Pressure pain thresholds (PPT) were measured at three peri-patellar sites pre- and post-condition using a Latin Square design. Data were analyzed via Linear Mixed Models.

resultsHealthy controls showed a robust increase in PPT after warm-up (+ 5.55 N, 95% CI, 4.20 to 6.90), whereas participants with persistent knee pain showed no clear increase (+ 0.15 N, 95% CI, -1.39 to 1.69). The between-group difference in EIH was significant (+ 5.40 N, 95% CI, 3.36 to 7.45, p < 0.001). The EIH response was markedly attenuated in participants with persistent knee pain, a finding consistent with altered endogenous pain modulation. However, the present data do not directly identify the central or peripheral mechanisms underlying this attenuation. The additional BFR effect was small and not statistically significant (-0.14 N; 95% CI, -2.18 to 1.91; p = 0.894), suggesting the tested BFR protocol did not demonstrate statistically superior additional hypoalgesic effects compared with the non-BFR condition.

conclusionA brief low-intensity warm-up induced a clear EIH response in healthy controls, whereas participants with persistent knee pain showed a markedly attenuated response. The tested BFR protocol did not demonstrate statistically superior additional hypoalgesic effects compared with the non-BFR condition. These exploratory findings warrant further investigation using adequately powered, prespecified, and mechanistically informed studies.

trial registrationChinese Clinical Trial Registry ChiCTR2300069386 ( https://www.chictr.org.cn/ , registered on 15 March 2023).

Indexed as

Blood flow restrictionEndogenous pain modulationExercise-induced hypoalgesia; Knee painPressure pain thresholdWarm-up

Identifiers

PMID42399981
PMCPMC13543522

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.