Evidence map›Paper›PMID 42860733›Full record

ArticlePhysical activity and nutrition2026

Effects of keiser-assisted Nordic hamstring curl training on hamstring flexibility, mechanical properties, and pitching performance in high school baseball pitchers.

Ye-Jun Han, Hyun Ahn, Sea-Hyun Bae, Kyung-Yoon Kim

Abstract read
In one paragraph

Article in Physical activity and nutrition, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

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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

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Ye-Jun HanDepartment of Physical Therapy, Samsung Electronic Musculoskeletal Disorders Prevention Center, Gwangju, Republic of Korea.
Hyun AhnSocial Healing Team, National Trauma Recovery Center, Gwangju, Republic of Korea.
Sea-Hyun BaeDepartment of Physical Therapy, Dongshin University, Naju, Republic of Korea.
Kyung-Yoon KimDepartment of Physical Therapy, Dongshin University, Naju, Republic of Korea. redbead7@daum.net.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThis study aimed to investigate the effects of 10-week Keiser-assisted Nordic hamstring curl (NHC) training on the mechanical properties, muscle strength, and flexibility of the hamstrings, as well as shoulder range of motion (ROM) and pitching performance in high school baseball pitchers.

methodsSixteen high school baseball pitchers performed Keiser assisted NHC training for 10 weeks. The pre- and post-training measurements included the mechanical properties of the hamstrings (muscle tone, stiffness, elasticity, creep) measured using MyotonPRO, isometric muscle strength, trunk and shoulder ROM, and pitching performance (velocity and spin rate).

resultsAfter training, hamstring muscle tone, stiffness, and elasticity significantly decreased (p < 0.01), whereas creep and isometric strength significantly improved (p < 0 0.001) (effect size dz = 0.84-2.90). Additionally, the trunk flexion range significantly increased (p < 0.001, dz = 2.12), and the glenohumeral internal rotation deficit in the throwing shoulder significantly improved (p < 0.05). The pitching velocity (p < 0.001, dz = 2.61) and spin rate (p < 0.01, dz = 0.89) significantly increased.

conclusionKeiser-assisted NHC training improved hamstring mechanical efficiency, isometric strength, and trunk flexibility, with concurrent gains in pitching velocity and spin rate. As this was a single-group pre-post study without a control group, these findings require confirmation through controlled trials.

Indexed as

baseball pitchershamstring flexibilityinjury preventionmechanical propertiesNordic hamstring curlpitching performance

Identifiers

PMID42860733
PMCPMC13655424

What OpenQuestion holds

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Registered trials

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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.