Evidence map›Paper›PMID 40630389›Full record

ArticleFrontiers in physiology2025

Reliability and reproducibility of the Kinvent K-push dynamometer for assessing quadriceps strength and force development in athletes and untrained individuals.

Robert Trybulski, Jakub Więckowski, Jarosław Muracki, Filip Matuszczyk, Kamil Gałęziok, Michał Wilk, Adrian Kużdżał

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Article in Frontiers in physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

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5citing papers in PubMed
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1 · What the graph read from it

What it found

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2 · The registry

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3 · Its place in the literature

Who cites it

5 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Robert TrybulskiMedical Department, Wojciech Korfanty Upper Silesian Academy, Katowice, Poland.
Jakub WięckowskiNational Institute of Telecommunications, Warsaw, Poland.
Jarosław MurackiDepartment of Physical Culture and Health, Institute of Physical Culture Sciences, University of Szczecin, Szczecin, Poland.
Filip MatuszczykProvita Medical Center, Żory, Poland.
Kamil GałęziokProvita Medical Center, Żory, Poland.
Michał WilkJerzy Kukuczka Academy of Physical Education, Katowice, Poland.
Adrian KużdżałInstitute of Physiotherapy Faculty of Health Sciences and Psychology Collegium Medicum, University of Rzeszów, Poland.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Objectives: This study aimed to (1) analyze the reliability of the Kinvent K-push handheld dynamometer for assessing quadriceps maximum voluntary contraction (MVC) and rate of force development (RFD), and (2) evaluate inter-rater reliability by assessing the reproducibility of measurements between examiners. Methods: A blinded, randomized, comparative study evaluated the reliability of quadriceps femoris MVC and RFD measurements obtained by two independent researchers. Forty-four male volunteers participated, divided into three groups based on motor skill level: elite mixed martial arts (MMA) athletes (n = 15), amateur football players (n = 15), and untrained healthy volunteers (n = 14). Three measurements per leg were taken during the experimental session, with the Kinvent K-push handheld dynamometer automatically calculating the average MVC and RFD. Results: Pearson correlations revealed that MVC and RFD measurements were highly consistent, with the left quadriceps showing nearly perfect correlations (r = 0.96 for MVC, r = 0.97 for RFD), while the right quadriceps displayed more variability, particularly in MVC. Inter-examiner comparisons showed high reproducibility, with minimal differences between the two measurers (p > 0.05). The ICC further supported this, with very high intraclass correlation values, especially for RFD (ICC = 0.999), confirming almost perfect agreement between the measurers. Group comparisons revealed that athletes, particularly MMA fighters and footballers, had significantly higher muscle strength and RFD compared to the general non-training group (p < 0.05), with athletes showing similar values for both MVC and RFD, while the general non-training group exhibited greater variability in both parameters. Bland-Altman analysis revealed strong agreement between measurers across all quadriceps measurements, with minimal systematic bias and acceptable variability, particularly in MVC assessments. Conclusion: MVC and RFD measurements in the quadriceps using the K-push handheld dynamometer are highly reliable and consistent, with minimal inter-examiner variability. These findings, in conjunction with high ICC and low MAE/MSE values, underscore the reliability of the measurement protocol used in this study. The tested instrument provides consistent and accurate results, ensuring reliable measurements across different examiners.

Indexed as

assessment stabilityfootballermaximum voluntary contractionMMArate of force development

Identifiers

PMID40630389
PMCPMC12234502

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