Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.

The importance of the muscle-tendon complex in sport and for activities of everyday living is well recognised. The free oscillation technique is frequently used to determine the musculo-articular "apparent" stiffness (obtained from vertical ground reaction force) and other parameters. Howe...

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Main Authors: Aurélio Faria, Ronaldo Gabriel, Rui Brás, Helena Moreira, Márcio Soares, Massimiliano Ditroilo
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2023-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0286847
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author Aurélio Faria
Ronaldo Gabriel
Rui Brás
Helena Moreira
Márcio Soares
Massimiliano Ditroilo
author_facet Aurélio Faria
Ronaldo Gabriel
Rui Brás
Helena Moreira
Márcio Soares
Massimiliano Ditroilo
author_sort Aurélio Faria
collection DOAJ
description The importance of the muscle-tendon complex in sport and for activities of everyday living is well recognised. The free oscillation technique is frequently used to determine the musculo-articular "apparent" stiffness (obtained from vertical ground reaction force) and other parameters. However, an in-depth understanding of the muscle-tendon complex can be gained by separating the muscle (soleus) and the tendon (Achilles tendon) components and studying the "true" stiffness for each of these components (by considering the ankle joint moment arms), which can be valuable in improving our understanding of training, injury prevention, and recovery programs. Hence, this study aimed to investigate if muscle and tendon stiffness (i.e., "true" stiffness) are similarly affected by different impulse magnitudes when using the free-oscillation technique. Three impulse magnitudes (impulse 1, 2 and 3), corresponding to peak forces of 100, 150 and 200 N, were used to estimate the stiffness of the ankle joint in 27 males, using multiple loads (10, 15, 20, 25, 30, 35, and 40 kg). A significant decrease (p < 0.0005) was found in musculo-articular "apparent" stiffness (29224 ± 5087 N.m-1; 27839 ± 4914 N.m-1; 26835 ± 4880 N.m-1) between impulses 1, 2 and 3 respectively, when loads were collapsed across groups. However, significant differences (p < 0.001) were only found between the median (Mdn) of impulse 1 (Mdn = 564.31 (kN/m)/kN) and 2 (Mdn = 468.88 (kN/m)/kN) and between impulse 1 (Mdn = 564.31 (kN/m)/kN) and 3 (Mdn = 422.19 (kN/m)/kN), for "true" muscle stiffness, but not for "true" tendon stiffness (Mdn = 197.35 kN/m; Mdn = 210.26 kN/m; Mdn = 201.60 kN/m). The results suggest that the musculo-articular "apparent" stiffness around the ankle joint is influenced by the magnitude of the impulse applied. Interestingly, this is driven by muscle stiffness, whereas tendon stiffness appears to be unaffected.
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spelling doaj.art-c0ee43196f0c45b9a8f6fa0d32b620c22023-06-20T05:30:57ZengPublic Library of Science (PLoS)PLoS ONE1932-62032023-01-01186e028684710.1371/journal.pone.0286847Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.Aurélio FariaRonaldo GabrielRui BrásHelena MoreiraMárcio SoaresMassimiliano DitroiloThe importance of the muscle-tendon complex in sport and for activities of everyday living is well recognised. The free oscillation technique is frequently used to determine the musculo-articular "apparent" stiffness (obtained from vertical ground reaction force) and other parameters. However, an in-depth understanding of the muscle-tendon complex can be gained by separating the muscle (soleus) and the tendon (Achilles tendon) components and studying the "true" stiffness for each of these components (by considering the ankle joint moment arms), which can be valuable in improving our understanding of training, injury prevention, and recovery programs. Hence, this study aimed to investigate if muscle and tendon stiffness (i.e., "true" stiffness) are similarly affected by different impulse magnitudes when using the free-oscillation technique. Three impulse magnitudes (impulse 1, 2 and 3), corresponding to peak forces of 100, 150 and 200 N, were used to estimate the stiffness of the ankle joint in 27 males, using multiple loads (10, 15, 20, 25, 30, 35, and 40 kg). A significant decrease (p < 0.0005) was found in musculo-articular "apparent" stiffness (29224 ± 5087 N.m-1; 27839 ± 4914 N.m-1; 26835 ± 4880 N.m-1) between impulses 1, 2 and 3 respectively, when loads were collapsed across groups. However, significant differences (p < 0.001) were only found between the median (Mdn) of impulse 1 (Mdn = 564.31 (kN/m)/kN) and 2 (Mdn = 468.88 (kN/m)/kN) and between impulse 1 (Mdn = 564.31 (kN/m)/kN) and 3 (Mdn = 422.19 (kN/m)/kN), for "true" muscle stiffness, but not for "true" tendon stiffness (Mdn = 197.35 kN/m; Mdn = 210.26 kN/m; Mdn = 201.60 kN/m). The results suggest that the musculo-articular "apparent" stiffness around the ankle joint is influenced by the magnitude of the impulse applied. Interestingly, this is driven by muscle stiffness, whereas tendon stiffness appears to be unaffected.https://doi.org/10.1371/journal.pone.0286847
spellingShingle Aurélio Faria
Ronaldo Gabriel
Rui Brás
Helena Moreira
Márcio Soares
Massimiliano Ditroilo
Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.
PLoS ONE
title Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.
title_full Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.
title_fullStr Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.
title_full_unstemmed Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.
title_short Free-oscillation technique: The effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle.
title_sort free oscillation technique the effect of the magnitude of the impulse applied on muscle and tendon stiffness around the ankle
url https://doi.org/10.1371/journal.pone.0286847
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