The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.

<h4>Introduction</h4>The single-leg heel raise test (SLHR) is commonly used in clinical settings to approximate plantar flexor strength, yet this is neither validated nor supported physiologically. The purposes of this study were to: determine (1) associations between SLHR repetitions, m...

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Main Authors: Lauren K Sara, Savannah B Gutsch, Sandra K Hunter
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2021-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0253276
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author Lauren K Sara
Savannah B Gutsch
Sandra K Hunter
author_facet Lauren K Sara
Savannah B Gutsch
Sandra K Hunter
author_sort Lauren K Sara
collection DOAJ
description <h4>Introduction</h4>The single-leg heel raise test (SLHR) is commonly used in clinical settings to approximate plantar flexor strength, yet this is neither validated nor supported physiologically. The purposes of this study were to: determine (1) associations between SLHR repetitions, maximal plantar flexor strength, and reductions in strength; and (2) whether sex differences exist in performance of the SLHR.<h4>Methods</h4>Twenty-eight young, healthy participants (14 males,14 females, 19-30 years) performed repeated single-leg heel raises to task failure. Pre- and post-task measures included maximal voluntary isometric contractions (MVIC), and voluntary activation and contractile properties of the plantar flexor muscles, assessed using peripheral electrical stimulation of the tibial nerve. Surface electromyography was recorded for the medial and lateral gastrocnemius, soleus, and anterior tibialis muscles.<h4>Results</h4>The SLHR resulted in 20.5% reductions in MVIC torque (p<0.001). However, the number of SLHR repetitions was not correlated with either the baseline MVIC (maximal strength; p = 0.979) or the reduction in MVIC following the SLHR (p = 0.23). There were no sex differences in either the number of SLHR repetitions (p = 0.14), baseline MVIC torque (p = 0.198), or the reduction of MVIC (p = 0.14). MVIC decline was positively associated with the reduction in voluntary activation (r = 0.841, p<0.001), but was not associated with the change in twitch amplitude (p = 0.597).<h4>Conclusions</h4>The SLHR was similar in young males and females yet was a poor predictor of maximal plantar flexor strength but evaluates performance fatigability of the lower extremity specific to dynamic contractions. The reduction in maximal strength at task failure was explained by reduced neural drive to the plantar flexor muscles in both males and females.<h4>Impact statement</h4>SLHR performance is not a clinical assessment of plantar flexor strength but assesses dynamic lower extremity fatigability that is similar in males and females. Alternate clinical measures for maximal plantar flexion strength need to be developed.
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spelling doaj.art-21c5a4b336df42efbd6fe45b98c95bb32022-12-22T00:36:36ZengPublic Library of Science (PLoS)PLoS ONE1932-62032021-01-01168e025327610.1371/journal.pone.0253276The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.Lauren K SaraSavannah B GutschSandra K Hunter<h4>Introduction</h4>The single-leg heel raise test (SLHR) is commonly used in clinical settings to approximate plantar flexor strength, yet this is neither validated nor supported physiologically. The purposes of this study were to: determine (1) associations between SLHR repetitions, maximal plantar flexor strength, and reductions in strength; and (2) whether sex differences exist in performance of the SLHR.<h4>Methods</h4>Twenty-eight young, healthy participants (14 males,14 females, 19-30 years) performed repeated single-leg heel raises to task failure. Pre- and post-task measures included maximal voluntary isometric contractions (MVIC), and voluntary activation and contractile properties of the plantar flexor muscles, assessed using peripheral electrical stimulation of the tibial nerve. Surface electromyography was recorded for the medial and lateral gastrocnemius, soleus, and anterior tibialis muscles.<h4>Results</h4>The SLHR resulted in 20.5% reductions in MVIC torque (p<0.001). However, the number of SLHR repetitions was not correlated with either the baseline MVIC (maximal strength; p = 0.979) or the reduction in MVIC following the SLHR (p = 0.23). There were no sex differences in either the number of SLHR repetitions (p = 0.14), baseline MVIC torque (p = 0.198), or the reduction of MVIC (p = 0.14). MVIC decline was positively associated with the reduction in voluntary activation (r = 0.841, p<0.001), but was not associated with the change in twitch amplitude (p = 0.597).<h4>Conclusions</h4>The SLHR was similar in young males and females yet was a poor predictor of maximal plantar flexor strength but evaluates performance fatigability of the lower extremity specific to dynamic contractions. The reduction in maximal strength at task failure was explained by reduced neural drive to the plantar flexor muscles in both males and females.<h4>Impact statement</h4>SLHR performance is not a clinical assessment of plantar flexor strength but assesses dynamic lower extremity fatigability that is similar in males and females. Alternate clinical measures for maximal plantar flexion strength need to be developed.https://doi.org/10.1371/journal.pone.0253276
spellingShingle Lauren K Sara
Savannah B Gutsch
Sandra K Hunter
The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.
PLoS ONE
title The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.
title_full The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.
title_fullStr The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.
title_full_unstemmed The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.
title_short The single-leg heel raise does not predict maximal plantar flexion strength in healthy males and females.
title_sort single leg heel raise does not predict maximal plantar flexion strength in healthy males and females
url https://doi.org/10.1371/journal.pone.0253276
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