Document Type
Article
Publication Date
8-2021
Publisher
Public Library of Science (PLoS)
Source Publication
PLoS One
Source ISSN
1932-6203
Abstract
Introduction
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.
Methods
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.
Results
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).
Conclusions
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.
Impact statement
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.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Sara, Lauren K.; Gutsch, Savannah B.; and Hunter, Sandra K., "The Single-Leg Heel Raise does not Predict Maximal Plantar Flexion Strength in Healthy Males and Females" (2021). Exercise Science Faculty Research and Publications. 201.
https://epublications.marquette.edu/exsci_fac/201
Comments
Published version. PLoS One, Vol. 16, No. 8 (August 2021): e0253276. DOI. © 2021 Sara et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Used with permission.