TY - JOUR
T1 - Muscle activation during maximum voluntary contraction and m-wave related in healthy but not in injured conditions
T2 - Implications when normalizing electromyography
AU - Zellers, Jennifer A.
AU - Parker, Sheridan
AU - Marmon, Adam
AU - Grävare Silbernagel, K.
N1 - Funding Information:
This work was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number R21AR067390. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This research was also supported by the Foundation for Physical Therapy and the University of Delaware Research Foundation. The funding sources for this study had no role in the study design, collection, analysis, interpretation of data, writing, or submission of this manuscript.The authors report grant funding from the National Institutes of Health, Foundation for Physical Therapy, and University of Delaware Research Foundation for this study, but have no additional conflicts of interest.
Funding Information:
This work was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number R21AR067390 . The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This research was also supported by the Foundation for Physical Therapy and the University of Delaware Research Foundation. The funding sources for this study had no role in the study design, collection, analysis, interpretation of data, writing, or submission of this manuscript.
Funding Information:
The authors report grant funding from the National Institutes of Health , Foundation for Physical Therapy , and University of Delaware Research Foundation for this study, but have no additional conflicts of interest.
Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/10
Y1 - 2019/10
N2 - Background: Electromyography signal amplitude is influenced by a variety of factors. Normalization strategies aimed at decreasing signal variability include using peak electromyography signal during a maximum voluntary contraction and peak-to-peak M-wave amplitude. However, whether these normalization methods are comparable has not been investigated in injured populations. This study investigated the relationship between peak signal during maximum voluntary contraction and M-wave amplitude in individuals with a unilateral Achilles tendon rupture. Secondarily, we observed whether the two normalizations strategies would yield similar results when evaluating between limb differences in muscle activity during a jump task. Methods: Eleven individuals 1–3 years after a unilateral Achilles tendon rupture were included in this study. Surface electromyography was used on the medial and lateral gastrocnemii bilaterally. Peak maximum voluntary contraction, M-wave amplitude, and electromyography during a jumping task were collected. Findings: A strong relationship was observed between peak maximum voluntary contraction and M-wave amplitude on the uninjured (r = 0.71–0.88, P < 0.05) but not on the ruptured side (r = 0.41–0.44, P > 0.05). The two normalization techniques did not produce different results when comparing the uninjured and ruptured sides. Interpretation: The findings of this study suggest that M-wave normalization yields similar results as peak maximum voluntary contraction-normalized electromyography in uninjured conditions. M-wave normalization may be a useful strategy in an injured population where a maximal muscle contraction is unsafe or impaired.
AB - Background: Electromyography signal amplitude is influenced by a variety of factors. Normalization strategies aimed at decreasing signal variability include using peak electromyography signal during a maximum voluntary contraction and peak-to-peak M-wave amplitude. However, whether these normalization methods are comparable has not been investigated in injured populations. This study investigated the relationship between peak signal during maximum voluntary contraction and M-wave amplitude in individuals with a unilateral Achilles tendon rupture. Secondarily, we observed whether the two normalizations strategies would yield similar results when evaluating between limb differences in muscle activity during a jump task. Methods: Eleven individuals 1–3 years after a unilateral Achilles tendon rupture were included in this study. Surface electromyography was used on the medial and lateral gastrocnemii bilaterally. Peak maximum voluntary contraction, M-wave amplitude, and electromyography during a jumping task were collected. Findings: A strong relationship was observed between peak maximum voluntary contraction and M-wave amplitude on the uninjured (r = 0.71–0.88, P < 0.05) but not on the ruptured side (r = 0.41–0.44, P > 0.05). The two normalization techniques did not produce different results when comparing the uninjured and ruptured sides. Interpretation: The findings of this study suggest that M-wave normalization yields similar results as peak maximum voluntary contraction-normalized electromyography in uninjured conditions. M-wave normalization may be a useful strategy in an injured population where a maximal muscle contraction is unsafe or impaired.
KW - Achilles
KW - Inhibition
KW - Muscle
KW - Recruitment
KW - Rupture
UR - http://www.scopus.com/inward/record.url?scp=85069570801&partnerID=8YFLogxK
U2 - 10.1016/j.clinbiomech.2019.07.007
DO - 10.1016/j.clinbiomech.2019.07.007
M3 - Article
C2 - 31326725
AN - SCOPUS:85069570801
SN - 0268-0033
VL - 69
SP - 104
EP - 108
JO - Clinical Biomechanics
JF - Clinical Biomechanics
ER -