Muscle fiber conduction velocity and fractal dimension of EMG during fatiguing contraction of young and elderly active men

Boccia, Gennaro; Dardanello, Davide; Beretta-Piccoli, Matteo; Cescon, Corrado; Coratella, Giuseppe; Rinaldo, Nicoletta; Barbero, Marco; Lanza, Massimo; Schena, Federico; Rainoldi, Alberto

doi:10.1088/0967-3334/37/1/162

Cited by 44 publications

(37 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In agreement with previous findings from our laboratory [25,26], a significant positive correlation was found between FD and CV normalized slopes at 60% MVC in both genders. Considering that FD is less sensitive to changes in CV than other indices derived from the sEMG [22], we can assume that at higher level of contraction muscular fatigue may result of mutual interactions between central and peripheral mechanisms as previously hypothesized [69].…”

Section: Discussionsupporting

confidence: 93%

“…FD : As previously reported, an increase in MU synchronization may be observed during fatiguing isometric contractions at 25% MVC or higher [11,25,26,61–65]. …”

Section: Discussionsupporting

confidence: 51%

“…Indeed, Boccia and colleagues (2016) reported a steeper rate of change of FD in elderly males compared to young males during fatiguing contractions of the knee extensors suggesting a greater increase in motor unit synchronization with age [26]. …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Inter-Gender sEMG Evaluation of Central and Peripheral Fatigue in Biceps Brachii of Young Healthy Subjects

et al. 2016

Self Cite

View full text Add to dashboard Cite

PurposeThe purpose of the present study was to evaluate inter-arm and inter-gender differences in fractal dimension (FD) and conduction velocity (CV) obtained from multichannel surface electromyographic (sEMG) recordings during sustained fatiguing contractions of the biceps brachii.MethodsA total of 20 recreationally active males (24±6 years) and 18 recreationally active females (22±9 years) performed two isometric contractions at 120 degrees elbow joint angle: (1) at 20% maximal voluntary contraction (MVC) for 90 s, and (2) at 60% MVC until exhaustion the time to perform the task has been measured. Signals from sEMG were detected from the biceps brachii using bidimensional arrays of 64 electrodes and initial values and rate of change of CV and FD of the sEMG signal were calculated.ResultsNo difference between left and right sides and no statistically significant interaction effect of sides with gender were found for all parameters measured. A significant inter-gender difference was found for MVC (p<0.0001). Initial values of CV were higher in females than in males at both force levels (20% MCV: p<0.0001; 60% MCV: p<0.05) whereas a lower initial estimate of FD was observed in females compared to males (20% MCV: p<0.05; 60% MCV: p<0.0001). No difference in CV and FD slopes was found at 20% MVC between genders. At 60% MVC significantly lower CV and FD slopes (CV and FD: p<0.05) and a more protracted time to exhaustion were found in females than in males (p<0.0001). When considering time to exhaustion at both levels of contraction no difference in percentage change (Δ%) of CV and FD slopes was found between genders (p>0.05). During the sustained 60% MVC no statistical correlation was found between MVC and CV or FD initial estimates nor between MVC and CV or FD slopes both in males and females whereas. A significant positive correlation between CV and FD slopes was found in both genders (males: r = 0,61; females: r = 0,55).ConclusionsFatigue determines changes in FD and CV values in biceps brachii during sustained contractions at 60% MVC. In particular males show greater increase in the rate of change of CV and FD than females whereas no difference in percentage change of these sEMG descriptors of fatigue was found. A significant correlation between FD and CV slopes found in both genders highlights that central and peripheral myoelectric components of fatigue may interact during submaximal isometric contractions.

show abstract

Section: Discussionsupporting

confidence: 93%

“…FD : As previously reported, an increase in MU synchronization may be observed during fatiguing isometric contractions at 25% MVC or higher [11,25,26,61–65]. …”

Section: Discussionsupporting

confidence: 51%

See 1 more Smart Citation

Inter-Gender sEMG Evaluation of Central and Peripheral Fatigue in Biceps Brachii of Young Healthy Subjects

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Electromyography (EMC) data were also analyzed by fractal dimension analysis to determine the use of this methodology along with other parameters to better characterize the EMG signal, and to quantify motor unit recruitment patterns in biceps of normal patients [19,20]. Moreover, fractal analysis was used as a reliable measure of the skeletal muscle fatigue [11,12], and to assess changes in positron emission tomography (PET) data of peripheral vascular function of resting and exercising skeletal muscles [21]. Given the overall applicability of fractal analysis in myology, we emphasize the importance of this simple and low-cost methodology in translational medicine since it may be used as a differentiated tool for DMD diagnosis and disease staging.…”

Section: Discussionmentioning

confidence: 99%

Fractal dimension analysis reveals skeletal muscle disorganization in mdx mice

Cury

Freire

Martinucci

et al. 2018

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

Duchenne Muscular Dystrophy (DMD) is characterized by muscle extracellular matrix disorganization due to the increased collagen deposition leading to fibrosis that significantly exacerbates disease progression. Fractal dimension analysis is a method that quantifies tissue/cellular disorganization and characterizes complex structures. The first objective of the present study was use fractal analysis to evaluate extracellular matrix disorganization in mdx mice soleus muscle. Next, we mimic a hyper-proliferation of fibrogenic cells by co-culturing NIH3T3 fibroblasts and C2C12 myoblasts to test whether fibroblasts induce disorganization in myoblast arrangement. Here, we show mdx presented high skeletal muscle disorganization as revealed by fractal analysis. Similarly, this method revealed that myoblasts co-cultured with fibroblast also presented cellular arrangement disorganization. We also reanalyzed skeletal muscle microarrays transcriptomic data from mdx and DMD patients that revealed transcripts related to extracellular matrix organization. This analysis also identified Osteoglycin, which was validated as a potential regulator of ECM organization in mdx dystrophic muscles. Our results demonstrate that fractal dimension is useful tool for the analysis of skeletal muscle disorganization in DMD and also reveal a fibroblast-myoblast cross-talk that contributes to "in vitro" myoblast disarrangement.

show abstract

“…Decreases in FD may be considered as indicators of progressive MU synchronization [37], probably due to central fatigue (for review see [22]). We recently reported a decrease of FD during sustained isometric contractions of the quadriceps and biceps muscles, and these changes may be considered as an indicator of progressive MU synchronization [9,35]. Furthermore, FD showed a good reliability during isometric contractions in the biceps brachii muscle [7].…”

mentioning

confidence: 89%

Correlations Between Myoelectric and Hemodynamic Parameters Changes in Biceps Brachii During Sustained Isometric Contraction in Healthy Elderly

Zampella

Barbero

Cescon

et al. 2019

J. of SCI. IN SPORT AND EXERCISE

Self Cite

View full text Add to dashboard Cite

Purpose The purpose of the present study was to evaluate the Pearson correlations between hemodynamic parameters obtained with near infrared spectroscopy (NIRS), namely total hemoglobin (tHb) and tissue oxygen index (TOI %), as indicators of blood flow and oxygen extraction, and myoelectric parameters obtained with surface multichannel electromyography (sEMG), namely fractal dimension (FD) and conduction velocity (CV) slopes, as descriptors of central and peripheral fatigue, during sustained high level isometric contractions at 60% maximal voluntary contraction (MVC), in elderly subjects. Methods Ten recreationally healthy elderly subjects (age 67.7 ± 4.6 years), 5 males and 5 females, performed one isometric contraction of the elbow flexors at 120° joint angle at 60% of MVC until exhaustion in two subsequent trials 1 week apart, one for the sEMG and the other one for NIRS recordings from the biceps brachii. Results A negative strong Pearson's correlation between TOI % slope in the functional hyperemic phase (HP) of contraction and a positive correlation between the slope of TOI % recorded during the ischemic phase (IP) and the CV slope were found (r = − 0.76, P < 0.05; r = 0.91, P < 0.01, respectively). A negative strong correlation between tHb IP slope and tHb HP slope and TOI % IP slope and TOI % HP slope (r = − 0.78, P < 0.01; r = − 0.78, P < 0.01, respectively) were also found. No correlation was found between FD slope and hemodynamic parameters (FD slope vs. HP tHb slope, r = − 0.19; FD slope vs. IP tHb slope, r = 0.16; FD slope vs. HP TOI % slope, r = 0.19; FD slope vs. IP TOI % slope, r = 0.27). Conclusion In aged individuals, CV slope correlated with muscle O 2 desaturation (TOI %) rather than reduced muscle blood flow (tHb) in the ischemic phase of isometric contraction to exhaustion. No correlations were found between myoelectric manifestations of central fatigue (FD slope) and data obtained by NIRS.

show abstract

Muscle fiber conduction velocity and fractal dimension of EMG during fatiguing contraction of young and elderly active men

Cited by 44 publications

References 60 publications

Inter-Gender sEMG Evaluation of Central and Peripheral Fatigue in Biceps Brachii of Young Healthy Subjects

Inter-Gender sEMG Evaluation of Central and Peripheral Fatigue in Biceps Brachii of Young Healthy Subjects

Fractal dimension analysis reveals skeletal muscle disorganization in mdx mice

Correlations Between Myoelectric and Hemodynamic Parameters Changes in Biceps Brachii During Sustained Isometric Contraction in Healthy Elderly

Contact Info

Product

Resources

About