Angle- and gender-specific quadriceps femoris muscle recruitment and knee extensor torque

Pincivero, Danny M.; Salfetnikov, Yuliya; Campy, Robert M.; Coelho, Alan J.

doi:10.1016/j.jbiomech.2004.02.005

Cited by 162 publications

(140 citation statements)

References 41 publications

(80 reference statements)

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“…With respect to the effects of RoM on EMG, motor unit recruitment is increasingly impaired as it reaches more extreme RoM positions (excessive flexion or extension), where EMG activity is decreased in order to protect the knee joint against high toque [4,7]. This …”

Section: Discussionmentioning

confidence: 99%

“…The optimized joint positions to produce torque are ~40-80° for knee extension [3][4][5] and 40-60° for knee flexion [4,5] (0° = full extension). However, existing literature presents some divergent results on maximal torque and joint positions: (1) the use of short RoMs (partitions of 15° to 30° throughout the full RoM) provides similar results compared to full RoM at low and moderate speeds, but also presents noteworthy inconsistencies [5,6], while (2) other studies have verified that the further from the optimized length-tension joint position, the lower the maximal torque [3,4,7].…”

Section: Introductionmentioning

confidence: 99%

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Maximal isokinetic peak torque and emg activity determined by shorter ranges of motion

Oliveira¹,

Corvino²,

Gonçalves³

et al. 2018

Hum Mov.

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Purpose. Isokinetic tests are often applied to assess muscular strength and EMG activity, however the specific ranges of motion used in testing (fully flexed or extended positions) might be constrictive and/or be painful for patients with injuries or undergoing rehabilitation. The aim of this study was to examine the effects of different ranges of motion (RoM) when determining maximal EMG during isokinetic knee flexion and extension with different types of contractions and velocities. Methods. Eighteen males had EMG activity recorded on the vastus lateralis, vastus medialis, semitendinosus and biceps femoris muscles during five maximal isokinetic concentric and eccentric contractions for the knee flexors and extensors at 60° · s -1 and 180° · s -1. The root mean square of EMG was calculated at three different ranges of motion: (1) a full range of motion (90°-20° [0° = full knee extension]); (2) a range of motion of 20° (between 60°-80° and 40°-60° for knee extension and flexion, respectively) and (3) at a 10° interval around the angle where peak torque is produced. EMG measurements were statistically analyzed (ANOVA) to test for the range of motion, contraction velocity and contraction speed effects. Coefficients of variation and Pearson's correlation coefficients were also calculated among the ranges of motion. Results. Predominantly similar (p > 0.05) and well-correlated EMG results (r > 0.7, p 0.001) were found among the ranges of motion. However, a lower coefficient of variation was found for the full range of motion, while the 10° interval around peak torque at 180° · s -1 had the highest coefficient, regardless of the type of contraction. Conclusions. Shorter ranges of motion at around the peak torque angle provides a reliable indicator when recording EMG activity during maximal isokinetic parameters. It may provide a safer alternative when testing patients with injuries or undergoing rehabilitation.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Maximal isokinetic peak torque and emg activity determined by shorter ranges of motion

Oliveira¹,

Corvino²,

Gonçalves³

et al. 2018

Hum Mov.

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“…The gender differences may have contributed to the difference in the activation of the EMG activity. Several studies have shown gender differences in various activities, such as greater strength of the knee extensor muscles 27 and in the contact and pressure area of the patellofemoral joint 28 in favor of the men. In contrast, the sliding and rolling between the femur and the tibia during the closed kinetic chain are greater in women 29 .…”

Section: Discussionmentioning

confidence: 99%

Análise do padrão eletromiográfico durante os agachamentos padrão e declinado

Fsm¹,

Fs²,

Chbf³

et al. 2009

Rev. bras. fisioter.

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Objective: To identify and compare the electromyographic (EMG) pattern of the main muscles of the lower limbs with bilateral support during standard and declined squats. Methods: Eight healthy subjects were recruited (three men and five women), all right-handed and weekend athletes (means: 20.57 years; 69.5±15kg; 1.73±0.15m). Electromyographic (EMG) signals from the vastus medialis obliquus (VMO), vastus lateralis (VL), biceps femoris (BF), soleus (SO), tibialis anterior (TA) and erector spinae (ES) muscles were recorded during the ascending (70º-0º) and descending (0º-70º) phases of the standard squat (horizontal plane) and declined squat (at 25º).The integral of the EMG activity for each muscle was calculated over an interval between 300 ms before the start of the movement and its end. The mean for each muscle for each subject was analyzed using analysis of variance for repeated measurements (ANOVA) to investigate the effect of the squatting task. Results: Qualitative analysis revealed that the muscle activity patterns during standard and declined squats were similar, and quantitative analysis did not reveal any differences in EMG activity. Conclusion: The results demonstrated that the EMG activity of the muscles studied was similar in these tasks.Key words: electromyography; knee joint; motor activity; exercise therapy. ResumoObjetivo: Identificar e comparar o padrão eletromiográfico (EMG) dos principais músculos do membro inferior com apoio bilateral durante o agachamento padrão e declinado. Métodos: Foram recrutados oito sujeitos (três homens e cinco mulheres), todos destros, atletas de final de semana e saudáveis (médias: 20,57 anos; 69,5±15kg; 1,73±0,15m). Foram registrados os sinais eletromiográficos dos músculos vasto medial oblíquo (VMO), vasto lateral (VL), bíceps femoral (BF), sóleo (SO), tibial anterior (TA) e eretor espinhal (EE) durante a fase ascendente (70º-0º) e descendente (0º-70º) dos agachamentos padrão (plano horizontal) e declinado (a 25º). A integral da atividade EMG de cada músculo foi calculada no intervalo de 300 milisegundos (ms) antes do início e do final do movimento. A média de cada músculo para cada sujeito foi analisada pelo teste de análise de variância para medidas repetidas (ANOVA) para verificar o efeito da tarefa de agachar. Resultados: A análise qualitativa revelou que o padrão de atividade muscular durante os agachamentos padrão e declinado foram similares, e a análise quantitativa não revelou diferenças na atividade EMG. Conclusão: Os resultados demonstram que a atividade EMG dos músculos estudados foi similar entre as tarefas propostas.Palavras-chave: eletromiografia; articulação do joelho; atividade motora; terapia por exercício.

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“…Some research has found that the EMG levels change with muscle length [68][69][70][71], while other studies indicate that joint angle has little effect on maximum EMG levels [72][73][74] or that there is no consistent pattern of change in the EMG levels with joint angle [74][75][76]. To address this potential problem, it has been recommended that maximum dynamic (usually isokinetic) contractions be used to obtain reference EMG levels in order to normalize EMG data obtained during movement [77].…”

Section: The Maximum Activation Obtained At a Range Of Joint Angles Umentioning

confidence: 99%

Normalization of EMG Signals: To Normalize or Not to Normalize and What to Normalize to?

Halaki¹,

Ginn²

2012

Computational Intelligence in Electromyography Analysis - A Perspective on Current Applications and Future Challenges

238

173

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Angle- and gender-specific quadriceps femoris muscle recruitment and knee extensor torque

Cited by 162 publications

References 41 publications

Maximal isokinetic peak torque and emg activity determined by shorter ranges of motion

Maximal isokinetic peak torque and emg activity determined by shorter ranges of motion

Análise do padrão eletromiográfico durante os agachamentos padrão e declinado

Normalization of EMG Signals: To Normalize or Not to Normalize and What to Normalize to?

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