EMG amplitude and frequency parameters of muscular activity: effect of resistance training based on electromyographic fatigue threshold.

The present study aimed to evaluate the effect of a resistance training program based on the electromyographic fatigue threshold (EMG(FT), defined as the highest exercise intensity performed without EMG alterations), on the EMG amplitude (root mean square, RMS) and frequency (median frequency, MF) values for biceps brachii (BB), brachioradialis (BR), triceps brachii (TB) and multifidus (MT). Twenty healthy male subjects, (training group [TG], n=10; control group [CG], n=10), firstly performed isometric contractions, and after this, dynamic biceps curl at four different loads to determine the EMG(FT). The TG training program used the BB EMG(FT) value (8 weeks, 2 sessions/week, 3 exhaustive bouts/session, 2 min rest between bouts). No significant differences were found for the isometric force after the training. The linear regression slopes of the RMS with time during the biceps curl presented significant decrease after training for the BB, BR and TB muscles. For the MT muscle, the slope and MF intercept values changed with training. The training program based on the EMG(FT) influenced EMG the amplitude more than EMG frequency, possibly related to the recruitment patterns of the muscles, although the trunk extensor muscles presented changes in the frequency parameter, showing adaptation to the training program.

[1]  F. Felici,et al.  Electromyogram changes during sustained contraction after resistance training in women in their 3rd and 8th decades , 2000, European Journal of Applied Physiology.

[2]  E. Hoffman,et al.  Variability in muscle size and strength gain after unilateral resistance training. , 2005, Medicine and science in sports and exercise.

[3]  P. Komi,et al.  Motor unit activation patterns during isometric, concentric and eccentric actions at different force levels. , 2003, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[4]  Adalgiso Coscrato Cardozo.  PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIAS DA MOTRICIDADE ÁREA DE BIODINÂMICA DA MOTRICIDADE HUMANA ANÁLISE DE PARÂMETROS ELETROMIOGRÁFICOS DURANTE TESTES DE CONTRAÇÕES ISOMÉTRICAS FATIGANTES E DO EFEITO DE UM TREINAMENTO DE RESISTÊNCIA DE CURTA DURAÇÃO , 2006 .

[5]  Roger M. Enoka,et al.  Neuromechanical basis of kinesiology , 1988 .

[6]  A. Mikesky,et al.  Neuromuscular adaptations following prepubescent strength training. , 1994, Medicine and science in sports and exercise.

[7]  Gerson Campos,et al.  Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones , 2002, European Journal of Applied Physiology.

[8]  Tudor O. Bompa,et al.  Serious Strength Training , 1998 .

[9]  T. Moritani,et al.  The relationship between anaerobic threshold and electromyographic fatigue threshold in college women , 2004, European Journal of Applied Physiology and Occupational Physiology.

[10]  M. Gonçalves,et al.  Exercício rosca bíceps: influência do tempo de execução e da intensidade da carga na atividade eletromiográfica de músculos lombares , 2006 .

[11]  A. Veicsteinas,et al.  Electromyogram and mechanomyogram changes in fresh and fatigued muscle during sustained contraction in men , 1998, European Journal of Applied Physiology and Occupational Physiology.

[12]  Alain Martin,et al.  Isokinetic elbow flexion and coactivation following eccentric training. , 1999, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[13]  M. Pousson,et al.  Velocity-specific training in elbow flexors , 1999, European Journal of Applied Physiology and Occupational Physiology.

[14]  C. Bono.  Low-back pain in athletes. , 2004, The Journal of bone and joint surgery. American volume.

[15]  Travis Triplett-McBride,et al.  Effect of resistance exercise volume and complexity on EMG, strength, and regional body composition , 2003, European Journal of Applied Physiology.

[16]  Todd M Manini,et al.  Derecruitment of the Lumbar Musculature With Fatiguing Trunk Extension Exercise , 2003, Spine.

[17]  T. Masuda,et al.  Changes in surface EMG parameters during static and dynamic fatiguing contractions. , 1999, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[18]  K. Kerschan,et al.  Effects of back extensor strength training versus balance training on postural control. , 2000, Medicine & Science in Sports & Exercise.

[19]  Beatrix Vereijken,et al.  Changes in agonist EMG activation level during MVC cannot explain early strength improvement , 2005, European Journal of Applied Physiology.

[20]  W. Sparrow,et al.  Practice effects on coordination and control, metabolic energy expenditure, and muscle activation. , 2002, Human movement science.

[21]  W. Forrest,et al.  Muscle fibre direction of longissimus, iliocostalis and multifidus: landmark-derived reference lines. , 1989, Journal of anatomy.

[22]  P. K. Nielsen,et al.  The muscular load on the lower back and shoulders due to lifting at different lifting heights and frequencies. , 1998, Applied ergonomics.

[23]  P. Komi.  Strength and Power in Sport , 1993 .

[24]  Carlo J. De Luca,et al.  The Use of Surface Electromyography in Biomechanics , 1997 .

[25]  S. Gandevia,et al.  Deep and Superficial Fibers of the Lumbar Multifidus Muscle Are Differentially Active During Voluntary Arm Movements , 2002, Spine.

[26]  T. Zachry,et al.  EMG sensor location: Does it influence the ability to detect differences in muscle contraction conditions? , 2006, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[27]  Rieko Osu,et al.  Short- and long-term changes in joint co-contraction associated with motor learning as revealed from surface EMG. , 2002, Journal of neurophysiology.

[28]  P. Pattany,et al.  Muscle fiber hypertrophy, hyperplasia, and capillary density in college men after resistance training. , 1996, Journal of applied physiology.

[29]  L. Arendt-Nielsen,et al.  The effect of muscle pain on elbow flexion and coactivation tasks , 2004, Experimental Brain Research.

[30]  Ilkka Kuorinka,et al.  Restitution of EMG spectrum after muscular fatigue , 2004, European Journal of Applied Physiology and Occupational Physiology.

[31]  T. Housh,et al.  Electromyographic responses at the neuromuscular fatigue threshold. , 1995, The Journal of sports medicine and physical fitness.

[32]  A S C Oliveira,et al.  Electromyographic fatigue threshold of the biceps brachii muscle during dynamic contraction. , 2005, Electromyography and clinical neurophysiology.

[33]  A. Prochazka,et al.  Phasic activity in the human erector spinae during repetitive hand movements , 1997, The Journal of physiology.

[34]  Shi Zhou,et al.  Assessing Voluntary Muscle Activation with the Twitch Interpolation Technique , 2004, Sports medicine.

[35]  T Moritani,et al.  Determination of maximal power output at neuromuscular fatigue threshold. , 1993, Journal of applied physiology.

[36]  William J Kraemer,et al.  Fundamentals of resistance training: progression and exercise prescription. , 2004, Medicine and science in sports and exercise.

[37]  Jeffrey R Stout,et al.  Electromyographic fatigue thresholds of the superficial muscles of the quadriceps femoris , 2004, European Journal of Applied Physiology and Occupational Physiology.

[38]  M. Pozzo,et al.  Relationship between perceived exertion and mean power frequency of the EMG signal from the upper trapezius muscle during isometric shoulder elevation , 2005, European Journal of Applied Physiology.