It is difficult to answer without knowing the done movement and the task's order.

For more information on EMG, you can go to http://www.seniam.org (Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles).

I also link some article to better understand neuromuscular fatigue.

http://www.ncbi.nlm.nih.gov/pubmed/?term=Bigland-Ritchie%2C+1981

http://www.ncbi.nlm.nih.gov/pubmed/12955870

Dear Selva,

A reference :

The Use of Surface Electromyography in BiomechanicsCarlo J. De LucaNeuroMuscular Research Center and Biomedical Engineering Dept. and Neurology Dept., Boston University

Abstract

The lecture will explore the various uses of Surface Electromyography in the field of Biomechanics. Three groups of applications are considered; those involving: 1) the activation timing of muscles, 2) the force/EMG signal relationship, and 3) the use of the EMG signal as a fatigue index. The discussion begins with a review of the technical considerations for recording the EMG signal with maximal fidelity and a compendium of all known factors which affect the information contained in the EMG signal. These relational effects are continuously analyzed throughout the discussion to assist in explaining the relevant concerns about the inferences that can be drawn from the analysis of the signal. Five cardinal questions are posed to guide the practitioner in the proper use of Surface Electromyography. Sixteen recommendations are made to provide assistance for the proper detection, analysis and interpretation of the EMG signal and measured force. Sixteen outstanding problems, which in my view, present the greatest challenges to the advancement of Surface Electromyography are put forward for consideration. Finally, a plea is made for arriving at an international agreement on procedures commonly in use in the fields of Electromyography and Biomechanics. 

A thesis of one of my students :

Incidence de l'entraînement en gymnastique sur le système neuromusculaire de l'enfant : étude comparative de paramètres mécaniques et électromyographiques chez l'enfant et l'adulte

renaud halin ·

12/2003, Degree: doctoral, Supervisor: germain philippe & bronnislaw kapitaniak

And two articles we have writen about this topic :

Neuromuscular Response of Young Boys Versus Men during Sustained Maximal Contraction

Renaud Halin · Philippe Germain · Stephane Bercier · Bronislaw Kapitaniak · Olivier Buttelli ·

Medicine & Science in Sports & Exercise 06/2003; 35(6):1042-8. DOI:10.1249/01.MSS.0000069407.02648.47 · 3.98 Impact Factor

Differences in strength and surface electromyogram characteristics between pre-pubertal gymnasts and untrained boys during brief and maintained maximal isometric voluntary contractions

Renaud Halin · Philippe Germain · Olivier Buttelli · Branislaw Kapitaniak ·

Arbeitsphysiologie 09/2002; 87(4-5):409-15. DOI:10.1007/s00421-002-0643-z · 2.19 Impact Factor.

Details in research Gate : philippe GERMAIN

We are open to a collaboration if you are interested by this topic.

Best regards

Philippe

Hi Selva

If you want to make sense of these, you will need to carefully explain the experiment, including: which muscle, electrode positioning, load level (fraction of maximal), duration of the exercise, level of pain felt by the volunteer, recording of the torque generated, details of the subjects, and more. My suggestion is that look at the SENIAM guildlines for this. If you are unsure, you may also see one of my pubs on this topic - in IEEE TNSRE in 2012.

Remember- the association of spectrum and fatigue is known, but weak. 

All the best