**3.1. Overview of muscle architecture**

Skeletal muscle architecture is defined in terms of "the arrangement of muscle fibers relative to the axis of force generation." The skeletal muscle arrangement as well as their activity reveals striking organization at the macroscopic level. The functional properties of the skeletal muscle depend strongly on their architecture [12].

There are various kinds of muscle fiber arrangements, which are discussed as follows:-

Computational Intelligence in Electromyography Analysis – 432 A Perspective on Current Applications and Future Challenges

**Figure 6.** The Delsys 2.1 Active EMG Electrode [11]

**3.1. Overview of muscle architecture** 

**3. EMG electrode placement and signal acquisition technique** 

subject, may effect a twitching sensation and cause him or her to make movements.

Surface EMG is relatively easy to use as compared to other EMG electrodes. This is the reason why it is being extensively used in the control of robotic mechanisms to achieve prosthesis. It is also widely used in latest EMG researches by engineers as no medical certification or expertise is required for its application. Its use in rehabilitation prosthesis is favorable as it does not cause any kind of discomfort to the subject on whom it is applied. Other kinds of EMG electrodes (needle and fine wire), when inserted into the skin of the

In order to get the best results from SEMG, it is really important to have a proper understanding of the muscles from which the EMG signal is being extracted. The placement on skin also requires adequate study and requires skin preparation beforehand as well.

The EMG electrodes, their types, sub-types and categories have already been explained in detail in the previous section. Since, our concern is only with Surface EMG (SEMG), hence, we will only deal with the placement and signal acquisition technique using surface EMG

Skeletal muscle architecture is defined in terms of "the arrangement of muscle fibers relative to the axis of force generation." The skeletal muscle arrangement as well as their activity

*2.3.2.2. Active EMG electrodes* 

electrode.

electrodes.

Electrodes shown in Figure 4 and Figure 5 both fall under passive surface EMG electrodes.

Active EMG electrodes contain a pre-amplifier attachment for surface electrodes. Needle and fine wire surface electrodes are also available. These electrodes usually fall under the dry surface EMG electrodes type. The in-house high impedance amplifier in these electrodes transfers the pre-amplified signal to the rest of the circuitry. Figure 6 shows an active EMG


A detailed depiction of these muscle arrangements is provided in Figure 7.

**Figure 7.** Muscles and their Architecture [13]
