Electromyography and muscle activity during exercise using Biopac

Electromyography BIOPAC Exercise Discussion

This discussion of the electromyography exercise will begin by first describing and discussing the exercise that was preformed. The results and corresponding data will then be contrasted with the original hypothesis. In this instance, the hypothesis created before initiating the experiment was shown to be supported by the data collected. Furthermore, the discussion will relate this exercise to other experiments that have been recently performed by members of the academic community in the field of medical research.

Experiment

The data collection in this laboratory exercise relied solely on the BIOPAC computer-based data acquisition and analysis system. This system includes all of the necessary equipment to detect electrical signals that are emitted by the skeletal muscular system. The sophistication of this equipment allows these signals to be recorded at the surface of the skin as opposed to other more intrusive methods of electrical detection in the human body. Another benefit this particular setup is that there is no need for calibration, the device automatically calibrates it sensors and the data recorded is automatically uploaded into the accompanying software.

This exercise was divided into two separate parts. In the first part, the test subject was asked to perform a routine of fist clenching, one hand at a time. When performing this routine, the device simultaneously recorded the electrical signals produced by the subject's body during these movements. The higher the number the device recorded equated to the greater amount of motor unit recruitment the subjects arm exhibited. The data was then sent to the software program for analysis.

In the second phase of this exercise, another variable was introduced to the experiment. An attachment to equipment, called a hand dynamometer, was added that recorded the force produced by the subjects arm during muscle contraction. Furthermore, the time frame that it took the clenched muscles to become fatigued was also recorded by equipment and automatically entered into the software program. These data was then analyzed to compare the differences in the electrical signals produced by both the dominant and non-dominant arms.

The hypothesis stated before performing the exercises predicted that the dominant arm would perform with greater electromyogram (EMG) readings while the subjects performed the physical tasks required of them. It also predicted that the dominant arm would be able to sustain muscle contraction for a greater amount of time than the non-dominant arm before reaching the point of muscle fatigue. The data collected supported both predictions of the hypothesis. The dominant hand, which can be intuitively considered the stronger of the two hands, was able to exert greater levels of electrical signals, greater force upon the hand dynamometer, and also required a greater amount of time before reaching a fatigued state.

The underlying physiology of the arm that further illustrates the chemical and mechanical processes that occurred during this experiment will also be described. The primary function of human muscles is to contract; thus giving the individual the ability to perform various movements and allow them a vast range of different motions. In order for this to occur the muscle must convert chemical energy (ATP) to mechanical energy. The trigger to initiate this process is provided by motor neurons. Each neuron is responsible for stimulating a specific group of muscle fibers which is also known as a motor unit. The body has a remarkable ability to match the amount of motor units stimulated with the amount of strength (contraction) required. When more force is required by the arm, more motor units are enlisted by the arm to help and this is referred to as motor unit recruitment.

EMG Testing Uses in Medicine and Research

One experiment conducted at the University of Tokyo, Japan, used a very similar equipment setup as the exercise described earlier in this discussion. The authors were trying to develop a system of estimating and indexing muscle fatigue rates during static muscle contraction. The results of this study indicated that estimations were reasonably successful with some limitations that were noted. One limitation was that the study neglected muscle recovery since the experiment was performed in a lab under controlled conditions and the muscles were able to fully recover. However, in the real world muscles move in a dynamic environment thus making muscle recovery rates a challenge in producing an accurate estimate of fatigue.

Another study looked at the efficacy of treatments in patients who suffer from Carpal Tunnel Syndrome (CTS). The study conducted research using 111 patients who suffer from CTS. They compared the standard conservative treatment (SCT) with other forms of treatment available that also propose to alleviate symptoms associated CTS. They found that SCT, which includes local steroid injections, was effective as a treatment. This study also used electromyopathy as part of a physical examination of the motor activity of these patients.

Another interesting research project used electromyography in order to gather data with prevention of wrist injuries in hairdressers in mind. This study used a portable data logger with EMG capabilities to monitor the movements of 21 hairstylists throughout the day. It found that the women in the experiment used more mechanical motion than the men in the group. The conclusion specified that there may be more of an ergonomic risk for females in the profession than there is for their male counterparts.

The final study considered in this discussion involves the feasibility of a new design for a prosthetic hand. Prosthesis is a very challenging research endeavor involving translating the neural responses produced by the body to understood by a mechanical device that can simulate human motion. Though this study goes into great depth about its data collection, the purpose of the study is to determine various ways in which this great feat may be overcome for amputees. The study once again used the signals collected in electromyography to provide the basis for further insights into how prosthetic hands may be developed to utilize the body's natural neural activity in order for the prosthetic devise to mimic natural human motion.