Discussion This lab explored the relationship between EMG and force and EMG and fatigue. It has been shown that EMG, fatigue and force levels are dependent upon type of contraction and whether or not the contraction is maximal or sub maximal. Seliger et al. (1980) gained insight into the differing force and EMG profiles of isometric, eccentric and concentric contractions. Fourteen subjects underwent a maximum voluntary contraction in the squat of the concentric, isometric and eccentric variations. He showed that the EMG activity in the rectus femoris showed little statistical difference. However the force reading showed its highest values during an eccentric contraction, it's lowest values during concentric contractions and its second highest values during isometric contractions (Seliger, 1980). EMG was shown to have a high correlation with it's MVC force output. When force …show more content…
For example if one subject's MVC is at 0.05V of BB activity while another's is 0.01V of BB activity, then you must normalize the data to their respective %'s of EMG during a MVC. At a specific % of submaximal EMG, you can compare between subjects, but not when considering absolute MVC. For example, when holding a 20lb dumbbell, one subject may only emit 0.04V of BB activity, and another subject would emit 0.03V of activity. For the first subject, this may be 70% of their MVC, and for the second subject this may be 100% of their MVC. If comparing between the absolute values of EMG, one would suggest the second subject is stronger, but at closer look, the first subject is stronger because they are using less muscle activity as a percent of their maximum EMG to lift the same load. Another method that is possible is to normalize to the maximal electrically stimulated muscle, which ensures all the motor units are
There are several different heart problems that show up as an abnormal EKG reading. For example, a heart block can occur when there is a delay in the signals coming from the SA node, AV node, or the Purkinje fibers. However, clinically the term heart block is used to refer to an AV block. This delays or completely stops communication between the atria and the ventricles. AV block is shown on the EKG as a delayed or prolonged PR interval. The P wave represents the activity in the atria, and the QRS complex represents ventricular activity. This is why the PR interval shows the signal delay from the AV node. There are three degrees of severity, and if the delay is greater than .2 seconds it is classified as first degree. Second degree is classified by several regularly spaced P waves before each QRS complex. Third degree can be shown by P waves that have no spacing relationship to the QRS complex. Another type of blockage is bundle branch block. This is caused by a blockage in the bundle of His, creating a delay in the electrical signals traveling down the bundle branches to reach the ventricles. This results in a slowed heart beat, or brachycardia. On an EKG reading this is shown as a prolonged QRS complex. A normal QRS is about .8-.12 seconds, and anything longer is considered bundle branch block. Another type of abnormal EKG reading is atrial fibrillation, when the atria contracts very quickly. On the EKG this is shown by no clear P waves, only many small fibrillating waves, and no PR interval to measure. This results in a rapid and irregular heartbeat. On the other hand, ventricular fibrillation is much more serious and can cause sudden death if not treated by electrical defibrillation.
Another weakness in the experimental design was that the reliability of the experiment was very low. As each test subject was only tested against each amount of prior exercise once, the impact of random errors is likely very large, which can be seen by the spread of the data on the graph. Although, this was attempted to be rectified by averaging the results of all four test subjects, it does not improve reliability too much. Conclusion: The results of this investigation indicated that a relationship between the amount of prior exercise and muscle fatigue does exist, however the results are also not conclusive enough to speculate on what the relationship is. This means that the hypothesis “If the amount of time spent performing vigorous exercise prior to the set of repetitions increases, then the physical performance (number of repetitions) will decrease” cannot be supported or rejected due to the inconclusive data.
The data was recorded for ten minutes. The last segment in the data collection was to analyze the effects of direct electrical stimulation. The hook electrode was disconnected and two electrode needles were inserted about five mm from each end of the gastrocnemius muscle. Starting at the maximum voltage from the first experiment, voltage was slowly increased until a twitch appeared. Then voltage was set to ten times the maximum voltage from the first experiment.
In this lab, we estimated the VO2 max for one subject on both the arm bike and treadmill. Estimating VO2 max is relevant because it allows the subject to compare their results with normal limits for their age and gender and see where they fall. It can also be used to make an exercise prescription in order to improve or keep a closer eye on your bodies own personal limits. Lastly, estimated VO2 max can be used as a diagnostic test to acquire information about a person’s health.
Purpose- To identify the functions of the cranial nerve of the peripheral nervous system such as the olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory, and the hypoglossal nerves. I will examine these functions with a series of behavior tests on my partner who is Jazmine Cooley to see if all nerves are functioning properly and if they are not, then this will be considered an identified dysfunction of a cranial nerve which is a diagnosis.
Kinesiology: The Mechanics & Pathomechanics of Human Movement (Second ed.). Glenside, Pennsylvania: Lippincott Williams & Wilkins. Qiao T, Liu C and Ran F. (2005) The impact of gastrocnemius muscle cell changes in chronic venous insufficiency. Eur J Vasc Endovase Surg 30; 430-436.
Cardiovascular Activity And How it Influences the body. Introduction: Cardiovascular fitness is a form of aerobic fitness (Neporent and Egan 1997). There are many different ways of evaluating the amount of oxygen used during cardiovascular fitness and one the methods involved is called VO2 Max. VO2 Max is the maximum amount of oxygen that the body can hold.
responses during prolonged treadmill walking with heavy load carriage. Medicine and Science in Sports and Exercise. 26:285-288.
Muscle fatigue is a decline in ability of a muscle to generate force within any part of the body. Muscular fatigue is a particular response when it comes to an untrained athlete that is starting an intense workout program, and the muscles of the body is not able to respond in an orderly manner as it would respond to an elite athlete. This paper will focus and provide general information about recent studies on peripheral fatigue. Peripheral fatigue is one of the sites for possible fatigue and its where neural, mechanical, or energetic events can hamper tension development. Neural fatigue is a factor of peripheral fatigue, which occurs when the nerves are unable to generate a signal and this reduces the ability of the muscle fiber to contract which is considered to be metabolic fatigue. Neural factors deals with the movement of action potential going through a process to produce a muscle contraction and when this process does not go through the proper steps then fatigue set in because the muscles will not be able to contract. Neural fatigue has two main factors which is, a shortage of...
The patient has been facing symptoms including increased thirst, frequent urination, unexplained weight loss, and fatigue. Having these symptoms causes his body to not be able to start cellular respiration, Electron Transport Chain, and the Krebs cycle. The patient's blood glucose level, intracellular glucose levels, and interstitial levels are out of range. The blood glucose levels normal range is between 78-108 mg/dL, but the patients is 130 mg/dL. High blood glucose levels makes your blood mucky. This slows down circulation which causes the cells to not get oxygen and the nutrients that they need. This also causes people to be fatigue. Since he is fatigue he is unable to do cellular respiration. As the cells run out of oxygen they change
For this experiment, it is important to be familiar with the diving reflex. The diving reflex is found in all mammals and is mainly focused with the preservation of oxygen. The diving reflex refers to an animal surviving underwater without oxygen. They survive longer underwater than on dry land. In order for animals to remain under water for a longer period of time, they use their stored oxygen, decrease oxygen consumption, use anaerobic metabolism, as well as aquatic respiration (Usenko 2017). As stated by Michael Panneton, the size of oxygen stores in animals will also limit aerobic dive capacity (Panneton 2013). The temperature of the water also plays a role. The colder the water is, the larger the diving reflex of oxygen.
This force transfers into the arteries and arterioles in other parts of the body as the blood moves away from the heart. Once the intensity drops and the stress on the heart decreases, the pressure in the arteries also reduces due to the less forceful contractions. Therefore, the hypotheses were accepted based on the averages of the data collected during the experiment. However, in order to have more accurate data, a larger sample size would be needed. In addition, using machines to measure heart rate and blood pressure could make the data more accurate than the process that was used in this experiment. Increased accuracy could also have been seen if there were more trials done when taking heart rate and blood pressure during the exercise stages and then averaging those
It can be stated that eccentric or concentric contractions can result in changes of a hamstring muscles length up to one third (Bennell et al., 1998). In sport discipline such as football hamstring injuries occur in a great degree during activities such as running or sprinting. This can be supported by the English FA which reported that in football movements such as running and sprinting stands for of 57% of all hamstring strains (Woods et al., 2004; Figure). During aforementioned activities the most common injury place is the bicep femoris along with the muscle tendon junction (Cross et al.,
AIM: - the aim of this experiment is to find out what the effects of exercise are on the heart rate. And to record these results in various formats. VARIABLES: - * Type of exercise * Duration of exercise * Intensity of exercise * Stage of respiration
This paper explores the various benefits and disadvantages of the use of Neuromuscular Electrical Stimulation (NMES). NMES has been used as a rehabilitation tool for many athletes who are recovering from various injuries and complications that arise in sports. NMES is a treatment that involves the use of a device called a muscle stimulator that transmits electrical impulses through electrodes that are applied to a specific muscle or muscle group. When this electrical impulse is applied to the muscle fibers, contractions occur and the muscle, shortens. NMES cause concentric contractions where the muscle shortens, but the individual receiving the treatment can go through exercises that also require eccentric muscle contractions where