Fatigue Consequences

The earliest onset of muscular fatigue affects the relaxation, not contraction rate of the muscle. The muscle fails to relax as rapidly as at first, with the result that the second stimulus may come before the effect of the first stimulus has been neutralized. The next effect of fatigue shows in the degree of contraction. The muscle contracts less and less to a stimulus of uniform intensity, which, if sufficiently prolonged, will finally result in absence of any contraction. Muscular fatigue is a chemical process, an accumulation of waste products (carbon dioxide^[1], lactic acid) in the muscle. The removal of these is normally done by the circulation. When the accumulation of waste products exceeds the rate of their removal and the rate of replenishing with efficient substances, fatigue sets in. If, before complete fatigue, a short rest period is allowed, the muscle shows a rapid recovery, since the waste products can be removed quickly, once activity ceases. However, if forced contraction be resorted to, when a muscle is already well fatigued, a much longer period of rest is needed for it to regain its contractility.

Muscular action, therefore, should not be carried on after moderate fatigue is present. In spite of popular opinion to the contrary, experiment has shown that fatigue in one set of muscles decreases the energy output of other sets. The flow of blood with its fatigue products accounts for this. Accordingly, the most efficient muscular activity is the first activity preceded by a moderate "warming-up" after relatively complete muscular rest. When we change from one hand to the other in piano practice, without complete rest periods, each successive attempt is muscularly less efficient . This, of course, is to be understood strictly physiologically. Improvement of coordination resulting through practice, readily outweighs the slight loss, if any, of muscular contractility. Moreover, unless the rate of muscular stimulation exceeds the rate of waste-product removal, no fatigue is present.
In normal piano practice, the pupil does not exceed the muscular fatigue limit, but probably never even reaches it provided the student applies the correct laws of piano technique. Sensations of fatigue are localized in the region of the affected muscles and not in the joints. The location of the fatigue sensations is thus an index to the muscle that has been active.

A pupil with whom I was working with for arm-relaxation, complained of fatigue in the deltoid muscle. Nothing in the outward movement of the arm had caused me to suspect arm-abduction. Once, however, this antagonistic muscular activity was revealed, she had no difficulty in relaxing. It is pedagogically advisable that each teacher become personally acquainted with the sensations resulting from muscular fatigue. This may be done in various ways. Prolonged activity in any unusual form, bowling or tennis, is a good example and will rapidly produce fatigue. If an ergograph is available, fatigue of any finger muscle can readily be recorded as well as felt . The sensation of fatigue, as we should expect, is not a sharp pain, but rather flat or diffused. It is, in consequence, often localized with difficulty by the young pupil who describes it as

"just generally tired",

"I feel it in my whole arm",

"I am unable to localize where it is."

An ergograph is a graph that shows a relation between human activities and a seasonal year. The name was coined by Dr. Arthur Geddes of the University of Edinburgh. It can either be a

1. polar coordinate (circular) or
2. a cartesian coordinate (rectangular) graph,

and either a line graph or a bar graph.

This graph of the climate of Weymouth over the cycle of the year is a cartesian form ergograph. In cartesian form, the X axis is marked for the months of the year, and the Y axis is marked with the scale(s) of the activity/activities. For example, in the ergograph to the right, the Y axis is marked with both temperature and rainfall/sunshine scales. In polar form, the months of the year are marked around the circumference, forming 30 ˚ sectors.
Concentric lines display the proportions of time (in hours per day) devoted to each of the activities. The time scale, ranging from 0 to 24 hours per day, is along the radius of the circle, and is a square root scale. This form of an ergograph is also known as a polar line graph or (because the data form "bands" on the graph) a

1. polar strata graph or
2. polar layer graph,

the "polar" denoting the system of polar coordinates used on the graph.
Ergographs can record human activities or agricultural/climate information, such as rainfall, temperature, humidity, crop types, and crop acreage.

1. Polar strata graph: A polar strata graph is a type of graph that is used to visualize the distribution of data over a circular area. It is similar to a pie chart, but instead of using wedges to represent the data, it uses layers. The layers are stacked on top of each other, with the innermost layer representing the smallest data value and the outermost layer representing the largest data value. Polar strata graphs are often used to visualize geological data, such as the distribution of different rock layers in a sedimentary basin. They can also be used to visualize other types of data, such as the distribution of different customer segments in a market.
Example of a polar strata graph:

2. Polar layer graph A polar layer graph is a type of graph that is used to visualize the distribution of data over a polar coordinate system. It is similar to a spider chart, but instead of using lines to connect the data points, it uses areas. The areas are filled in with different colors, with the darkest color representing the highest data value and the lightest color representing the lowest data value.
Polar layer graphs are often used to visualize financial data, such as the performance of different stocks or funds over time. They can also be used to visualize other types of data, such as the number of visitors to different websites on a given day.
Example of a polar layer graph:

Difference between polar strata graphs and polar layer graphs:
The main difference between polar strata graphs and polar layer graphs is in how they represent the data. Polar strata graphs use layers, while polar layer graphs use areas. This difference makes polar strata graphs more suitable for visualizing data that has a natural order, such as geological data. Polar layer graphs, on the other hand, are more suitable for visualizing data that does not have a natural order, such as financial data.

[1]: a colorless, odorless gas produced by burning carbon and organic compounds and by respiration. It is naturally present in air (about 0.03 percent) and is absorbed by plants in photosynthesis.