Radiotelemetric and strain gauge equipment in scientific research and sports practice.

Among the devices currently used for technology research sports movements, body reactions athletes for a certain load, strain gauge and radiotelemetry devices have proven themselves well... As part of this review, we will tell you about them, as well as other interesting developments VISTI and our foreign researchers...

1. VISTI Research Institute.
2. Electrical strain gauge.
3. Sports strain gauge equipment.

VISTI Research Institute.

Of course, when planning this article, we could not help but tell you about this organization, because its contribution to our domestic, sports science simply huge. FSUE "Research Institute of Sports Technical Products" VISTI in fact, it is the first and only narrowly focused state scientific center in Russia, accredited Ministry of Education and Science of the Russian Federation for the development of sports equipment, equipment and equipment, as well as referee information devices and specialized sports devices. Since the appearance of this structure in our country, and this happened over 65 years ago, sport and science are now united and inseparable. This research institution is essentially the flagship of not only the domestic but also the global sports industry. The lion's share of the innovations described in this section belongs to the authors and developers of this institute...

Electrical strain gauge.

The extensive experience accumulated by scientists in the use of electrical tensometry in technology is used by researchers in the field of sports to study the dynamics and structure of sports movements, the magnitude of the forces developed in static positions and in motion. In addition, using electrical strain gauge methods, the magnitude and characteristics of the distribution of forces applied at the points of support on gymnastic equipment, on a wrestling mat, and at the moment of hockey players throwing the puck are studied. Electrical strain gauges, depending on the type of sensing element that senses and converts the measured strain, are divided into:

1. active resistance strain gauges,
2. piezoelectric strain gauges,
3. inductive,
4. capacitive,
5. photovoltaic,
6. and others.

In sports research, the greatest application has been found strain gauges, in which the electrical resistance of the sensing element changes under the influence of the measured strain. Strain gauges have proven themselves to be accurate and reliable sensors. By gluing them onto a solid base, you can make multiple changes throughout the year.

Measurements are also carried out using strain gauges, assembled using a bridge or half-bridge circuit. The electrical signal is amplified and fed to the input of the receiving recording device - a light-beam oscilloscope, a millivoltmeter or milliammeter, an electronic oscilloscope.

Feature electrical strain measurements in sports is that, depending on the objectives of the study, it is necessary to select the base on which the sensors are glued. The basis can be metal plates, rods, beams, rings.

Methods and means of electrical tensometry are being improved every year and make it possible to study the most complex elements of sports technique and the dynamics of muscle contractions that are inaccessible to ordinary visual observation. The combination of a measuring circuit with computer devices and data input to a computer ensures high quality research and management of the educational and training process of athletes.

The sports literature provides schemes and methods of application electrical tensometry in various sports. Electrical tensometry is widely used in scientific research in the field of sports, but it has not yet found proper application in the practice of coaches. This method is most widely used when measuring the efforts developed by an athlete while performing sports exercises. In water skiing, a strain gauge device using industrial equipment has been developed to record the total dynamic characteristics of an athlete’s movements. The device consists of the following elements: a force meter, an elastic steel ring with strain gauges glued to it. Recording from the force-measuring element through an amplifier is made on a computer recorder. The force meter is hinged at one end to the rod, and the other to the towing halyard and is oriented towards horizontal deformations. Such a device makes it possible to obtain objective characteristics of the dynamic forces (in the range from 0 to 300 kg) of water skiers - ski jumpers, slalomists and figure skaters.

Sports strain gauge equipment.

VISTI has developed a two-component strain gauge platform using semiconductor strain gauges, which makes it possible to obtain an output signal voltage of 1 V. In this case, dynamograms can be recorded without DC amplifiers. The platform is a collapsible structure consisting of an inner and outer frame, between which four strain gauges are fixed. The vertical component is measured by semiconductor strain gauges glued to horizontal planes, and the horizontal component is measured by sensors glued to vertical planes.

Tensodynamometric installation force recording consists of a strain gauge measuring forces in three coordinates in space, a control panel, a light-beam oscilloscope, and a direct current source (6...9 V). The installation is assembled on foil strain gauges with an increased sensitivity coefficient, which made it possible to obtain a current in the measuring diagonal of the bridge up to 50...200 μA (usually a current of up to 15 μA is obtained). A current value above 50 μA is sufficient to drive the loop (galvanometer) of a light beam oscilloscope.

Radiotelemetry in sports used to study the activity of the cardiovascular system, respiratory organs, brain biocurrents, and skeletal muscles. In recent years, this method has become widespread in the study of sports movement techniques and rhythmic structure in cyclic and acyclic locomotion.

To record radio telemetry data, various classes of oscilloscopes with photographic devices are used, as well as magnetic recorders and pointer recorders. To obtain urgent information in the process of radiotelevision measurements, instruments are used that make it possible to visually monitor the nature of changes in the studied quantities. The recorded measurement results are deciphered and processed. The results of the processing performed are presented in the form of tables and graphs characterizing the dependence of the measured values ​​on time.

Widely used in the training process radiocardioleaders. The use of the latest electronic elements allows such devices to be manufactured in miniature form, which meets the specific requirements of sports research and training (low weight and size, self-sufficiency of power supply). At St. Petersburg University, our developers have designed a miniature autocardioleader with remote control. The device allows you to program your heart rate within 130…180 beats/min and telemetrically monitor physical activity at this frequency.

Autocardioleader It is characterized by high electrical and mechanical reliability, noise immunity and thermal stability. The device circuit uses integral and hybrid-film elements, which made it possible to create a device with minimal dimensions. Autocardioleader is used to optimize the training process of athletes in athletics, cycling, swimming, etc.

Currently, in the course of ongoing scientific research, systems have become widespread that simultaneously record various functions of the body and the musculoskeletal system. The Institute of Biological Instrumentation of Russia has developed a four-channel radiotelemetry system for medical and biological research of athletes. The equipment is designed for transmitting electrocardiograms, electromyograms, respiratory rate, and when using matching devices for transmitting sphygmograms and pulsograms. In practice, the systems’ devices mounted on the athlete’s body allow the transmission of any four signals in all available frequency ranges (Wi-Fi, Bluetoth, and others).

To register the main parameters of external respiration and ECG in the ergonomics laboratory of the Sverdlovsk Institute of National Economy, a two-channel radiotelemetry system. A miniature vane anemometer was used as a sensor. The meter is a magnetoelectric converter with permanent magnetization. The device uses combined carrier modulation. The ECG signal is transmitted using a dual frequency modulation system, and the respiratory complex information is superimposed on the subcarrier, modulating its amplitude. In the “breathing” block, minute volume and respiratory rate are recorded, in the “pulse” block - heart rate and total pulse value.

The ability to study and control the training process in natural conditions using radio telemetry equipment significantly complements comprehensive studies of athletes’ performance in laboratory conditions. Thus, radiotelemetry studies conducted on cyclists in racing conditions showed that during a race, heart rate ranges from 140 to 220 beats/min at a pedaling frequency of 60…120 rpm. When the pedaling frequency is reduced to 50...80 rpm, regardless of the route profile (flat, downhill, uphill) and gear ratio, the heart rate drops to 150...160 beats/min. It has been established that for highly skilled racers, the optimal pedaling pace of cyclists is within 90... 120 rpm at different gear ratios.

In running, important characteristics are the ratio of the support and flight phases. With increasing qualifications, the support time decreases to 0.08...0.1 s, which eloquently speaks of the high level of speed-strength qualities of the athlete. Studying the rhythmic structure of running based on the relationship between the support and flight phases is also possible using radio telemetry. Of particular interest is the registration of support-flight phases in running with simultaneous recording of ground reactions. This method, in particular, is used in the research of V. K. Balsevich. The method is based on the use strain gauge systems and teleelectrocardiograph. In this case, the transmitting device is a one-way communication line. The electrical impulses arising as a result of the imbalance of the bridge, reflecting the magnitude, nature and duration of the support reactions in running, are fed to the input of the frequency modulator of the pulse generator of the transmitting device. The signals from the transmitter are then sent to the receiver, amplified and recorded on an oscilloscope. Such a radiotelemetry system allows you to evaluate:

1. the nature, magnitude and duration of the vertical component of the pushing forces;
2. flight and reference interval times;
3. pace, running speed;
4. rhythm of locomotor movements.

To record the support-flight phases of running, you can use equipment created on the basis of the commercially produced “Sport-4” system with the connection of digital meters of time intervals with further data processing on a high-speed digital device.

It should be said that in recent years, issues of development and application technical means in sports are increasingly of interest to specialists and workers involved in the field of physical education and sports. At the same time, a significant part of the devices have yet to be created in single copies, which undoubtedly complicates their widespread introduction into sports practice. In addition, information about the created technical means and methods of their application is not systematized and is often inaccessible to practitioners. All this significantly hinders the qualitative improvement and improvement of the educational and training process and physical education.

In this series of articles, the authors of the site “fitness and bodybuilding in Russian” set the task of filling and compensating to some extent this annoying gap. Our articles provide designs for simulators, instruments and training devices that can be used not only in fitness And bodybuilding, but also in other various sports disciplines, both in the training of qualified athletes and a wide range of lovers of physical education and sports.