Functional training

In 1956, following anatomical and sports medical analysis, Tittel wrote the textbook, Functional Anatomy [1]. For sports medicine and physical education, this was a milestone for the transfer of “systematic thinking and action in functions” from sports physiology to sports anatomy, that also had an effect on clinical medicine.

Functional thinking has attracted attention in clinical medicine, for example, via the International Classification of Functioning, Disability and Health (ICF), with the description of the interaction between damage to body structures and functions, the impairment of activities and participation and their contextual factors. With the growing use of equipment in medicine, orthopaedists, sports medicine specialists and manual medicine practitioners are reverting to a function-based perspective as, for example, in a basic model for the diagnosis and treatment of non-specific back pain [2].  

Functional Thinking

There has been a growing shift towards functional training in sports since the beginning of the century. This term introduces different training aspects specifically geared to the particular discipline of the athlete: use of body posture, body weight as resistance, training on unstable surfaces, specific targeting of stabilising muscles, development of proprioceptive capacity. Training and treatment measures referred to as neurophysiological also underpin functional thinking. While not neglecting strength and technique training, the aim is to continuously train skills on a broader basis, for example when carrying out multidimensional movements [3]. In general, “functional training is often defined as training that seeks to integrate the situational needs and limitations of real activities into the training environment in order to improve the effectiveness of the training” [4]. “Sports scientists and trainers should implement long-term training strategies that promote maximum muscle strength in the required context of the particular sport/event” [5]. Physiologically, this means speci­fically developing muscle strength in sensorimotor patterns typical for the particular sport. Functional training seeks to take the process of developing motor skills to the next level. This process needs to be shortened and made controllable and adaptable within the limits of specific time intervals in order to establish scientifically sound prognoses and to allow a better resolution of knowledge-based training tasks. In other words, it is about developing a technology to work out an “internal motor model” that ensures a noticeable acceleration of the motor learning process. 

The sportärztezeitung has already published a presentation of the functional system of behaviour (P. K. Anochin) [5, 6] as a cyclical sensorimotor feedback loop, with an emphasis on the reafference of the targeted movement outcome to the CNS and with the programme-forming and controlling units of the CNS [7] that can also be seen as a cybernetic model for the refinement of skills and capacities, as it combines the required control and feedback loops with one another (03/19 issue) [8]. This cybernetic approach first developed in physics and technology has now been transferred to biological and physiological functions and their optimisation and/or disorder. This makes it possible, indeed necessary, for the training researcher to analyse, present and implement into functional training the individual components in the motor system – feedback loops, sensors, regulators, actuators, effectors – as well as the type of information transmission (nerve impulses, messenger substances) and the movement parameters for optimising and expanding the control of the sports-specific motor patterns that determine performance.

Structures, Processes, States and outcomes

In a biocybernetic training model, movement is understood as the sensorimotor control and adaptation of the motor system in the centre of action outcomes. The motor system is under­stood to be all those structures, processes, states and outcomes associated with movement and posture [9]. The motor system generates reflex, rhythmical and voluntary movements that are highly individual. People can be recognised by their typical movements: gait, writing, musical identity of a violinist, elegance of a female gymnast. Functional training means also making active use of the individuality of the motor system to develop high performance. Normally, an athlete’s performance is characte­rised on the basis of their conditional and coordinative capacities. In most cases, it is the conditional rather than the coordinative capacities that are used to control training as they are considered to be readily measurable. The generated reflex, rhythmical and voluntary movement/movement components are all also the basis of the conditional capacities of strength, speed (in functional terms, actually acceleration) and endurance; they are under the constant control of the central nervous system. 

Active movement in the form of motor performance uses all the physiological resources of our body into which all functions are integrated for execution and coordination. Physiologically, this results in an interaction between  a “resource space” and the “function space” (Fig. 1), the individual functions – solution of physiological tasks – proceeding on different levels from the micro (cells) to the macro (individual/society) and being interlinked in a hierarchy both at one level and across different levels. [10]

• The resource space is understood to be the processes involved in gas exchange, digestion and metabolism (phosphagen, aerobic, anaerobic)
• The motor function space consists of the sensorimotor system (incl. perception, motivation and memory)
• The resource space allows the degree of freedom in the function space to be expanded
• The function space expands the resource space quantitatively and qualitatively

From this we deduce:

• use of the function determines the structure (form/matrix),
• anything that can be controlled is available.

The regenerative and function-conditioning potencies in the structures of the sensorimotor system can be specifically activated by loading, resulting in the achievement of both performance-enhancing and therapeutic effects. Dose-­dependent and adapted to the individual development of coordinative-conditional capacities, function-oriented training measures can also be used to develop specific sports performance standards. Effective loading depends also in functional performance training on generating loads that can be readily dosed and controlled, particularly controlled coordination loading. The effect is based on the finding that sensorimotor systems are able to develop learning strategies in order to optimise their systemic behaviour task-specifically. In this way, both movement visualisation as an “instructive internal model” and the motor programme as an “operational internal model” are realised. The optimisation and development of muscular output is considered as fundamental to the successful performance of sports activities. Much research has been carried out into methods to improve output and how this can be applied to sports performance. One issue that makes it difficult to compare the various studies is the use of different dynamometric methods (isometric, isokinetic and isoinertial) to measure strength and power [12]. It is an acknowledged fact that isokinetic and isometric assessment have little in common with the accelerating/decelerating movement that is fundamental to any movement. Human movement inte­grates power and acceleration (speed), which is usually selected intuitively. The muscles have adapted physiologically to these different conditions and developed a range of different muscle fibres with different biochemical and contractile properties and with the related neural interconnections of spinal neuromodulation. Muscles and their sensorimotor control develop and adapt individually in accordance with their specific loading – with a resulting increase or decrease in performance.

Sensor-Equipped and computer-based test and training equipment (CTT)

Dosing in training regimes is rarely based on currently diagnosed conditional capacity. Little attention is paid to the functional adaptation process taking place behind the coordinative capacities associated with strength and speed training. While it is true that sports medicine-based training methods have sophisticated sports-specific concepts to increase conditional capacities, these are also often one-sidedly directed towards specific performance standards (jumping power, explosive power, power endurance, aerobic endurance, acrobatics). It is only in a few cases that functional training, recently also known as neurocentric training, is directed towards improving coordination and the sensory afferences involved. The response of the sensorimotor systems of the skeletal motor system to defined loadings of their functionality was tested and trained in the martial arts in the former East Germany. A prerequisite for the concepts described below was the close collaboration of the Biomechanics, Neurophysiology and Sports Medicine Departments, which all had research laboratories next to each other at the Performance Diagnostics Hall. The regular performance tests monitored not only energy performance parameters but also neurophysiological activation capacity parameters as the basis of coordinative performance. In this context, mental training was also developed for specific use in various technical sports. Sensor-equipped and computer-based test and training equipment (CTT) for defined sensorimotor loads was developed and built in Leipzig. With this equipment it was possible to specify the required training loads and simultaneously compare actual performance with that specified. The theoretical background to such training equipment is based on neurophysiological and cybernetic aspects of the loading and refinement of skeletal motor stimulation (SMS). This equipment system has continued to be developed up to the present day under clinical and both sports health and training methodological aspects into a cybernetic concept that is now known as biofeedback motor control. The concept realises and combines test and training equipment in one unit. Measurements are taken of conditional performance and coordinative capacities as a basis for the functional training programme that immediately follows based on these measurements and is directed at the refinement of motor control, but without neglecting the parameter of condition. Sometimes the equipment was built in such a way that it allowed the realisation of the required motor patterns, such as a simulated wrestling throw, also to be disrupted by unforeseen opposing forces, thus taking on the character of a combat robot. Here as well it is the aspect of the cognisance and the variability of the motor patterns that is at the forefront. This is an aspect that has also been transferred to military movement patterns (flight manoeuvres). The person training receives feedback via a monitor on the target parameters achieved and thus can continuously control and adapt their coordination performance, which simultaneously proceeds with and behind the conditional performance – the movement visualisation and motor programme are trained and consolidated. The equipment concept realises several components that complement one another (trunk, upper, lower extremities) and, compared with traditional fitness equipment, combine several of their components [11]. The biocybernetic concept provides targeted input with programmable equipment.  

The person training is given the input as an input function on a monitor, in the form of a jump function or as a sine function with variable amplitudes and frequencies. This “template function” is to be followed by the person training on the equipment as a dynamic change in their strength and acceleration. For this, they are shown their “subsequent function” (as measured by the relevant sensors in the equipment) on a monitor, allowing them to compare this to the “template function” and make the necessary changes to correct any deviations.” The evaluation of the difference between the specifi­cation and subsequent function allows objectively measurable parameters of the current coordinative capacity to be determined, which directly serve to objectify performance and control training. From a neurophysiological perspective, the afference for cognisance and for forming an engram of the motor pattern is generated via the input both as a kinematic model and as a neurophysiological matrix. 

Focus on the motor pattern with no mobile and earphones

Loading contains quantitatively energetic and qualitatively coordinative components which the trainer can provide in various forms and individually adapt via the equipment software depending on the target set and the specific design and composition of the individual target components. In functional strength training, the SMS to be trained and conditioned are subjected to readily reproducible loads. Note: “functional strength training should be organised on the principles of the motor learning process, as the intended modification of the motor behaviour of the SMS integrated into the training is the outcome of a motor learning process”. This is made possible by the standard performance features of the equipment system:

• generally unlimited design/programming of the exercise structure
• precise load dosing
• generation of readily reproducible loading profiles
• control of training via online biofeedback methods
• documentation and storage of the subject’s personal data
• display of outcomes, documentation and archiving
• assurance and control of the reproducibility of the loading structure.

A core element of the concept is inte­grating the conscious behaviour of the person training into the training movements, which is enforced on the cybernetically based equipment by the specification and, once adaptively trained, can be transferred to other training components. This means in reality that even with pure strength training and even explosive power training the focus should be fully on the precise sports-specific motor pattern, i.e. with no mobile and earphones. The conscious varying of the motor patterns increases the degree of freedom (conscious variability), since previous study results suggest that strength variables may be of major importance for the improvement of functional performance [11]. The many skills formulated in sports methodology ultimately depend on the refinement of coordinative performance, while not underestimating the mental and social aspects. The control and regulation processes underlying the well-established sports motor skills limit themselves in the course of the motor learning process to the lower neuronal centres of the hierarchically organised sensorimotor subsystems. Thus a stage of automated and unconscious execu­tion of the movement is reached, which, however, does not mean that it cannot be recalled into consciousness, e. g. in a conscious analysis after the execution of the movement. As the performance and loading levels of the energy and sensorimotor processes are subject to physiological fluctuations and/or are affected by mental processes and social relations and are reflected in them, it is essential to constantly reinforce the establishment of the internal model of the motor skill through cognisance – conscious execution. The more often and the more systematically, the better. This is perhaps comparable to endurance training where every now and again the person training stops training for the last ten minutes, in which case they might as well dispense with the whole training unit. Hence the requirement above  not to listen to music during strength training, as strength training should also be coordinative training that promotes the development of the internal motor model via awareness.  

Conclusions for clinical practice

A more pronounced system-theoretical approach to the refinement of conditional and coordinative capacities should also be risked in established strength and explosive power training regimes. Ultimately, cognisance of the movement and formation of the engram of the motor pattern also help reduce the risk of injury. The cybernetic approaches related to high performance training also fully apply to “conditioning” in health training and in rehabilitation, irrespective of age. More cybernetic thinking in elite sport should lead to the system-oriented design of training equipment and/or the greater integration of what is available. Last but not least, there should once again be more active research into coordinative capacities, as they underlie both the large (virtually infinite) number of skills and conditional capacities. Old, established parameters (tracking, tapping, tetanus fusion frequency, flicker fusion and much more besides) should be used again and new parameters for the objective demonstration of the individuality of sensory and motor function mentioned to begin with should be reviewed.

Dr. sc. nat. Georg Blümel from Leipzig (BfMC GmbH)  co-authored the article.

Literature

[1] Tittel K. (1956) Beschreibende und funktionelle Anatomie. G. Fischer; 2016 in 16. überarbeiteten Auflage Kiener-Verlag

[2] Liefring V. Vinzelberg S, Seidel B, Beyer L (2020) Von der Funktionsstörung zur Funktionserkrankung – Ein Modell als Grundlage für die Diagnostik und Therapie von Rückenschmerzen. Deutscher Ärzteverlag | OUP | Orthopädische und Unfallchirurgische Praxis | 2020; 9 (5)

[3] Boyle M (2012) Fortschritte im Funktionell Training. rita-Verlag München

[4]  Ives JC and Shelley GA. Psychophysics in functional strength and power training: Review and implementation framework. J Strength Cond Res 17: 177–186, 2003.

[5]  Suchomel TJ et al. (2016) The Importance of Muscular Strength in Athletic Performance. Sports Med DOI 10.1007/s40279-016-0486-0 

[6]  Anochin PK (Anokhin). 1964. Systemogenesis  as a general regulator of brain development. s.l.: Progress in brain research. Vol 9: 54 – 86, 1964.

[7] Anochin PK. 1967. Das funktionelle System als Grundlage der physiologischen Architektur des Verhaltensaktes. Abhandlungen aus dem Gebiet der Hirnforschung und Verhaltensphysiologie. Jena : Fischer, 1967.

[8] Beyer L. (2019) Funktionelle Reagibilität – Grundlage optimalen Trainings und hoher sportlicher Leistungen. sportärztezeitung 03/2019, 51 – 52

[9]  Bernstein NA (1956) Bewegungsphysiologie. JA Barth 

[10] Pol R, Hristovski R, Medina D, Balague N. 2019. From microscopic to macroscopic sports injuries. Applying the complex dynamic systems approach to sports medicine: a narrative review. Br J Sports Med. 2019, Bde. 53: 1214 – 1220 DOI 10.1136/bjsports-2016-097395.

[11] http://www.bfmc.info/eng/index.php?cs=1   (Abruf zuletzt 22.08.22)

[12] John Cronin J and Sleivert G   (2005) Challenges in Understanding the Influence of Maximal Power Training on Improving Athletic Performance. Sports Med 2005; 35 (3): 213 – 234 review article 0112-1642/05/0003-0213/$34.95/0  

Autoren

Prof. Dr. med. habil. Lothar Beyer

ist Facharzt für Physiologie mit Lehrauftrag an der Ernst-Abbe-Hochschule Jena. Er ist Herausgeber der Zeitschrift Manuelle Medizin.