e.new techniques · transport capacity of the circulatory system, there would be an advantage in...

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E. New Techniques

HEART RATE CONTROLLED ERGOMETRY

L. G. EKELUND, M.D.

Dept. of Clinical Physiology, Karolinska sjukhuset, S 104 01 Stockholm, Sweden.

ABSTRACT

The control system of an electrically braked ergometer (Elema corp.) has been changed in order to include thepossibility to obtain an arbitrarily chosen heart rate automatically. The control unit consists of a heart rate metertriggered by ECG and a servosystem which is constructed to give a smooth load and heart rate response and to hold thepresent heart rate within about ± 3 beats/min. There are analog signals for recording of the heart rate, load andintegrated load. The practical applications will be discussed and demonstrated.

Introduction

In ergometry some kind of mechanically orelectrically braked cycle is one of the best tools. Thereare a great number of different modes of using theergometer. For instance it can be used with asingle-level-load, a discontinuous series of increasingloads or a continuous series of increasing loads with anearly steady state at each level. In Sweden the stepwiseincreased test of the continuous type is the mostcommon and gives a very good opportunity to study ECGreactions and circulatory variables when investigatingpatients in whom coronary insufficiency and heartfailure is suspected. In such a test one chooses steps ofloads in relation to the patient's physical activity andcondition. Loads of 200, 400 and 600 kpm/min forfemales and 300, 600 and 900 kpm/min for men are

Fig. 1 illustrates the ordinary exercise test with stepwisecontinuous increasing loads with registration of the heart ratebetween 5-6 min at each load. These and the followingrecordings should be read from the right to the left.

standard loads for testing normal individuals (fig. 1).However, when a patient is retested after some kind oftreatment, it is found that the pulse rate at thepreselected loads differs from time to time when fixedloads are used. In this case it would be better to use aheart rate controlled ergometer with which specific heartrates could be selected. A patient could then be tested atthe same heart rate each time, for example 110, 130,150 and 170 beats/min. In this way one could comparethe ECG reaction at the same heart rate both before andafter some kind of treatment. Also in ordinary fitnesstesting when the work load giving a heart rate of 170beats/min (W170) is used as an index of the oxygentransport capacity of the circulatory system, therewould be an advantage in selecting the heart ratesinstead of having preselected work loads. In the ordinarypreselected load type of testing one has to inter- orextrapolate the heart rate to obtain the load which givesa heart rate of 170 beats/min.

My own special interest in heart rate controlledergometry is based on my studies of prolongedcontinuous exercise on a fixed load. Under theseconditions there is a continuous increase in heart ratefrom, for instance, 140 beats/min after 10 min exerciseto 170-180 beats/min after 60 min exercise. Thesechanges were found to reflect a decrease in strokevolume with an unchanged cardiac output. The increasein heart rate over a fixed period is a measure of theunsteady state condition, but one could also have aconstant heart rate and measure the correspondingdecrease in work load over a fixed period.

Another application is in metabolic studies whenexercise is often used. Heart rate is a good index of therelative stress of the exercise but with an ordinaryergometer one has to perform several pilot tests to getthe same heart rates for different individuals in order tohave them comparable with respect to the relative work

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load. In such cases there is no problem with the heartrate controlled ergometer.

I will now describe briefly the technical details. Thereare no special technical problems in building a controlunit, which changes the load in an electrically brakedergometer in response to a change in heart rate. Theproblems are of a biological type. One problem is thateach individual has his own response to a stepwiseincrease or decrease in load. To get the ideal response

one must, therefore, know each individual's responsecurve. Another problem is that some individuals have analinear response with a marked time delay. In the bicycledeveloped in co-operation with Elema-Schonander inSweden we have used a control unit which gives an error

signal to the servo motor proportional to the deviationin heart rate from the preselected heart rate and alsotakes into consideration the rate of increase in heartrate, i.e. the first derivate of heart rate (fig. 2). Thisinfluence of the rate of increase in heart rate differs bothfor different levels of heart rate and also for increases or

decreases in heart rate (fig. 3). After testing manyindividuals we have found a rather good optimization ofamplification, damping and so on, so that we can obtainthe preselected heart rate without a large overshoot inload and have a stable heart rate for prolonged periodsof time (fig. 4), within 2-3 beats/min.

Analogue signals for recording of work load and heartrate are available. The integrated work load, i.e. totalwork, is indicated on a counter and there is an outputfor recording of every 10th kpm.

With this ability to control the heart rate over a

prolonged period one can get work load curves withrespect to time, which slope indicates the possibility ofmaintaining a steady state. It is also very easy to produce

CLOCK DIAGRAM

Fig. 3. The values for the influence of the first derivate ofheartrate.

a standardized work test with preselected heart rates asmentioned earlier (fig. 5) and also to get reproducableheart rates in order to test the ECG reaction aftertreatment with beta-blocking substances for instance.

A heart rate controlled ergometer is also an excellentinstrument with which to train patients, if one wishes touse continuous exercise as a form of training. One canselect an appropriate level of heart rate for training, forinstance 140 beats/min, and have the patient work forhalf an hour 2-3 times a week. I have used the cycle totrain medical students at two different heart rates, 130and 160, for three half-time periods per week with a

significant increase in total work output after 6-8 weekstraining (fig. 6). This type of training is especiallysuitable for training patients with coronary insufficiencyor post-muocardial infarction patients, where one couldvery simply select a heart rate which is somewhat belowthe level which gives anginal pain or undesirable ECGreactions. At present I have only trained four patientswho have had cardiac infarctions, but my preliminaryimpression is very good. For instance one patient whowas trained at a heart rate of 140 beats/min, achieved anincrease of 30 per cent in total work output for 30 min.

When testing large populations, for example militaryconscripts, the time spent on the test is critical, and toobtain our ordinary fitness index (W1 70) one often

Fit I Block diaran over the heart rate controlled ergometer.

The rate of change In frequency which gives the samo error signalFrequency as a frequency deviation of U boatsQnb/at*/,in Rate of increase In frequency Rate of decrease in frequency

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Fig 4. Rwording from a 30 min exercise period.

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Fig. 5. Recording from an exercise test in the same individual asin fig. 1 but with preselected heart rates.

needs 18-24 min of exercise. One-load testing has severaldisadvantages and therefore I have used the heart ratecontrolled cycle to get a rapid value for the load whichgives 170 beats/min (fig. 7). The value after 8 min isidentical with the conventionally obtained value.However, it is important to stress that such a test is onlya fitness test which gives no opportunity to study ECGreactions and other variables.

To summarize, there are several valuable applicationsof a heart rate controlled ergometer:

Rapid fitness testing.Reproducable ECG studies during exercise whentesting the influence of a treatment.Metabolic studies during exercise.Bicycle training, especially in coronary patients.

Fig. 6. Recording from a subject exercising for 60 min at a heartrate of 150 beats/min. Lower load curve is obtained beforetraining with a total work output of 54160 kpm and the upperload curve after 8 weeks training with a total work output of68660 kpm.

LI.M

Fig. 7. Rapid fitness test with estimation of the work load giving a heart rate of 170 beats/min (WI o70, in this case 1450 kpm/min.



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APPLICATION OF CYBERNETICS TO SPORTS MEDICINE

A. F. MATESANZ, M.D., and M. A. GONZALES, M.D.

University of Madrid, Spain

ABSTRACT

Classification, system and phenomenology of data inserted in a theoretical pattern comprising Sport, Medicine andPhysical Education will be exposed considered as a mathematical science.

We give some ideas about the way of calculating an equation, its possible programming in an electronic computerand its practical applications to the different medical, education and sports levels.

The study is divided into the following items:-

1. Psycho-physical study of the individual.

2. Study of integrant parts of the equation.

3. Study of parameters of sport gesture.

4. Study of sports from the point of view of its biological application.

5. Sport selection.

6. Sport therapeutics.

7. Prevention of sport accident.

8. Programming in the IBM-7090 of the Calculation Centre of the University of Madrid.

9. Summary and conclusions.

La Educaci6n F 'sica, ciencia joven aun, resultatodav(a eminentemente empirica, fraccionada en cuantoa los resultados y aCn por coordinar en cuanto a suscomponentes.

Se tienen multiples datos y se hace necesarioclasificarlos, ordenarlos, insertarlos al fin en una teoriaamplia y general que abarque el desarrollo integral de lapersona humana, tanto en su aspecto fisico comoeducativo.

La ciencia ha alcanzado su plenitud, su nombrepropio de ciencia, cuando los fen6menos que estudia sepueden expresar matematicamente, es decir, se puedecrear un modelo mental isomorfo con la realidadexterior. Naturalmente es imposible Ilegar a esteisomorfismo de una manera perfecta, pero nos podemosir aproximando cada vez mas. Este es el verdaderoprogreso de la ciencia y la constante investigaci6n deprofesores y educadores, m6dicos, psicologos ypedagogos tiende a alcanzar esta meta.

La Educaci6n Fisica, como ciencia, dista mucho aunde esta meta. Ha de recorrerse un largo cami no. Quiza lomas dificil sea insertar tantos resultados parciales dentrode una teoria general que recoja todos los aspectos de

educaci6n integral del hombre. No debemos olvidar quetodo, circunstancias del EGO y del NO-EGO, influyen deuna manera u otra en todas las acciones humanas. Portanto en los resultados deportivos entran much (simosfactores que a veces nos parecen extranios y que sinembargo tienen decisiva importancia.

En el presente trabajo nos referimos sobre todo a losdeportes como capitulo integrante de la EducacionFisica y desde un punto de vista practico a la selecci6nterapeutico-deportiva, a traves de los datos morfologicosy funcionales de cada individuo.

La ticnica de los affos 70 ha dado al hombre nuevosmedios para la investigaci6n cientifica y despues nuevaposibilidad para una rapida solucion de complejosproblemas matematicos inherentes a la investigacionoperativa.

En la incesante sucesi6n de inventos ydescubrimientos, la compaufia del calculo electr6nico harevolucionado las tecnicas corrientes y las indicacionesde este medio autoritario han aumentado rapidamente.

La Medicina y la Biologia u'nicamente en los sectorescientificos y sus enlaces, dependen hoy en d(a, mas, de



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los nuevos sistemas de simulaci6n que permiten extraerde los complejos fen6menos naturales, los aspectos demayor relieve e inter6s tranformandos en t6rminosnum6ricos.

La teoria de Einstein afirmaba que la comprensi6n delos hechos naturales puede entenderse por medio deconstrucciones puramente matematicas. Los diversos ycomplejos problemas que manan de la union de estasciencias, hoy pueden ser resueltos por el auxilio de lascomputadoras o calculadores electronicos.

Tenemos por tanto, justificada la tentativa de acoplarlas tecnicas de la investigaci6n operativa, es precisamentela teorfa de los graficos y el sistema del PERT en elestudio de los temas inherentes a los problemas deldeporte, la que propone continuamente nuevos camposde investigaci6n frontal en la siempre intensa selecci6ndel cuerpo humano en el trabajo agon(stico.

La teorfa de los graficos se publico por primera vez enla memoria de Leonard Euler en el ano 1763, pudiendoser subdividida en dos direcciones,. una de caracterp referentemente te6oico-matematico y otrapreferentemente operativa. La segunda direcci6n es laque nos interesa en la investigacion operativa y vienecaracterizada en la linea maxima de la investigaci6n dealgoritmos o procedimiento de calculos hachos pararesolver en casos concretos y desde el punto de vistanumerico los varios problemas inherentes a aplicacionesdiversas.

Es preciso manejar centenares de datos, otras tantasvariables que pueden influir en los exitos o fracasosdeportivos, relacionarlos entre sf por medio de losresultados emphricos obtenidos y elaborar una ecuaci6nque nos de aunque sea de un modo aproximado lacapacidad deportiva de cada sujeto.

Hace unos anos esta labor, por ardua, compleja yextensa, era practicamente imposible realizarla. Hoygracias al desarrollo de las computadoras electr6nicas esposible y esperamos, aunque sea para un futuro no muylejano, alcanzar los frutos deseados. Hablar decomputadoras y selecci6n de portiva no es una utopfa, niganas de querer complicar lo facil, es simplemente lafacilidad de organizar la selecci6n deportiva en laEducaci6n F isica a d iferentes escales. Recordemos queen algunas naciones existe ya un diagn6stico medicodado por ordenadores electronicos. No olvidemos, sinembargo, que la maquina es una ayuda del hombre y es6ste el que tiene que dar la uiltima palabra. No se trata,pues, de eliminar al profesor o al medico en la Educaci6nFi'sica sino de proporcionarle un valioso instrumento detrabajo al poder manejar de una manera global muchosmas datos de cada persona.

N uestra finalidad, es pues, crear un modelo

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matematico que explique el complejo mundo de laselecci6n deportiva, programarlo en el centro de calculode la Universidad de Madrid e ir dando a conocer a lasociedad los resu ltados obten idos.

Esto sera una albor de equipo, y ya desde aquiqueremos dar entrada a Organismos Federativos,Pedagogos, Medicos, Psic6logos y todo tipo de EntidadesDeportivas en una labor funcional que comienza desdeestas lneas directrices del programa. Es una labor detodos, pues a todos nos debe preocupar el bienestarf sico de cada persona y como resultado el bienestar ysalud de las naciones y de la humanidad entera.

cLa teoria general de los deportes es una cienciamatematica? Nosotros nos atrevemos a decir que s;. Laestad'stica ya ha entrado en todas las ramas del saber.ZPor que en esta no?

Lo que pretendemos es muy sencillo de expresar, notanto de lograr. Es: "Buscar una ecuaci6n matematicaque nos relacione cada deporte con los datos personaleso variables deportivas de cada persona".

En adelante la ecuaci6n sera designada por:

D = f (xi x2 ...... xn).

donde D = Cada uno de los deportesCada uno de los indicesdeportivosCada uno de los indicesm6dico-deportivos, etc.

f= Funci6n de relaci6n entredeportes y datos.

X I, X2 xn = Datos personales o variablesdeportivas.

Con un ejemplo: El futbol Zcomo esta relacionadocon el peso, talla, velocidad, resistencia, reflejos,agilidad, coordinacion neuromuscular etc.? cNo seriaposible matematizar esta situaci6n? Es decir, a traves delos datos personales cno habra posibilidad de seleccionarpara este deporte a los mejores, en posibilidades en unconjunto de alumnos?

Alguien se preguntara: cEs posible tener en cuentatantas variables, manejar tantos datos, en una palabraIlegar a obtener esta ecuaci6n?

Nuestro prop6sito es dar algunas ideas de comocalcular la f6rmula D = f (x); su posible programaci6n enun ordenar y sus aplicaciones practicas a nivel local(Colegios, I nstitutos, Universidades), provincial, regionalo nacional.



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1 FUNCIONES DEPORT IVAS

Def: Liamaremos "funciones deportivas" cada uno delos deportes federados o reconocidosinternacionalmente.

A continuacion hacemos un esquema de clasificacionde los deportes:

CLASI FICACION

Desde el punto de vista pedagogico no todos tienen elmismo valor ni todos pueden ser practicados por todo elmundo. Quiza un programa piloto se podria hacerunicamente para los deportes que tienen posibilidad depracticarse por grandes masas. El esqui acuatico puedeser deporte muy interesante como m6tadoppara mejorarel equilibrio, adquirir flexibilidad, tener reflejos y fuerzamuscular, etc., pero no es asequible mas que a muycontadas personas. No todos tienen una motora nitampoco un mar o un lago cerca, ni apetece realizarsedurante todo el anio. En las variables deportivas hemossenialado y tenido en cuenta las condiciones econ6micasdel individuo. Hay muchfsimos deportes en los que eldinero juego tambien su parte.

En la ficha deportiva que hemos hecho se ha tenidotodo en cuenta. Vds. pueden senialar los factores ovariables deportivas que tal vez hemos pasado por alto.

Asf y desde un punto de vista meramente pedag'gico

escogemos:

En Atletismo:

Carreras de velocidadde mediode fondo

Con acepciones de vallas y campo a trav6s.

Saltos

Lanzamiento

de longitud

de alturade triplede p6rtigade peso

de jabalinade disco

MarchaBa loncesto-ma n ibasketBalonmano-balonmano alevinVoleybol-minivoleyEsgrima floreteEsquiFutbolGimnasia deportivaGolfH (picaHockey hierba y patines

Lucha-JudoNatacion-crowl, braza, espanda y "delfin"Saltos de trampolfnRemo-piraguismoRugbyTenisTenis de mesaTiro con arco

2 VARIABLES DEPORTIVAS

Def: Llamaremos "variable deportiva" cada uno delos factores que puede influir en el rendimiento de undeporte.

Como veremos el nuimero de variables puede serinfinito. Hemos intentado hacer una clasificaci6n de esasvariables. De seguro que no es completa, como no lo sonlos multiples test que en diferentes paises se vienenpracticando, pero que nos sirven para marcar la pauta deactuacion sistematica.

Condiciones antropometricas.Condiciones analfticasCondiciones fisiologicasValores en reposoCardiocirculatorioRespiratorioHematicoPruebas de esfuerzo.RuffierTuttleSchneiderHarvardMetabogramaCondicion motoraParametros de forma fisica.Resistencia y endurecimientoFlexibilidadFuerzaResistencia muscular localizadaP. habilidad motoraCoordinacion neuromuscularAgilidadTiempo de reaccionExplosionVelocidadCondici6n nerviosa y psicosensorialSexoEdad de iniciacionEdad de competici6nPlanificacion economicaI nstalacionesMaterialEstudio economicoAntes de los 6 anios



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de 6 a 88 a 1010 a 1212 a 1414 a 18Mas de 18madurezsenectud

La clasificaci6n anterior afecta a las cualidadeshumanas del individuo. Desde el punto de vistamatematico hacemos la siguiente clasificaci6n.

1) Variables lineales:

Son variables lineales las que en la ecuaci6n D = F (X)intervienen segun la primera potencia. La valoraci6n deesta cualidad depende de cada deporte.

Por ejemplo en el futbol la resistencia puede ser unavariables lineal.

2) Variables cuadraticas:

Son variable cuadraticas las que con la ecuaci6n D = F(X) intervienen segun la segunda potencia. La velocidaden el resultado de una carrera puede depender delcuadrado de la velocidad.

Esta classificacion desde el punto de vista de nuestrosfines es esencial. Nos permite de una manera global ver elvalor que puede tener ya la funci6n deporte.

El estudio de la influencia de cada variable en esaf6rmula ideal que tratamos de hallar sera trabajoespecifico de su intervenci6n en cada deporte. Serequiere un estudio profundo de cada unos de losfactores asi como du su interdependencia y correlacion.

Segun esta interdependencia podemos a su vezclasificar las variables asi:

1) Variables independientes.

Son aqueiias que practicamente no entranrelacionadas con otras en la ecuaci6n.

2) Variables correlacionadas.

Son aquellas variables que eztan intimamenterelacionadas con otras.

As; el peso y velocidad en las carreras, lacoordinacion y la agilidad con la resistencia en losdeportes de equipo.

El endurecimiento y la resistencia en las carreras defondo o larga distancia.

El la literatura deportiva son muy empleados losinidices. Estos son en realidad algunos de los monomiosde la ecuaci6n del deporte. Indices que por otra parterelacionan variables muy interdependientes. Para obtenerla ecuaci6n tendremos presente estos valores parcialesque se ha comprobado y experimentado muchas veces.Para nuestra ecuaci6n podemos calificar de 1 a 10puntos cada uno de las variables en las que no haya otramedida ya tradicional. Tal sucede en el peso, talla,dinam6metria, escapular, lumbar, de empuje, etc., quetiene una unidad conocida. En realidad cada variable esuna magnitud. Nuestra primera ocupaci6n sera elegir lamagnitud-Unidad mas adecuada para muestros fines."Las magnitudes desempenian un papel esencial en todaslas ciencias, hasta el punto que se podria bablar del gradode desarrollo de una ciencia por el grado de elaboracionalcanzado por su teoria de magnitudescorrespondientes". (P. Abellanas). Para nosotros elestudio de las variables deportivas constituye, pues elnucleo de la futura investigacion. Es necesario elaborarm6todos de medida adecuados para cada una de ellas conrelaci6n a cada uno de los deportes, y su realizacion debehacerse por especialistas. El medico, el psic6logo y elsoci6logo deben trabajar juntamente en las pruebas, enlas comprobaciones, en la valuacion de los resultados.

Todos los resultados con su puntacion se ponen en laFICHA ME DICO DEPORTIVA.

Los datos, luego se pasan a unas fichas perforadas, o acinta magnfica e incluso se pueden leer directamente poruna lectora 6tica. Estos son los m6todos corrientes paraintroducir datos en una computadora tendi6ndose aemplear sobre todo el ultimo por la economia quesupone en tiempo, en trabajo y tambien en errcres.

En la elaboracion del programa para el IBM setendran presente todas las ventajas e inconvenientes y laviabilidad de cada uno de los metodos.

3. UTILIDAD Y APLICACIONES.

Tenemos ya nuestra ficha deportiva, es decir, desde elpunto de la computadora nuestra tarjeta de datos.

Tenemos tambi6n nuestro programa. cPero que es loque vamos a obtener?. Los fines que nos hemospropuesto y que salen de la computadora comoresultados escritos son:

1) Clasificai6n de un conjunto de FICHASDEPORTIVAS segun sus posibilidades, dadas entanto por ciento, para cada uno de los deportes.Las fichas vienen ordenadas de mayor a menorcapacidad.

2) Dada una FICHA DEPORTIVA ordenar losdeportes, de mayor a menor segun la posibilidad



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y capacidad del individuo para su practica, encada uno de los parametros componentes.

3) Distribuci6n de los alumnos de los centros deensenianza media superior y laborales o bienclubs, grupos o entidades deportivas, seguincapacitacion para los deportes a trav6s de lasfichas de aptitud. El manejo de estos miles dedatos solo es posible en un ordenadorelectronico.

4) Dadas unas variables deportivas de un individuoindicar el deporte o los deportes que debenrealizar para alcanzar otras variables en el gradoque se indique.

Esto resulta de suma importancia cuando eldeporte se considera tambien como terapeuticaen el desarrollo organrico y arm6nico delhombre.

5) Dado un conjunto de individuos con unascaracter'sticas similares, indicar los deportes quedeben realizar o que mas conviene practicar.

6) Hallar los deportes ideales para un individuoideal. Me refiero en este apartado al hecho deque se puede fijar de antemano unas cualidadeso variables deportivas y ver que deporte esrecomendable en esta situaci6n por laexperiencia adquirada.

7) Fijado un rendimiento en un deporte y lasvariables naturales del individuo hallar laoptimizacion de las restantes para que se puedaalcanzar ese tope.

Este punto resulta sugestivo ya que el desarrollointegral del individuo es nuestra primera meta.

Complemento de lo anterior es lo siguiente:

8) Estudio de los deportes como indicacioneducativa habida cuenta de las condiciones detodo tipo en el ambiente y circuns tancias enque se pueden practicar.

9) Seleccion deportiva, al menos desde un puntode vista teorcico habida cuenta de que tendremosdatos de la capcidad maxima, de las mejores, enlos parametros necesarios para la realizacion delgesto deportivo.

10) Indicaciones especificas de los deportes comoterapdutica en aquellas personas que tengandisminuida parcialmente capcidades derealizaci6n, tanto como complemento, como deocupaci6n terapeutica de la actividad.

11) Y por ultimo, habida cuenta de los datos, sepuede organizar una autentica campana deprevencion del accidente y la enfermedad por eldeporte, pues de todos resulta conocido como elvencimiento no es solo factor de la oportunidadde realizaci6n sin6 de la capacidad mesurable,suficiente, prevista e integralmente programada.

Estos son los principales fines que la utilizaci6n de unprograma en el IBM nos alcanza. En posterior estudio deestas ideas de seguro que apareceran nueves aplicaciones,ya que el campo de una computadora es ilimitado ycapaz de manejar cientos de miles de datos en tiempominimo.

RADIO AID FOR COACHING A DEAF TENNIS PLAYER

Suzan LIVINGSTON and J. G. P. WILLIAMS, F.R.C.S.

Beaconsfield School of Lawn Tennis, Beaconsfield, Bucks.

ABSTRACT

Great difficulty has been experienced in coaching a good tennis player with a hearing loss of 100 decibals in eachear.

Use of radio aid "Russaid" has facilitated coaching very considerably, particularly after certain operating difficultieswere overcome.

The possibilities of this equipment in other countries is indicated.



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THE GRAPHICAL DISPLAY OF ANGULAR MOVEMENT OF THE BODY

P. R. CAVANAGH, B.Ed., Ph.D.,* and D. W. GRIEVE, M.Sc., Ph.D.

Royal Free Hospital School of Medicine, 8 Hunter Street, London, W. C. 1.* Present address: Biomechanic Laboratory, College of Health & Physical Education,

Pennsylvania State University, University Park, Pennsylvania 16802, U.S.A.

ABSTRACT

A display of recorded angular movements of the body should convey the temporal variations of posture at chosenjoints and the relationship between them. The information should be in quantitative form and it should be possible toeasily discern small changes in the patterns of movement with respect to angulation and timing. Photographicsequences, stick diagrams and angle-time diagrams partially meet these requirements.

This paper discusses an additional presentation of angular movement, the angle-angle diagram, which shows therelationship between two chosen angles throughout movement. Usually, but not necessarily, the angles refer to adjacentjoints or segments of the body. In locomotion, the shapes of the patterns obtained are sensitive to small changes ofperformance and have found application in the clinical examination of gait. It is likely that the angle-angle diagramwould be of value in the examination of movements in sport. Examples are given of patterns obtained from walking andrunning, stair climbing, box stepping, sit to stand movements and vertical jumping. The biomechanical purpose of thedisplay will affect the choice of type. The interpretation and usefulness of the angle-angle diagrams and the means ofobtaining them are discussed.

Introduction

The teaching and coaching of movement skills hasgrown up alongside the development of ci ne-filmtechniques. Cine-film and now closed circuit televisionprovide excellent means of recording movement, andthey have been welcomed by the coach in his difficulttask of communicating to his pupil. The recording allows

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him to relive the event in its original rhythm or to slowit down. Despite these technical advances, much slowerprogress has been made in the interpretation and meansof communicating what is to be seen on the screen.Although film contains all the information that might berequired it does not do what we would like it to, that isto emphasise the things that we should be looking at. Wemust be very gifted, even in very simple movements, toperceive the coordinated actions involved. The desiredemphasis is usually obtained by making a series oftracings from the film or by constructing stick diagramswhich highlight the required details of posture.Unfortunately the eye is insensitive to differences ofmovement patterns shown in stick figures, and the stickfigures cannot be read quantitatively. This method ofcommunication is simply inadequate for the purpose andwe must think of an alternative approach.

What is needed is a diagram whose shape is sensitiveto details of the movement, which can be judgedqualitatively or quantitively, depending upon the user.At one level, the shape itself could be used by the coachas an indication of good or bad performance, while atanother level the same diagram would convey accuratequantitative information for further analysis. A commongraphical approach is to measure the limb angles fromfilm and plot them against time, as is done in diagrams Aand B of figure 1 which describe walking. Cycle timefrom heel strike is plotted along the x-axis and degreesof rotation in the sagittal plane are plotted along they-axis. We can follow from these graphs the time courseof the thigh angle and knee angle. It is difficult to obtaininformation from the diagram about the coordinated

0 10TIME (per cent

cycle)

--a6%0-



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movements of the limb as a whole and to visualise itsposture. Figure 1 A describes the pattern of movementof someone walking very slowly. When we walk faster,the movements at the thigh and knee change both inamplitude and in their relation to each other. The newpattern is recorded in figure 1 B. Substantial differencesexist between the patterns of movement but the eye isnot very sensitive to the important differences betweenthem. Diagrams A and B in figure 1 emphasise (onecould say overemphasise) the relationships of theseparate joint movements to time. We think that adiagram which emphasises the relationship of the jointmovements to each other is a more suitable way ofpresenting the patterns of movement and is easier tointerpret.

-300

THIGH0 30

I

Instead of plotting an angle against time we plot itagainst another angle. This is usually, but notnecessarily, the angle of an adjacent limb segment. Weshall now develop a diagram in which the angle of thethigh to the vertical is plotted against the angle of theknee joint. Let us do so in easy stages before referringback to Figure 1. Figure 2 shows three positions of athigh. Points on a horizontal scale are used to representthe angle that the thigh makes with the vertical. Weadopt a convention that movement of the thigh in frontof the vertical is measured as a positive and movementbehind the vertical is measured as a negative angle.Incidentally, we are talking about the inclination of thethigh to the vertical and not the posture of the hip joint.Figure 3 shows three postures of a knee joint. The kneeangle is that between the long axis of the thigh and thelong axis of the shank. In Fig. 3, as in subsequent charts,we represent the knee angle on a vertical scale. Kneeangles of 9, 47 and 88 degrees have been represented.

Figure 4 shows a girl at four instants in a standingbroad jump. The two scales representing the thigh andknee angles are used as the axes of a chart that we callthe THIGH/KNEE diagram. A point on this chartrepresents both a thigh angle and a knee angle. Thepoints shown on the chart thus represent instantaneouspostures of the limb during the jump. Looking first atposture (a) at the beginning of the jump, the thigh angle

90

304

60 .

KNEE

of 22 degrees and knee angle of 46 degrees are plottedtogether at point (a) on the chart to represent theposture of the whole limb. Postures (b), (c) and (d) arerepresented by combinations of thigh and knee angles of(0, 61), (63, 54) and (1 1 1, 121) respectively. From thismovement only four distinct stages of the jump arerepresented on the THIGH/KNEE diagram. If all theintermediate stages had been included the curveobtained would tell us the complete pattern ofmovement of both the thigh and the knee throughoutthe jump. Thus we have a method of indicating bothposture and changes of posture in a compact form.

Now turn back to Figure 1. The THIGH/KNEEdiagrams (Figs. 1 C and 1 D) on the right contain thesame information as the ANGLE/TIME diagrams on theleft. The differences in the coordinated patterns ofmovement are more readily detected in the angle/anglediagrams. The thigh-knee diagrams are sensitive tochanges in the speed of walking. Figure 5 shows the



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THIGH20

ankle has to be considered. Figure 7 shows an0 ANKLE/KNEE diagram taken from walking. The knee

40 angle is represented in the same way as before. Kneeflexion moves a point on the graph downwards, kneeextension moves it upwards. We have replaced the thighangle on the X-axis by an ankle angle. An ankle angle of90 degrees is what you would get standing on the groundwith a vertical shank. Plantar flexion reduces this angleto the left of the diagram and dorsiflexion increases it tothe right. The heel strikes the ground at the pointmarked H. This is followed by a period of coordinatedknee flexion and slight plantar flexion at the ankle. Thediagram moves downwards and to the left. Singlesupport then begins. The diagram moves upwards and tothe right, indicating that the knee is extending whiledorsiflexion is taking place. Plantar flexion then occursand the knee flexes. At toe off, shown as T on thediagram, the knee continues to flex. As the limb curlsup, the ankle is dorsiflexed to clear the toes from theground and the knee extends through to heel strike.

It is very difficult to make interpretations of thisnature from movie film or from angle-time diagrams. Itis quite easy to see from the ankle/knee diagrams howthe coordination between knee and ankle changesdramatically with the speed of walking. It is worth

JL 057curves for five subjects walking at the same speed. Thegraphs contain all the angular data of the two limbsegments which can be read quantitatively. Alternativelya coach may find it adequate to work with the shapesalone, once he has familiarised himself with the patternsassociated with different types of performance. If wecompare the shape of this family of curves with thatfound in Figure 6 we see immediately that somethinghas happened to change the shape which means that thepattern of movement has changed. The new shape is acharacteristic one obtained when walking at a higherspeed. The loops are larger and more rounded. Fromthese diagrams it is easy to pick out the coordinatedactions of adjacent parts of the body. For example,reading the diagram anti-clockwise, the vertical descentof the curve from heel strike (top right) tells us that thethigh angle remains fixed while the knee flexes through20 degrees. We also see a coordinated straightening ofthe knee with extension of the thigh at the hip. Thesefeatures were absent at the low speeds of walking shownin Fig. 5. These two sets of thigh/knee diagrams coverthe same range of speeds as did the upper and lowerdiagrams in Fig. 1. The differences between the twopatterns of movement are much clearer in theangle-angle diagrams.

To complete the description of the lower limb, the

THIGH20

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noting that we have not sacrificed time information inangle-angle diagrams. The dots along the curve representthe time scale, in this case tenths of the total walkingcycle time. The double lines indicate periods of doublesupport.

We recently became interested in why race walkers asa group suffer from excessive shin pain. A possiblereason for this pain which ordinary fast walkers do notexperience is that the pre-tibial muscles are being usedexcessively. We obtained electromyographic evidencethat this was the case and then turned to angle-anglediagrams to see what mechanical insults were beingapplied to the muscle group. Figure 8 shows theTHIGH/KNEE and ANKLE/KNEE diagrams of ColinYoung, an International race walker, walking at topspeed. The international rules state that the leg must bestraight at some stage during contact with the ground.The diagram shows that the knee was indeed held

plantar ANKLE

60

dorS

straight for more than half of the stance phase, quiteunlike ordinary fast walking. This means that the impactof heel strike is transmitted to the ankle without kneecushioning. The ankle-knee diagram shows that theanterior tibial muscles which are active at this stage areforcibly stretched by 20 degrees of plantar flexion inthis period following heel strike.

4*-- THIGH -n

Let us now look at a different movement, stairclimbing, and show how additional information can bepresented on an angle-angle diagram. Figure 9 shows theTHIGH-KNEE diagram describing the pattern of

O movement involved in stair climbing. The dotted line11 shows the pattern of movement when ascending one

eight inch stair, the solid line the pattern for ascendingtwo eight inch stairs at a time. These patterns are seen tobe quite similar in character, two steps requiring only anincrease in the amounts of thigh and knee flexion. Thethird scale on this chart shows the angle of the shank to

T HIGH

KNEE

STAIR CLIMBING

T

.

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the vertical. The shank angle can be represented becauseit is a function solely of thigh angle and knee angle. Wecan read the shank angle obliquely on the scale at anystage in the movement. We see that after the toe strikesthe stair, there is a period of knee extension and thighextension. Reference to the third scale shows that thisknee extension occurs about an almost fixed shank, theshank moving only ten degrees while one hundreddegrees of knee extension if occurring. That is to say,the knee is fixed in space and we lever ourselves up overit. We can also see that the shank trails behind during theswing through, finally straightening twenty degrees forplacement. If we know the thigh and knee angles, we canwork out where the ankle is in space relative to the hipjoint. The user of the thigh-knee diagram has no need tomake this calculation because the information can beread directly from the diagram, as is shown in Fig. 10.

Agoie~d<__THIGH

133

during the movement in support, but also we see that ofall the possible ways of gaining height the chosen patternof movement achieves it in the most direct manner,cutting the lines of constant height perpendicularly.

In many movements in sport, the inertia of parts ofthe body affect performance. The inertia of the lowerlimb depends only upon the postures of the knee andankle. Figure 11 shows how the moment of inertia aboutthe hip can be read off directly from an ANKLE/KNEEdiagram. Such a diagram might show the coach how achange in the posture would affect the inertia. The ankleaxis appears as usual - plantar flexion to the left,dorsiflexion to the right, as does the knee axis withextension and flexion upwards and downwardsrespectively. But in addition we see the moment ofinertia of the swinging limb indicated by the linescrossing the diagram.

zIxy

l

WAK SWING PHASE RUWALK { a RUN

ANKLE

7901

9 -aX8 l

"I t-114~~~~~

ANKLE20 a

We see that flexing the knee decreases the inertia ofthe limb, as does dorsiflexing the foot. The twoexamples depict race walking and running. Theconsiderable extra reduction of inertia of the limb that isachieved in running is readily detected.

Gaining height in stair-climbing.

Suppose we wish to know the contributions that thethigh and knee make to the total gain of height duringthe stair climbing movement. Figure 10 is anotherthigh-knee diagram. In addition to the thigh and kneeaxes the chart contains lines of equal height of the hipabove the ankle calculated from anthropometric data.Any combination of thigh and knee angles along a 'lineof constant height' represents a particular reductionfrom the maximal vertical distance that is possiblebetween hip and ankle. Not only can we read off fromthis graph the fact that 22% of stature has been gained

The diagrams we have shown were all obtained fromthe rather tedious analysis of cine film. Television doesnot make this analysis any easier. The diagrams will beof real use when they can be obtained as quickly as atelevision recording. We envisage devices which willmeasure and display the required angles duringperformance of the movement. Electrogoniometers andpolarised light goniometers represent a first generationof such devices, although in many sporting movementsthe technical problems of recording have not beensolved. The angle-angle diagrams have proved to be acompact way of representing patterns of movement, andbecause they are sensitive to small changes in thepatterns of movement we think that they will be usefulin the study of movement in sport.

3



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THE PRESENT LIMITATIONS IN THE KNOWLEDGE OF THE BIOLOGYBOTH ULTRA STRUCTURAL AND FUNCTIONAL; BEFORE, DURING

AND AFTER EFFORT AT DIFFERENT RATES

LA DELIMITATION ACTUELLE DES CONNAISSANCES DE LA BIOLOGIEULTRASTRUCTURALLE ET FONCTIONNELLE - AVANT, PENDANT ET APRES

D'UNE GAMME D'INTENSITE D'EFFORT

R. 1UNId, P. GALLE, V. iUNI6 and J. P. BERRY

ABSTRACT

The authors state that the current method of studying samples prepared for electron microscopy which breaks upthe basic enzymes and iso enzyme systems. If these results are compared with those obtained by bio-physical analysisthis confirms and supports the idea that a false picture is built up of what really happens and artefacts are created.

We have compared the values by using the techniques of electron microscopy and biophysics. Those sectionspreserved by fixing at -14oC maintained the composition of tissues before, during and after effort at their full value.Sections prepared by current methods for ultra structure research show a complete absence of co-enzymes and theother factors operating at the atomic level.

Coupes de tissu d'epaisseur - 400 A pour lesrecherches ultrastructuralle, prepares par la techniqueactuelle, montre grace a nos analyses biophysiquescomparees, I'absence de tous les facteurs au niveauatomique (Ca, P. Mg, Zn, Cu et egalment K, Na, Cl,comme on peut voir sur les diapositives).

La Preparation du tissu en ce moment pour lesrecherches structuralles au microscope 6lectroniquechasse cofacteurs primordiales d'enzymes oud'isoenzymes provoquant des alterations profondes nonseulement au niveau moleculaire. Ces alterationsn'6pargne aucunement la structure intracellu laire: toutesles organites sont ateintes. La membrane cellulaire dansces conditions meme sil n'ai pas altere, ne peut avoir quel'aspect du sens unilateral-du milieu intracellulaire aumilieu extracellulaire dans sa fonction.

D'apres nos analyses biophysiques sur les coupes dutissu pour le microscope electronique, nous avons lesperturbations du milieu extracellulaire, lesquelles ne

facilitent pas les recherches, au contraire, deforment lesconditions biologiques d'etude de l'espace intercellulaire(des neurones).

La technique de la preparation des coupes, nonseulement que reduit I'aspect fonctionel d'ultrastructure,mais en meme temps, dans la meme proportion cr6ed'arte fact, sans tenir compte des consequence de laconversion des processus physicochimiques incopatiblesbiologiquement.

Nous avons compare les valeurs des techniques demicroscope electronique et de biophysique relationnelle(les coups 40 - 50 fois plus epais = - 27) par la recherchesimultane sur 1iy3 . Les coupes congelees immediatementin situ b > 1400C fixent et conservent les composants dutissu avant, pendant et apres 1'effort dans sa valeurintegrale. Les coupes de la preparation actuelle pour larecherche ultrastructuralle montre absence total descoenzymes et les autres effecteurs au niveau atomique.



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A NEW TECHNIQUE FOR OBJECTIVE EVALUATION OF MUSCULAR EFFORT DURING EXERCISE

RABINDRA NATH SEN*, R. H. HARDING & P. R. M. JONES

Department of Ergonomics & Cybernetics, University of Technology, Loughborough7, Leics.

*Visiting University Research Fellow on leave from Industrial PhysiologyDivision, Central Labour Institute, Sion, Bombay, India

ABSTRACT

In athletic activities it is desirable to have information about i) the extent to which different muscle groups of thebody take part, ii) the degree of improvement in a training programme, iii) the difference in the muscular efficiency indifferent individuals, iv) the effect of fatigue. The information from parameters such as heart rate, oxygenconsumption, biochemical substances in body fluids, etc., may be sufficient, but these are indirect measurements ofmuscular activity and have certain other disadvantages.

The action potentials of individual muscles, electromyograms (EMGs), directly reflect the qualitative aspect of themuscular activity. An attempt to obtain a quantitative picture by the integration of the surface recorded EMG afterfull-wave rectification involves a large number of electrodes with a corresponding number of channels and makes thetechnique unwieldy and unsuitable for use in the field.

A new technique to evaluate muscular activity of a particular region or different regions of the body by quantifyingthe EMG picked up'by several sets of bi-unipolar surface electrodes (i.e. one unipolar over flexors and another overextensors) after passing through a summing amplifier was tried on a group of subjects at different resting postures aswell as during exercise.

The results indicate that this technique could be used with advantage in athletic activities in addition to the methodsfor other physiological parameters.

SEQUENTIAL TIMING OF OVERHAND PATTERNS OF WOMEN ATHLETES

M. J. ADRIAN and M. L. ENBERG

Department of Physical Education for Women, Washington State University, Pullman, Washington 99163

ABSTRACT

Competitive badminton, volleyball and tennis players utilise overhand patterns which are considered similar innature. Coaches often relate one pattern to another and assume that the mastery of one pattern facilitates the learningof another. However, this assumption may be false and may lead to interference with the expert performance of theother patterns. Therefore, this investigation was conducted to identify similarities and differences within and amongcompetitive women players of three sports. One subject (DC) had competed on the intercollegiate level in all threesports. The second subject (KB) competed in tennis since childhood and the third subject (CH) was an internationalbadminton player.

All subjects were filmed at 730-775 frames per second, performing the badminton smash, tennis serve and overhandvolleyball serve. Subject DC's performance showed greater intra-individual differences than did the other subjects.Subject BC assumed the tennis slice serve pattern for all her strokes; whereas CH's patterns resembled her badmintonstro ke.

Two basic patterns were noted. One pattern involved a step forward followed by pelvic rotation and the classic"unwinding" sequences for force production. The other pattern introduced flexion in the anteroposterior plane, as ahip-trunk and/or knee-trunk action.

The results lead one to question whether the patterns resulted from individual structural difference, order of learningor whether, in fact, one pattern is better suited to the performance of a given skill.



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PRESENTING AN APPARATUS FOR HOLDING THE LOWER LIMBSSTEADY DURING X-RAY, TO CHECK AND MEASURE DISCREPANCIES

OF LIMBS AND PELVIS, AS WELL AS TO SUPPLY A STEADY,ACCURATE AND REPRODUCIBLE BASIS FOR LATERAL DEVIATIONS

OF THE VERTEBRAL COLUMN

A. DAL MONTE, M.D.

Cattedra di Medicina dello Sport dell'Universita di RomaC. 0. N./. - Istituto di Medicina dello Sport

ABSTRACT

The aim of this apparatus is to afford a standard method to X-ray the differences in length of lower limbs, of pelvicdiscrepancies, and to supply a steady, accurate and reproducible basis to assess lateral deviations of the vertebralcolumn.

These radiographic problems have been noted in hospitals as well, several instruments having been made. As regardssports medicine, standardizing radiographic data is even more important, because in most cases the phenomena to beevaluated are less obvious than in hospital patients. Hence, it is necessary to improve research techniques to be able toevaluate them.

The apparatus that we made consists of a stiff and levelled platform. On it is a panel, fastened to a rotating axiswhich is placed between the lower limbs of the subject underexamination.The feet of the latter rest on two stiff boardsthat can slide vertically, by means of an electric elevator. The panel or baffle that is placed between the legs can bebrought up nearly to touch the perineum of the subject, by means of the vertical motion of the boards. Because of thevertical movement of the boards, very young children can also be evaluated.

By placing the subject astride on the baffle, and making the thighs and legs adhere to the stiff baffle, and by placingthe feet in the correct position on the footboards, we fix the geometric system with vertices at the two feet and the twocoxo-femoral joints. It is thus possible to achieve complete pelvic control.

In this way we do away with all postural adjustments that the subject with possible limb anomalies or deviations ofthe vertebral column, may have acquired in time.

X-rays of the pelvis and of the lower limbs, antero-posterior projection, makes it possible to measure exactly thedifferences in length of the limbs and pelvic discrepancies, as well as assessing accurately the degree of lateral deviationof the vertebral column.

Should the lower limbs differ in length, the exact range of the anomaly can be found out by raising the lower limbwith objects the thickness of which is known.

The apparatus can be caused to rotate on 3600, if it is necessary to make X-rays with lateral and oblique projections.



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e.new techniques · transport capacity of the circulatory system, there would be an advantage in...

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