New facts about hand control-kinaesthesia

Note originale

NEW FACTS ABOUT HAND CONTROL-KINAESTHESIA

E. M O B E R G

MOBERG

E. - - N e w facts a b o u t h a n d control-kinaesthesia.

Ann. Chir. Main,

1985, 4, no 1, 64-66.

M O B E R G E. - - D u n o u v e a u sur le c o n t r S l e et la k i n e s t h d s i e d e la m a i n . (En Anglais). Ann. Chir. Main, 1985, 4, n ° 1, 64-66.

S U M M A R Y : In the cases of major losses, kinaesthesia has to be evaluated in reconstructive arm and hand surgery if adequate functional results are to be obtained. Differing from earlier teaching, experimental work has shown that the dominating afferent receptor system for proprioception is located in the skin, not in joints or in the musculotendineous system. This fact must be taken in account in planning surgery as well as in the following (re-)education and training.

RI~SUMt~ : En cas de pertes majeures, il faut bien 6valuer le probl6me kinesth6sique si l'on veut obtenir de bons r6sultats en chirurgie reconstructive du membre sup6rieur et de la main. Contrairement ~ ce que l'on croyait autrefois, des travaux exp6rimentaux ont d6montr6 que le systSme proprioceptif pr6dominant rdcepteur-aff6rent est localis6 dans la peau, et non pas dans les articulations ou dans le syst6me musculo-tendineux. I1 faut en tenir compte dans la planification de la chirurgie ainsi que dans les programmes de r66ducation.

KEY-WORDS function.

MOTS-CLt~S : Main. - - Kinesth6sie. - motrice.

: Hand.

--

Controle-kinaesthesia. --

Motor-

In routine hand surgery kinaesthesia, the control of position, motion and effort is rarely a problem. H o w e v e r , when one has to deal with more important losses, as for example, in the case of cerebral p.alsy in children or in the aged, in serious plexus lesions and in the quadriplegic patient, this will be a major question. These patients have to use and to control grips which either have to be relearned or perhaps were never used before, and therefore, totally new to them. When new construction is the surgeon's only means of dealing with this problem with functional gain, this is exactly the case. It is at this m o m e n t that the problem of learning comes in. Control takes place at two separate levels, the conscious level and the computer level. All learning and training, as well as the decisions, must pass through the conscious level. However, when this is acheived, skill and speed are handled by the compuTerrassgatan 15, 41133 GOTEBORG (Sweden). Manuscrit requ a la Redaction le 3 mai 1984.

Contr61e. - - F o n c t i o n

ter level, even though these functions are, as Granit has said <~private to the muscles ,,. There are millions of afferent and efferent impulses which we are never aware of. T h e r e is, however, no time for conscious handling of such complicated mechanisms. We work with actions, not with single muscle contractions (fig. 1). T h e r e f o r e , kinaesthetic ( r e - ) e d u c a t i o n must go through the conscious level. As all motor functions are but a response, a <~feedback ~>,to afferent impulses, the question is : where are the receptors for the necessary afferent impulses located. Earlier, from 1890 to about twenty years ago, it was believed that they were located in the joints (Goldscheider). T h e n , advances in physiology changed this, owing to the extensive work on muscle spindles ; these and the Golgi apparatus in the tendons were claim e d to be the principal sites. A third possibility, that is the cutaneous receptors, were, if at all, just given a <~facilitating >> role. A number of clinical observations, however, have underlined the importance of cutaneous afferents

VOLUME4 NO1-- 1985

65

HAND CONTROL-KINAESTHESIA

Ecart moyen Pas d'anesthesie ............................................................... 3,4° Niveau d'anesthesie

£

L

~

..................... 17,5°

....................

Muscle ?

Articulation ? Tendon ? Skin ?

Ecart moyen Pas d'anesthesie ................................................................ 5° Niveau d'anesthesie

L

~

." ~:=.

Fig. 1. - - Where are the peripheral receptors for the afferents to conscious level located ? 1 = Conscious level. 2 = C o m p u t e r level. 3 = Efferent impulses 5 M / s e c . 4 = Afferent impulses 5 M / s e c . 5 = Skin. Fig, 2. - - In multiple and repeated tests on normal subjects it was determined with w h a t accuracy the subject actively put the t h u m b in an ordered position of varying flexion. Fig. 3. - - In tests similar to those in figure 2 the subject had to tell the position passively given to the proximal interphalangeal joint of the index by the experimenter. Fig. 4. - - Experimental arrangements in the Gelfan-Carter experiment, a = proximal level of anaesthesia. Obs : The fingers are in a s o m e w h a t flexed position. They are straight on the table the amplitude is almost used up and cutaneous factors come in as a source of error. Reprinted with permission, from Moberg E. [1]. Fig. 1. - - A quel endroit les recepteurs peripheriques pour les voies afferentes au niveau conscient se Iocalisent-ils ? 1 : Niveau conscient. 2 : Niveau de I'ordinateur. 3 : Impulsions efferentes, 5 M/sec. 4 : Impulsions afferentes, 5 M/sec. 5 : Peau. Fig. 2. - - Chez le sujet normal, des examens repetes, nombreux, ont ete necessaires pour determiner la precision avec laquelle il etait capable de mettre activement son pouce dans une position determinee de flexion. Fig. 3. - - Darts des examens similaires a ceux de la figure 2 le sujet doit preciser la position de I'articulation interphalangienne proximale de I'index, determinee passivement par I'examinateur. Fig. 4. - - Schema des experiences de Gelfan-Carter. a : Limite proximale de ranesthesie. Les doigts sont dans une position demi-flechie. Si les doigts sont etendus sur le plan de la table, I'amplitude s'epuise et les recepteurs cutanes entrainent une erreur dans les resultats de I'experimentation (reproduit avec I'autorisation d'E. Moberg [1]).

27,50

........................

25,7 °

.........................

27°

66

HAND CONTROL-KINAESTHES1A

and this is the basis of my study. There are no present day means of isolating the joint receptors in order to test them alone, but the fact that very good kinesthesia can be present in their absence, for example, in hips with total prosthesis, militates against their importance. The cutaneous and musculotendinous factors were therefore studied independently in the f o r e a r m and the hand of normal control subjects. Two different methods were used to separate the systems. First, extensive Cutaneous nerve blocking was performed at different;levels, leaving the musculotendinous system totally .intact. Active as well as passive digital m o v e m e n t s were studied, the former giving rise to skin moving over contracting muscles and tendons in motion. Although unable to move the skin, the passive movements provided the musculotendinous f a c t o r s necessary to signal the conscious level if they had the power to do so. The result was (fig. 2 and 3) that when the cutaneous receptor system was excluded u p to the level of the wrist, the thumb retained part of its proprioception due to signals arising from the skin moving over the tendons in the tabati6re a n d o v e r the muscle bellies higher up in the forearm.' It was only when anaesthesia had excluded all the cutaneous receptors up to the level of the elbow that appreciation of position disappeared. When, as in the tests with limited passive movem e n t s , no skin motion occurred higher up, this was enough to exclude the cutaneous afferents up to the level of the wrist with total loss of proprioception. The musculotendinous afferents from the forearm system were intact in the active as well as in the passive tests but failed to provide any information to the conscious level.

ANNALES DE CHIRURGIE DE LA MAIN

Secondly, the experiment devised by Gelfan and Carter (1967) was used, combined with the blocking technique. Flexor tendons were exposed at the wrist level under local anaesthesia, leaving the musculotendinous system intact (fig. 4). The exposed tendons could be pulled'out several centimeters without any reaction from the subject who was unable to perceive the elongation of the muscle or the tension in the tendon. This experiment has been widely discussed in the literature and has been claimed to be quite simple. As a result of our work in a large series, it was found to be true that the subject could not feel the elongation. However, when the tendon was pulled out a little further, so that the fascia and the skin at the proximal end of the muscle was moved, the cutaneous receptors were able to tell the subject what exactly was going on ! When this factor was blocked as well, the pull was no longer felt.

All these experiments clearly showed that no information reached the conscious level from the musculotendinous system. The cutaneous factor seems to be predominant. So far, it has been impossible to say just how much information comes from the joints and, obviously, the musculotendinous system has its importance on the computer level. There is no doubt that signals arising from the cutaneous system, once the narrow field of experimental conditions has been left behind, constitute an important but overlooked source of error in physiological research. The results show that in advanced reconstructive surgery, the building up of functions must be based mainly on the use of the cutaneous receptor system. As this system can readily be examined and moved to parts in need of proprioception, the practical consequences are obvious.

REFERENCE

MOBERGE. -- The roleof cutaneousafferents-inpositionsense, kinaesthesia, and motorfunctionsof the hand, Brain, 1983~106, 1,

Informations 5 e - CORSO PROPEDEUTICO ,, OF HAND SURGERY Savona (Italy), 7 / 1 3 July 1985 The Course will be held in the San Paolo Hospital of Savona under direction of R. Mantero. With a propedeutic aim, the programme will be concerning with the most interesting features of various hand pathologies, with regard to urgency and elective treatment : bone fractures and capsulo-ligamentous injuries, flexor and extensor tendons; surgery, plastic and neuro-vascular management, Rheumatoid arthritis, tumors and congenital malformations ; basic concepts about microsurgery and prostetic replacement wilt fournished ; particular effort will be done in illustrating the clinical and instru-

mental semeiotogy, and with practically showing the techniques of microscope, microosteosinthesis, physiotherapy and spiintage. For information write to: Segreteria del Corso, Sezione di chirurgia della mano, Ospedale San Paolo, 17100 SAVONA (Italy). Tel. : (019) 83121 (int. 442) from 8 a.m. to 13 p.m. 31" CONGRI~S DE LA SOCIET¢: INTERNATIONALE DE CHIRURGIE 31st CONGRESS OF THE iNTERNATIONAL SOCIETY OF SURGERY Paris, 1"r-6 septembre 1985 Inscription avant /e 16 aoOt 1985

Renseignements:Secr6tariat du Congres, PMV 31e Congres

SIC, 130, rue de Clignancourt, 75018 PARIS (France).