Rhythmic Stabilisation — a new approach

T he technique of rhythm ic stabilization as described by K n o tt “em ploys isom etric contraction of antagonistic and agonistic patterns, w hich results in co-contraction of antagonists if the isom etric contraction is not broken by the physical th erap ist” . (1) In order to obtain the desired co-contraction the therap ist m ust be extremely skilled and the p a tien t m ust exert considerable voluntary effort. I t is generally found th a t there is a considerable time lag betw een the dem and fo r effort and the achievem ent o f a co-contraction. A ccording to Stockm eyer, co-contractions are “re ­ ciprocal con tractions a lternating so rapid ly that the shift o f facilitating influences is no t visible and therefore flexors and extensors in term s of observable function are contracting together” . (2) If this definition is accepted, it is doub tfu l w hether a true co-contraction can ever be obtained with rhythm ic stabilization. T he key words in the above definition are ‘a lternating so rapidly’ and K n o tt does n o t a lte rna te her isom etric contractions very rapidly. A lso, the degree of contraction required by the patien t precludes a n a tu ra l stabilization. V oluntary con­ tro l is u n natu ra l in the m aintenance or achievem ent of p ostu ra l tone. Jo in t stability, especially proxim al stability, is essen­ tial fo r skilled m ovem ent and the therapist needs to facilitate this before progressing to distal skills. A m ethod which is fa r less dem anding of both therapist and patient, has been devised to obtain a co-contraction in the extended position (in which co-contraction is functional). I t can also be used to facilitate any muscle group depending on the position of the joint and the po in t o f application of the facilitation. T he jo in t is placed in the desired position and quick, a lternate, sm all-range ro ta tions are applied to any part of the lim b distal to the muscles which are to contract. T he p a tien t is requested to hold the p a r t still i.e. to prevent any ro tation from taking place. It m ay be found necessary to perform the m anoeuver slowly and in a larger range than used to facilitate , in order to ex­ p lain to the p a tien t w hat is required of him. Once the pa tien t understands, it will be found th a t a co-contraction can be elicited w ithout the tim e lag and the intense vo luntary effort so com m only experienced with rhythm ic stabilizations. It has been ound th a t the finer and the m ore rap id ro tations, the greater the facilitation. I t is th ough t th a t co-contraction is initiated by m eans of stim ulation o f secondary afferents of single joint ex­ tensor m uscles. (3, 4) T he optim um position for this is the extended position of the jo in t i.e. the norm al weightbearing position. In Fig. 1 the elbow was held in an extended position. R o tation of the shoulder was applied using the hand as the p o in t of application . T he up p er reading is the e.m.g. recording of the triceps m uscle, the lower is that o f the biceps. T he pap er speed was 25 mm/sec. T he calibration was 1 cm/m volt. In this sim ultaneous recording it can be seen th a t the am plitude and frequency of the action po ten tial spikes are alm ost equal — a true co­ con traction . A sim ilar technique was applied with the elbow held a t 30° (Fig. 2) and 90° (Fig. 3) flexion respectively. T he jo in t angle was m easured and kep t constan t by use o f a L eighton Flexom eter. T he upper reading is the triceps and the low er one, the biceps. (

T h e tech n iq u e of rh y th m ic stabilization as described by K n o tt " em ploys isom etric con tractio n of antagonistic and agonistic p a tte rn s, w hich results in co-contraction of antagonists if the isom etric contraction is not broken by the physical th e ra p ist" . ( 1) In ord er to o b tain the desired co-co n tractio n the th era p ist m ust be extrem ely skilled and the p a tie n t m u st e x ert considerable voluntary effort. It is generally fo u n d th a t there is a considerable tim e lag betw een the dem and fo r effort and the achievem ent o f a co -contraction.
A ccording to Stockm eyer, co-contractions are "r e ciprocal c o n tra ctio n s a lte rn a tin g so rap id ly th a t the shift o f facilitating influences is n o t visible and therefore flexors and extensors in term s of observable function are con tractin g to g eth e r" .
(2) If this definition is accepted, it is d o u b tfu l w heth er a tru e co-contraction can ever be obtain ed w ith rhythm ic stabilization. T h e key words in the above definition are 'a ltern atin g so rap id ly ' and K n o tt does n o t a lte rn a te h e r isom etric contractions very rapidly. A lso, the degree of co n traction required by the p a tie n t precludes a n a tu ra l stabilization. V oluntary c o n tro l is u n n a tu ra l in the m ain ten an ce o r achievem ent of p o stu ra l tone.
Jo in t stability, especially proxim al stability, is essen tial fo r skilled m ovem ent and the th erap ist needs to facilitate this be fo re progressing to distal skills. A m ethod w hich is fa r less dem anding of both therapist and p atient, has been devised to o b tain a co-contraction in the extended p o sitio n (in w hich co-contraction is fun ctio n al). It can also be used to facilitate any m uscle group depending on the p o sitio n of the joint and the p o in t o f a p p lic atio n of the facilitation.
T h e jo in t is placed in the desired position and quick, a lte rn a te, sm all-rang e ro ta tio n s are applied to any p art of the lim b distal to th e m uscles w hich are to contract. T h e p a tie n t is requested to hold the p a rt still i.e. to p revent a n y ro tatio n fro m taking place. It m ay be fo u n d necessary to p e rfo rm the m an o e u v er slowly and in a larg er range th an used to facilitate, in order to ex p lain to the p a tie n t w h at is req u ired of him. Once the p a tie n t understands, it will be fo u n d th a t a co-contraction can be elicited w ith o u t the tim e lag and the intense v o lu n ta ry effort so com m only experienced with rhythm ic stabilizations. It has been ound th a t the finer and the m o re ra p id ro tatio n s, the greater the facilitation.
It is th o u g h t th a t c o-contraction is initiated by m eans of stim u latio n o f secondary afferents of single joint ex ten so r m uscles. (3, 4) T h e o ptim um position for this is the extended p o sitio n of the jo in t i.e. the no rm al weightbearin g position.
In Fig. 1 the elbow was held in an extended position. R o ta tio n of the sh o u ld e r was applied using the hand as the p o in t of ap p licatio n . T h e u p p e r reading is the e.m .g. re co rd in g of the triceps m uscle, the low er is th a t o f th e biceps.
T h e p a p e r speed was 25 m m /sec. T h e calibration was 1 cm /m volt. In this sim ultaneous reco rd in g it can be seen th a t the am p litu d e and freq u e n c y of the action p o ten tial spikes are alm o st eq u al -a true co co n tra ctio n .
A sim ilar technique was a pplied w ith the elbow held a t 30° (Fig. 2) a n d 90° (Fig. 3) flexion respectively. T h e jo in t angle was m easured and k e p t c o n sta n t by use o f a L eig h to n F lexom eter. T h e u p p e r reading is the triceps and the low er one, the biceps. It can be seen th a t w ith an increase in flexion there js far greater activ ity in the biceps, while activity in the triceps is m inim al. T hus this technique can be used to facilitate any m uscle g roup depending on the position 0f the joints and the p o in t of a p p lic atio n of the rotations.
The uses to w hich this tech n iq u e can be p u t are legion, so long as th e joints a re carefully positioned t0 obtain the o p tim al response. Since the contraction o b ta in e d is isom etric, there is no dan g er o f m oving joints w hich m ust be kept im m oblie. T h e one c o n tra indication to this technique is the p a tie n t with a h e art c o m p la in t.
Isom etric contractio n s, p a rtic u la r o f the u p p e r lim bs, a re know n to cause an increase in h e art rate and blo o d pressure. (2) A few exam ples of the uses of quick ro ta tio n s now follow:-(a) F o r facilitatio n of head co n tro l in fo rearm rest pro n e lying, ro ta tio n o f the shoulders can be given T his causes a c o-contraction of the neck m usclesas added facilitatio n to th a t o f the startin g position. (b) Jn o rd e r to fa cilitate action o f the ro ta to r cuff and the sc a p u la r ro tato rs, quick ro tatio n s can be applied in the fo rea rm re st position, to the shoulders (w eak facilitatio n ) or to the fo rea rm s (used as levers to cause ro ta tio n a t the shoulders) o r to th e hands which are gripping cones, fo r even g re ater facilition. If w eight-bearing is n o t allow ed, the arm s can be placed in the bend position and quick ro tatio n s applied. O nce the ro ta to r cuff m uscles a re active, it is possible in the latter position, to superim pose an iso tan ic deltoid c o n tra ctio n w ith a re su lta n t elim ination of a reversed scap u lo -h u m eral rhythm . (c) In lying, quick ro ta tio n s applied to the hip jo in t using the dorsiflexed fo o t as the p o in t o f ap p lic a tion, fa cilitate ham strin g a n d quadriceps activity (particularly vastus m edialis activity).  13. Ibid, p. 67. 14. M elzack, R., W all, P. D . (1965), P ain M echanism s: A N ew T h eo ry , Science, 150, 3699, 791. 15. tbid. 16-L ecture N o tes (1972), " Spinal M a n ip u la tio n C ourse" , S outh A u stra lia n B ranch of th e A u stra lia n P hysio th erap y A ssociation. 17. Personal N otes. to r hallucis. If the toe is held in the dorsiflexed positio n , the q uadriceps is facilitated. T h is is p a r tic u larly useful for patients im m obilized in P.O .P. (e) T ru n k stabilization is obtain ed b y quick ro ta tio n of the pelvis and late r the shoulders in e ith e r sitting or standing. Pelvis ro tatio n can also be applied in the bridging po sitio n w hich causes a very strong tru n k co-contraction. It can th u s be seen th a t this technique offers endless possibilities. O ne m ust b e a r in m ind th a t the position of the jo in t alters the degree o f fa cilitatio n in the desired m uscle. T h e p o in t o f app licatio n o f the ro tatio n s also alters the facilitatio n , the m ore distal the ap p licatio n the g re ater the facilitatio n . T h e technique is sim ple, b u t shaking of the p a rt m u st be avoided. Q uick a lte r n ate rotation of the p a rt is req u ired , n o t flexion a n d extension o r ab-and ad d u ctio n . T h e m ovem ent a pplied should be so fine as to be alm o st im perceptible to the p atien t. W ith this technique it is possible to elicit a co-co n tractio n of any p a rt as w ell as to fa cilitate any w eak o r inhibited m uscle group. I t has also been successfully applied in the early re h ab ilita tio n of p e ri p h e ral nerve lesions and with care, can be used in spastic conditions w here stability is desired.