ASSISTED EXERCISE
THE PRINCIPLES OF ASSISTANCE
When the force exerted on one of the body levers by muscular action is sufficient for the production or control of movement, an external force may be added to augment it. This external force must be applied in the direction of the muscle action but not necessarily aat the same point, as a mechanical advantage can be gained by increasing the leverage. The magnitude of this assisting force must be sufficient only to augment the muscular action and must not be allowed to act as a substitiue for it, for if it does a passive movement results. As the power of the muscle increases, the assistance given must decrease proportionally.
TECHNIQUE
The general plan is to ensure that the inefficient muscles exert their maximum effort to produce movement under conditions designed to facilitate their action. The assisting force is applied only to augment this maximum effort and not to act as a substitute for it
Starting position – stability for the body as a whole ensures that the patient’s whole attention is concentrated on the pattern of movement and the effort required to perform it
Pattern of movement – this must be well known and understood by the patient. It can be taught by passive movement or in the case of limb movements by active movement of the contralateral limb.
Fixation – adequate fixation of the bone of origin of the prime movers improves their efficiency. Whenever possible this fixation should be achieved by active means in order that the weak muscles may receive reinforcement from of those muscles with which they normally associate for the production of voluntary movement. When there is a tendency for movement to be transferred to neighbouring joints to compensate for the inefficiency of the weak muscles, movement in these joint must be controlled or ‘held back’ by manual pressure or other means of fixation, so that the movement is provided at the required joint.
Support – the part of the body moved is supported throughout to reduce the load on the weakened muscles by counterbalancing the effects of the force of gravity. This support may be provided by the physiotherapist’s hands, suspension slings, polished horizontal surface such as re-education board, the buoyancy of water or ball-bearing skates. Advantage of manual support is that it can be effective in whichever plane is most suitable for the movement and the assistance adjusted to what is required in each successive part of the range.
The antagonistic muscles – every effort must be made to reduce tension in the muscles which are antagonistic to the movement. The starting position for the movement should be chosen to ensure that tension in these muscles is minimal, e.g. a position in which the knee is flexed is suitable for assisted dorsiflexion of the foot.
Traction – preliminary stretching of the weak muscles to elicit the myotatic (stretch) reflex provides a powerful stimulus to contraction. Other means of facilitating the activity of the muscles may also be used.
The assisting force - the force used to augment the action of the muscles is applied in the direction of the movement, preferably by means of the physiotherapist’s hands, which should be placed in such in way that they rest on the surface of the patient’ skin which is in the direction of the movement. In some cases the patient’s own hands may be substituted for those of the physiotherapist, provided the thoroughly understands the procedure.
The range of movement is as full as possible, but as the power of muscles varies in different parts of their range more assistance will be necessary in some parts than in others. In general, most assistance is required to overcome the initial inertia at the beginning of movement and at the end to complete the range. The assistance provided by mechanical means varies in different parts of the range according to definite physical laws and therefore it cannot be adjusted to meet the precise requirements of the muscles, with the result that their maximum effort is rarely elicited and all too frequently the movement becomes passive in character.
The character of the movement - the movement is essentially smooth as this is characteristic of efficient voluntary movement and it is performed in response to a forceful command which demands the patient’s full attention. The speed of movement depends on the muscles involved as each has its own optimum rate of contraction which varies according to its structure and the load. Generally speaking fusiform muscles contract rapidly and multipennate ones take longer. Very weak muscles cannot be expected to produced a sustained contraction and therefore assistance is giver ‘in step’ with the contraction which may only be evident as a flicker in the early stages but as power increases the speed of the movement can be decreased.
Repetition – the number of times the movement is repeated depends on whether it is considered advisable or injurious to fatigue the muscles in question; therefore the condition which has caused the weakness must be known and understood.
The co-operation - of the patient is essential during this type of exercise, the aim being for him to achieve controlled active movement without assistance. Concentrated effort is needed to encourage the muscles to do all they can to help the movement, so praise, well earned, should not be stinted. The ability to see results and to feel what is happening is a great help to the patient so he can be encouraged to palpate his muscles as they contract.
EFFECTS AND USES OF ASSISTED EXERCISE
-The working muscles co-operate in the production of movement which they are incapable of achieving unaided. Provided the maximum effort of which they are capable is demanded from the weak muscles and the assisting force utilized is only complementary, these muscles will gain in strength and hypertrophy.
The type of exercise may be used in the early stages of neuromuscular re-education.
-The memory of the pattern of co-ordinated movement is stimulated by the correct performance of a movement which the patient is unable to achieve without assistance. By frequent repetition of the correct pattern with decreasing assistance, the patient may re-learn to control the movement himself as the conduction of impulses is facilitated in the neuromuscular pathways.
Assisted exercise may therefore be helpful in training co-ordination.
-Confidence in the ability to move is established when the Patient observes the movement and the fact that his muscles co-operate in producing it. The knowledge that the limb is supported throughout and that the movement attempted will be achieved encourages the patient to make a maximum efforts.
When movement must be maintained in spite of pain in joints these exercises are very useful, e.g. in Rheumatoid arthritis.
-The rang of effective joint movement may be increased by assisted exercise; however, as both range and control are often dependent on the efficiency of the muscles working over that joint, a technique which utilize resisted exercise for these muscles for these muscles is usually preferable.THOSE ABOVE ARE COLLECTED FROM SOME BOOKS AND
WEBSITES..
(The
Principles of Exercise therapy - M. Dena Gardiner)
THANK YOU,
SRIKUMARAN
PHYSIOTHERAPY CLINIC & FITNESS CENTER
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