motor system examination physiology ppt.pptx

motor examination

1. Py 10.11EXAMINATION OF THE MOTOR SYSTEM

2. The examination of the motor system includes: Bulk of muscles Tone of muscles Strength (or power) of muscles Reflexes Coordination of movements Gait Presence or absence of involuntary movements

3. This is estimated by inspection an palpation. Measure the circumference of the arm, forearm, thigh and leg at an identical level on both sides. The level should be decided in relation to some fixed, subcutaneous bony landmark. Judgment regarding the presence of muscular wasting or otherwise depends most often on a comparison of the two sides. Wasted or Atrophic muscles are smaller, softer and more flabby (loose) than normal when they contract. Muscle wasting associated with fibrosis is called contracture . The muscle feels hard, inelastic and shortened. Therefore, it is not possible to stretch them passively to a normal degree. Bulk of muscles

4. The bulk of muscle decreases in: (a) injury or disease of a muscle/joint, such as inflamed muscles or during prolonged hypertonia in a group of muscles; (b) neurological disorders; (c) cachexia of any cause The bulk of muscle increases in : athletic training, continued excessive workload in certain occupations like carpenters, labourers, etc. myotonic disorders

5. Definition: Certain amount of tension present in the resting muscle due to low frequency and asynchronous discharge of gama - motor neuron which produces the resistance of a muscle to stretch . This is referred to as the ‘tone’ of a muscle.. How to assess muscle tone: Clinically, muscle tone is assessed by moving the muscles passively at their various joints and feel for resistance is normal, low or high. Tone of muscles

6. Hypotonia : Decrease in resting muscle tone. Such muscle offer little or no resistance to stretching. Causes are: During sleep Lower motor neuron lesion, i.e. destruction of local reflex arc anywhere in its pathway. For example, Destruction of efferent (motor) nerve to a muscle by injury or poliomyelitis; Destruction of afferent (sensory) nerve as seen in syphilis ( tabes dorsalis ).

7. Hypertonia: Increase in resting muscle tone. Such muscles offer high resistance to stretch. It is commonly seen in upper motor neuron lesion. In brain diseases which cause increase in muscle tone if hypertonia is confined to only one group of muscles, it is called spasticity. However, when hypertonia involves both groups of muscles, extensor as well as flexor, equally, it is referred to as rigidity. For example, the lesions of internal capsule produce spasticity, whereas basal ganglia lesions lead to rigidity

8. How to Test: Each movement made during this assessment is tested by comparison with the examiner’s own to be normal in a person of comparable build to the patient. Testing for the strength of individual muscle : Muscles of upper limb (i) Abductor pollicis brevis: abduct the thumb in a plan at right angles to the palmar , against the examiner’ s own thumb (ii) Interossei and lumbericals : Flex the metacarpophalangeal joint and to extend the distal inter-phalangeal joints. (iii) Flexors of the finger: squeeze your fingers (iv) Flexors the wrist : Bring the fingers towards the front of forearm. (v) Extensors of the wrist : Forcibly to flex the wrist against his effort to maintain his posture. (vi) Brachioradialis : Place the forearm in mid-prone position . Then flex it against résistance Strength (or power) of muscles

9. (vii) Biceps: Place the forearm in full supination and then flex it against résistance . The muscle stand out clearly. (viii) Triceps : Place the forearm fully flexed against the chest and then ask him to straighten it out against resistance. ( ix) Supraspinatus and Deltoid: Ask the subject to lift his arm straight out at right angles to his side against resistance. The first 30 degree of his movement carried out by the supraspinatus .and the remaining 60 degree is product by deltoid.

10. (i) Abdomen muscles: Babinski’s rising up sign. The Weakness of these muscles is shown by the inability to sit up in bed from the supine position without the aid of his arms. (ii) Diaphragm : In a healthy individual, inspiration is associated with bulging and expiration with the fall of abdominal wall. Opposite occurs in the paralysis of the diaphragm. (iii) Trapezius: (a) upper part ask the subject to shrug his shoulders against the examiner’s resistance. (b) lower part ask him to approximate the shoulder blades. Muscle of the trunk

11. (i) Dorsiflexion and planter flexion of the feet and toes. (ii) Extensors of the knee. Ask the subject to flex his knee and then pressing with your hand on his shin. Ask him to try to straighten it out again. (iii) Flexors of the knee. Raise the leg up from the bed. Support the thigh with your left hand and hold the ankle with your right hand. Then ask the subject to bend his knee. Muscles of the lower limb

12. MRC Scale for grading muscle power Grade Complete paralysis Grade 1 A flicker of contraction only Grade 2 Power detectable only when gravity is excluded by postural adjustment Grade 3 Limb can be held against gravity but not resistance Grade 4 Limb can be held against gravity and some resistance Grade 5 Normal power

13. Definition: This means the smooth recruitment, interaction and cooperation of separate muscles or group of muscles in order to perform a definite motor act. The coordination of muscle movement depends on: Sense of position of a limb or joint. Cerebellar functions The state of tone of muscles Ataxia : A disturbance in the coordination of muscle movement. It is of two type . (i) Sensory ataxia (ii) Cerebellar ataxia Coordination of movements

14. TEST FOR CORDINATION OF MOVEMENTS In the upper limb 1.Finger-nose test – Ask the subject to first touch his nose with his own index finger and then the examiner’s index finger. Then he is asked to perform the same action with his eyes closed. If he performs these movements without making errors, coordination is normal. Irregularity indicates the impairment of position sense in the limb. Adiadochokinesia : The person is unable to carry out rapidly alternate and opposite movements. For eg : Rapid supination and pronation of the forearm. Dysdiadochokinesia : When the movements are slow, incomplete with irregular rhythm, and often become impossible after a few attempts.

15. In the lower limb: If the person is able to walk, Ask him to walk along a straight line. If in coordination is present, he will soon deviate to one side or the other. If he cannot walk, perform Heel-Knee Test with the eyes open. Ask him to place the heel of his leg on the opposite knee and then to slide the heel along the shin of the tibia towards the ankle. Romberg’s Sign : The person is asked to stand with his feet close together, and if he can do this, then ask him to close his eyes. If Romberg’s sign is present, as soon as his eyes are closed. he begins to sway about or may fall.

16. Gait means manner of walking. Requirements for examination of gait: 1.The legs should be fully exposed. 2.The feet should be bare. 3. Examine the bone and joints. Spastic (Hemiplegic) Gait : The person has difficulty in bending his knees and drags his feet as if they are glued to the floor. It is seen in pyramidal tract lesions . Gait

17. Stamping gait: Stamping means to strike the ground heavily. The person raises his feet very suddenly, often abnormally, high, and the jerks them forward, bringing them to the ground again with a stamp, and often heel first. It is seen in sensory ataxia.

18. Drunken (Reeling) Gait: The person walks awkwardly with the feet well apart. They have such difficulty in maintaining balance, that it appears drunken, called drunken gait. It is seen in cerebellar lesion.

19. Festinant gait: The person bends forward, and walks quickly with short steps as if trying to catch up centre of gravity or preventing himself from falling down. It is seen in Parkinson’s disease.

20. Waddling Gait: Waddling means to walk with short steps like the gait of duck. The person plants his feet widely apart and the body sways from side to side as each step is taken. It is seen in proximal muscular weakness (myopathies, muscular dystrophies).

21. INVOLUNTARY MOVEMENTS EPILEPSY Involuntary movements limited to one side of the body Movement is usually complex, repetitive and stereotyped which last for short duration It may be increased by arousal TICS: These are normal movements which become repeated unnecessarily to the point that they become an embarrassment or a source of, or reaction to, psychiatric problem. It commonly involves the face and shoulders and usually develops early in life, also called habit spasm. Eg : Head nodding, blinking, cheek/lips/nail/ biting, laryngeal tic, etc.

22. TREMORS Regular or irregular distal movements having an oscillatory character are referred as tremors. Classification : Fine and Rapid tremors : seen in anxiety, thyrotoxicosis Coarse and Irregular tremors : eg . a) Senile tremors: seen at rest and during movements b) Hysterical tremors: increased when attempt to control it Resting tremors: consist of regular, rhythmic, alternate movements of muscles@ 6-8/sec. seen as pin rolling movements. Common site is fingers, hand, lips. As these tremors are present at rest and disappears during activity , so called as Resting tremors Intentional tremors: these tremors are coarse @4-6/sec and are seen when the person tries to do some voluntary movement. Seen in cerebellar dysfunction

23. Athetosis : It is primarily due to the lesion of the lenticular nucleus and is characterized by continuous, slow-twisting movements (one phase of movement getting merged with the next). Chorea : It is mainly due to there involvement of caudate nucleus and is characterized by: Rapid, irregular involuntary movements of short duration and is associated with decreased muscle tone and muscular weakness.

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