Introduction
Loss of conduction or impaired conduction to a muscle, and/or conditions involving the muscle itself can lead to loss of strength in that muscle and, ultimately to, atrophy.
A defect in the extrapyramidal system usually leads to an increase in muscle tone.
In addition, many random movements will occur.
An examination of the patient’s motor function should aim to answer the following questions:
1. Is there loss of strength, and if so, to what extent?
2. Is the cause of this loss of strength the result of:
- a condition involving the muscle itself or the neuromuscular junction?
- a condition involving the peripheral nerve?
- a condition involving the corticospinal tract [Figure 37]?
3. Is there any change in muscle tone?
4. Is the patient making involuntary movements? During the ‘gait and posture examination’, you will already have formed an impression of the normal movement pattern, the muscle contours and any involuntary movements that may be present. The patient’s motor function should be further investigated by means of an examination of muscle tone and muscle strength.
Figure 37