Volume 1

A manual of diseases of the nervous system / by W.R. Gowers.

Date:
1886-1888
Catalogue details

Licence: Public Domain Mark

Credit: A manual of diseases of the nervous system / by W.R. Gowers. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    45/488 (page 25)
    / moved forwards by the serratus, is rotated on its veiiical axis by the action of the anterior part of the deltoid on the humerus, and of the middle part on the scapula. Thus the posterior edge recedes from the thorax, leaving a groove into which the hand can sometimes be placed (Pig. 8). The scapula is, at the same time, rotated ; lower angle inwards and up- wards. Elevation of the ann above the level of the shoulder is much weakened, but can be imperfectly ef- | fected by the middle part of the trapezius. Loss of the | serratus weakens othermove- | ments, but does not abolish i any. Inspiratory expansion of the thorax, when the arms are raised, is distinctly less on | the paralysed side (Poore). | The Deltoid (circumflex |'' nerve, from the four lowest |? cervical) abducts the hu- |i merus, the anterior and pos- terior fibres also moving the arm forwards and backwards respectively. The arm is raised least by the posterior, and most by the anterior fibres, but even the latter only elevate it to a right angle with the trunk. Hence, if raised by the anterior fibres, and then moved back by the posterior, it is at the same time depressed. Elevation above a right angle is by rotation of the scapula (trapezius and serratus). These muscles also fix the scapula for the deltoid, preventing the rotation (acro- mion down, lower angle in) that the deltoid, acting alone, would cause. In paralysis, abduction of the arm, direct, forwards, and backwards, is almost lost. All the abduction that remains is a trifling movement by the supraspina- tus. An attempt to abduct results in rotation of the scapula and elevation ^^S- 9—P«>'fy7 of ght deltoid; ele- of thfi sbmiUor a\ e vation of shoulder by trapezius on an ot the shoulder (P,g. 9) from an ex- attempt to raise tl.e arm, which is cessive innervation of the associated slightly abducted by the supraspinatus. 1; Fig. 8.—Paralysis of the serratus magnus; eversion and rotation of scapula when the arm is put for- wards.