The Tonie and Respiratory Action of the Trapezius. 
By T. Wineate Topp, M.B., F.R.CS., 
Lecturer in Anatomy, University of Manchester. 
With 2 Figures. 
In a former paper contributed to this journal I have dealt with 
the influence of the recti muscles of the abdomen on the position of 
the manubrium sterni and adjacent portions of the 4st ribs. (6) I 
have there shown that by its determination of the slope of the thoracic 
operculum, the tonic contraction of these muscles exerts a powerful 
force in adjusting the position of the inner end of the clavicle. 
In the paper mentioned, I have dealt inadequately with the in- 
fluence of the trapezius muscle on the position of the outer end of 
that bone. I propose now to discuss this important function of the 
trapezius in greater detail. 
It is well known that if the upper portion of one trapezius be 
paralysed, the affected shoulder drops below the level of the normal 
shoulder and cannot be raised voluntarily by the patient. The effect 
of this falling of the shoulder is twofold. First the weight of the 
whole arm rests upon the chest, and secondly there may occur 
mechanical (stretching) lesions in the 5th and 6th nerves passing to 
the brachial plexus. 
A case exhibiting some of these features came under the notice 
of the writer some two years ago. A.S., a man of 27, was suffering 
from tubercular adenitis on the right side of his neck. At the 
operation (Jan. 17th 1910) it was found necessary to resect one inch 
of the spinal accessory nerve, which was readily identified, being an 
example of that variety which passes across the posterior triangle in 
a single fair-sized trunk. After his discharge the patient returned 
complaining of inability to raise the shoulder and of pains in the 
sensory area supplied by the circumflex nerve. Unfortunately the 
patient died of phthisis florida some months afterward and thus I 
was unable to make a prolonged study of his case. There was no 
“cervical” rib present, nor any cause for the circumflex disturbance 
other than the mechanical one due to the dropping of the shoulder. 
Sensory symptoms similar to these are liable to come on more or 

