CHAPTER X. 



DISEASES OF MUSCLES, TENDONS, FASCLE, AND 

 BUBS.E. TALIPES. 



MUSCULAR DYSTROPHIES. 



THE distribution of the wasting in the muscular dystrophies 

 does not correspond to that met with in infantile paralysis or in 

 progressive muscular atrophy. In both the latter diseases there 

 is reason to believe that the distribution is determined by the 

 segmental representation of muscles in the spinal cord. Neither 

 does the wasting in the dystrophies correspond to the groups of 

 muscles supplied by individual peripheral nerves. It has been 

 assumed, on slight evidence certainly, that the muscles which are 

 the first to be developed in the foetus are the first to become 

 degenerated when muscular dystrophy supervenes. 



A knowledge of the influence of various muscles in producing 

 the normal contour of the body, and also of their actions, is 

 essential for the investigation and discrimination of the various 

 types of muscular dystrophy. The annexed table shows the 

 muscles which need investigation in the different forms, but it 

 must not be forgotten that intermediate varieties occur, and that 

 sometimes the disease is exceedingly widespread. 



The deltoid abducts the humerus to a right angle, and in so 

 doing tends to rotate the scapula so that the acromion points 

 downwards. This tendency is counteracted by the contraction of 

 the acromial fibres of the trapezius. The anterior fibres of the 

 deltoid carry the arm forwards in a horizontal plane. The fibres 

 forming the posterior third of the muscle are said to adduct the 

 arm to the body. When the deltoid is paralysed the shoulder 

 becomes flattened and the head of the humerus tends to sink 



