SPINAL INJURIES 



IV 



Injuries and deformities. Because of the great 

 strain to which the spine is often subjected, minor in- 

 juries and deformities are not uncommon. They are 

 caused mainly by wrenching or tearing some of the 

 ligaments, by bruising the articular surfaces, and by one- 

 sided growth and development due to irregularities in 

 the shapes and numbers of the bones, to faulty postures, 

 or to the habitual carrying of heavy weights upon one 



FIG. 13. Side and back views of correct and faulty positions at school desks. 

 (Tubby.) 



side of the body. Children who carry heavy babies are 

 frequently deformed in this way. 



Head. The spinal column, which serves as the axis 

 of the skeleton, is surmounted by the bones of the head. 

 Here, man's difference from other animals is most pro- 

 nounced, in that the face bones are smaller and the 

 brain cavity, the cranium, is larger. The accompanying 

 illustration shows more accurately than any description 

 the shape and position of the cranial and face bones. 



Appendages of the spine. In addition to the verte- 

 bral column surmounted by the skull, the -bony frame- 

 work of the body also includes the shoulder girdle, the 

 ribs and the pelvic girdle. The shoulder girdle carries 

 the arms and consists of two shoulder blades or scapulae, 

 two collar bones or clavicles, and the breast bone or 



