About The Spine

The Shape of the Spine

The nor­mal adult spine is bal­anced over the pelvis, requir­ing min­i­mal work­load on the mus­cles to main­tain an upright pos­ture. When viewed from the front or back, the nor­mal spine is in a straight line, with each ver­te­bra sit­ting direct­ly on top of the oth­er. Cur­va­ture to one side or the oth­er indi­cates a con­di­tion called sco­l­io­sis. When viewed from the side, the nor­mal spine has three grad­ual curves. These curves help the spine to sup­port the load of the head and upper body, and main­tain bal­ance in the upright posi­tion. Exces­sive cur­va­ture, how­ev­er, may result in spinal imbal­ance.

The Spinal Column

The spinal col­umn is one of the most vital parts of the human body, sup­port­ing our trunks and mak­ing all of our move­ments pos­si­ble. Its anato­my is extreme­ly well designed, and serves many func­tions, includ­ing move­ment, bal­ance, shock absorp­tion, pos­ture and spinal cord pro­tec­tion.

The spinal col­umn is made up of sev­er­al parts, includ­ing the ver­te­brae that sup­port the major­i­ty of the body’s weight, discs which func­tion as shock absorbers, facet joints that con­nect the ver­te­brae, the neur­al fora­men where the nerve roots exit the spine, and spinal cord and nerves. There are also a vari­ety of spinal mus­cles that con­nect to the spinal col­umn.

Humans are born with 33 sep­a­rate ver­te­brae. By adult­hood, we typ­i­cal­ly have 24 due to the fusion of the ver­te­brae into the tri­an­gu­lar bone at the base of the spinal col­umn. They are com­prised of the fol­low­ing:

  • Cer­vi­cal spine: the top 7 ver­te­brae that form the neck are labeled C1-C7. These ver­te­brae are respon­si­ble for the nor­mal func­tion and mobil­i­ty of the neck. They also pro­tect the spinal cord, nerves and arter­ies that extend from the brain to the rest of the body.
  • Tho­racic spine: the 12 ver­te­brae that make up the upper back are labeled T1-T12.
  • Lum­bar spine: the 5 ver­te­brae that make up the low­er back are labeled L1-L5. The lum­bar spine bears the most weight rel­a­tive to oth­er regions of the spine, which makes it a com­mon source of back pain.
  • The sacrum and coc­cyx (tail­bone): these 9 ver­te­brae are fused togeth­er to form a sol­id, bony unit.

All of the ele­ments of the spinal col­umn and ver­te­brae serve the pur­pose of pro­tect­ing the spinal cord, which pro­vides com­mu­ni­ca­tion to the brain, mobil­i­ty and sen­sa­tion in the body through the com­plex inter­ac­tion of bones, lig­a­ments and mus­cle struc­tures of the back and the nerves that sur­round it. Prob­lems with this com­plex sys­tem can cause pain and even dis­abil­i­ty.