The Back

Anatomy of the back

The spinal  column or backbone is comprised of a column of small bones or  vertebrae (singular  vertebra) which are  connected by  cartilaginous joints.

There  are seven  cervical  vertebrae in the neck,  twelve  thoracic vertebra in the chest  (to which the ribs are attached) five lumbar  vertebrae in the lower   back,   and  five  sacral  vertebrae. The  sacral   vertebrae are  fused to  form  the  sacrum  which comprises part  of the  pelvic  girdle  and  the coccyx   is  the  final  part   of  the  spine.   The  spinous   processes  of  the vertebrae are  small  bony  projections that  protrude posteriorly and  can easily  be palpated along  the midline of the back.

The  vertebrae are  numbered  sequentially from  skull  to  coccyx  using a letter  to denote the region  of the spine  and  the numbering starts again at 1 for each new  region. So cervical vertebrae are C1-C7.  C7 is next to T1 and T12 is next to L1.

PP Back B-1

PP Back B-1

PP Back B-1

Each pair  of adjacent vertebrae is connected by facet  joints  (also called apophyseal joints),  which both  stabilise  the vertebral column and  allow movement in it (Facet just means a small  flat surface).  Each vertebra has two  sets of facet  joints.  There  is one  joint  on  each side  (right and  left). Facet  joints  are  hinge-like  and   link  the  vertebrae  together. They  are located at the back  of the spine  (posterior).

The vertebrae (except  between C1 and  C2 in the neck)  are separated by intervertebral discs  of a  jelly-like  substance held  in  a  fibrous  sheath. Each vertebra and disc can move only a limited  amount but the net effect of several  vertebrae moving  is to  allow  considerable flexibility  of the spine   without reducing  stability.  The  amount of  movement in  lateral flexion,  flexion  extension and  rotation varies  at  different  levels  of the spine.

The vertebrae are  stabilised by two  major  ligaments. The anterior longitudinal ligament is a broad, strong  band  of fibres extending along the   front  and   sides   of  the   vertebrae  and   the   posterior  longitudinal ligament extends along  the posterior surface.

The spine  provides a bony  protective sheath for the spinal cord   which is a collection of nerve  cells  and  a bundle of nerves  that  connect all parts of the  body  with  the  brain.  The spinal  cord  ends  at the  second lumbar vertebra but large nerves  descend vertically from the spinal  cord  through the lumbar and sacral  regions  in a structure called the cauda equina. The major  nerves  of the  body  leave  the  spinal  cord  at different  levels  of the spine  to  take  information to  and  from  the  brain.  There  are  31  pairs  of spinal  nerves  that  leave  the  spinal  cord  passing  out  from  the  vertebral canal through the spaces (foramina) between the arches of the vertebrae. There  are also lumbar, sacral  and  coccygeal spinal  nerves  that pass from the  spinal  cord  via the  cauda equina and  leave  the  vertebral column in the lumbar, sacral  and  coccygeal regions.

These  nerves  can  become damaged, squashed or trapped giving  rise to symptoms down the arms or in the hands. These may be anaesthesia (loss of  feeling)   parasthesia  (pins  and   needles)  pain   or  weakness  of  the relevant muscle. Such  nerve  damage is commonly seen  in  prolapsed intervertebral discs  (‘slipped  disc’) when  the  distribution of the  sensory or  motor   effects  enables  the  exact   site  of  the  damaged  disc   to  be predicted.

The pain  or loss of sensation will be felt in the distribution of that nerve (the parts of the body  supplied by that nerve)  or may be referred  to other body  regions. The weakness will be of muscles supplied by that nerve.

Two  important nerves  in  this  context are  the  sciatic  nerve,  the  major nerve of the leg and the femoral  nerve,  which supplies the thigh muscles.

PP Back 3a

PP Back B-1
Back pain

Back  pain   is  a  very  common  and   troublesome  complaint,  affecting around 70%  of the  population. Back  pain  can  be  caused by  systemic disease, or sepsis (infection). There are also structural conditions such  as facet  joint arthritis,  or prolapsed intervertebral discs.

Causes of back pain

Mechanical/degenerative Disc degeneration

Apophyseal  (facet) joint OA

Back strain

Non-specific causes

Inflammatory Spondyloarthropathies
Metabolic Osteoporosis with fracture
Infection Infection is an uncommon but important cause. This should always be thought of by the doctor as early diagnosis and treatment is necessary
Tumours Tumours are an uncommon but important cause. This should always be thought of by the doctor as early diagnosis and treatment is necessary
Disc problems Herniated disc


Sciatica  is due  to compression of the  sciatic  nerve  that  supplies the  leg and  is accompanied by  pain  running down the  back  of the  leg  from buttock to ankle.  Prolonged sciatica can  lead  to muscle weakness.

Back strain  due  to lifting or twisting  is a common cause of back  pain  in younger people and  is usually  self-limiting.

Degeneration of the intervertebral discs and OA of the apophyseal (facet) joints   is  extremely  common  with   ageing   and   it  is  often   without symptoms. In the majority of cases  of back  pain  in older  people there  are no  obvious causes apart  from  the  degeneration that  occurs with  age. Sometimes, obesity  or excessive use of the spine  by manual workers  may be contributory factors.

There is a group  of inflammatory rheumatological conditions that involve the spine,  sacroiliac joints, and peripheral joints, called the spondyloarthropathies. These  include ankylosing   spondylitis, psoriatic arthritis,  reactive arthritis,  enteropathic arthritis  and  undifferentiated spondyloarthropathy.

Unlike  mechanical back  pain,  which gets  worse  with  physical activity and is usually  more pronounced at the end of the day, inflammatory back pain  is usually  worse  after periods of inactivity  and in the early morning. Severely affected  patients may wake  from sleep  in the early hours  and be unable to lie comfortably.

Giving a history of spinal problems

Invite the doctor to carry out a consultation by first asking you about your history  related to the  experience you  have  of your  condition. This will then  be followed by the physical examination.

The doctor should first ask you  ‘What  is the  problem?’ and  you  should give a short response describing your symptoms and  their effect on your quality  of life.

Develop a script  based on your  own  experience. You may  still have  the symptoms or  you  may  be  describing an  episode you  have  had  as  if it were  still present.

Describe as fully as you can your own  symptoms, including where in the back or elsewhere you feel/felt pain or discomfort. The pain often spreads into the buttock and  leg.

Describe whether you  have/had any  tingling  in  your  legs  and/or feet. Say if you have  any stiffness, swelling  or other  symptoms. Mention how the  problem is having/had an  impact on  your  daily  life,  your  work  or your sleep.

Remember to describe how  your  condition affects/affected your  quality of life.  Consider self care  (e.g.  ability  to  wash,  dress,  toilet  and  feed), domestic care  (e.g.  ability  to  cook,   clean, launder, shop),  work  (e.g. ability  to stand,  sit, type), leisure  (e.g. ability  to play sports,  walk,  go out for  meals).  Explain  about the  way  it  limits/limited your  activities and restricts/restricted your participation in normal life.

Do  not  tell  him  everything  spontaneously  –  just  the  important part. He  will  then  need to  ask  further  questions to  fully  characterise your problem. Develop a  set  of answers with  your  trainer  to  the  following points.  Prompt  them  if they omit important questions.

Pain is usually  present and  questions should establish:

  • How the pain  started  and  developed.
  • The nature of the pain.
  • The exact distribution of the pain.
  • Whether the pain has increased or decreased over time.
  • Whether it affects sleep.
  • Whether anything exacerbates or relieves the pain. Stiffness may be a symptom and  questions should establish:
  • If you are stiff at all?
  • When it is worse?
  • What improves it?

Swelling  may be a symptom and  questions should establish:

  • If you have noticed any swelling  and  where.
  • If it is always present.
  • If it is painful or tender.
  • If it is increasing.

They  need to  ask  about the  pattern of all  the  symptoms – where they started  and  if they have  spread anywhere.

You may  prompt the doctor (if you have  not already told  them)  to make sure that they include the following information:

  • Your age, occupation and  hobbies.
  • Whether you have injured or strained your back.
  • Your general health  and   whether  you  have   been feeling   ill,  lost weight   or  have   had   a  fever   –  this  is  to  make   sure   that   some uncommon but serious  causes of back  pain  are not missed.
  • Your past medical history.
  • Whether you have   any  symptoms such   as  tingling,   numbness  or weakness in your legs.
  • Back problems typically cause difficulty  with  a lot of activities that involve  bending, lifting, carrying, prolonged standing or sitting.
  • Whether you have  had  previous treatment and  if so whether it was successful.

The  effect  of  any  problem depends on  your  personal circumstances. The doctor needs to know  about what  you  need to do  in the  home, at work,  your leisure  interests  and  your expectations.

You may  have  symptoms affecting  other  parts  of your  musculoskeletal system.  You may prompt the doctor to ensure he has asked  whether you have  any  other  problems affecting  your  muscles, joints,  neck  or  back.

You may go into further  details  about how  your problem affects your life and  the  treatment you  have  received at  the  end  of the  session  when discussing the findings.

Example of a Script

You should develop something like this, based on your own  story. First you need to ask me:

What is your problem?

“I have  had back  pain  intermitently for five years and this episode started a month ago following gardening. It is at the bottom of my back  and also my left buttock. It stops me standing for any period of time and  I cannot lift anything heavy.”

You should then  respond to questions, guiding  and prompting the doctor through the information as listed  above.

Spine Examination Script

Describe  the   examination  to  the   doctor  using   the   anatomical and directional  terms   you   have   learnt. You  can   use   your   knowledge   of anatomy  best  when   the  doctor  is  feeling   the  joint  and   periarticular structures.

“I  would now   like  to  invite  you  to  find  out  a  little  bit  more  about my problems, by role play, using me as your patient and examining me.”



Inspect  the patient’s  upright  posture from the front, side  and  back.  Note the  alignment of the  spine  and  assess  whether there  are  any  postural defects  such as scoliosis,  kyphosis  or lordosis. Place  fingers lightly on the shoulders and  iliac crest  to assess  alignment of the shoulders and  hips.

Look for muscle wasting, limb shortening, swelling  or deformity.

PP Back 3a

What do you see?



Facing  the  patient’s   back,  gently  but  firmly  tap  the  spinous processes with your index  and middle fingers or use the index  and/or middle finger to  feel  for tenderness over  a  spinous process which would indicate a local  lesion  at that site.

Diffuse lumbar tenderness is usually  not significant.

Feel the paraspinal muscles approximately 2.5  cm (1”) on either  side  of the  spinous processes for signs  of tenderness. Using  a circular motion keep  the fingers in contact with the skin so as not to miss any findings.


What do you feel?



Flexion and  hyperflexion You can  assess  lumbar flexion  by  asking  the patient to stand  in the erect  posture with their back towards you and then to  bend  forwards  with  knees  fully extended as  if trying  to  touch their toes. Note  the range  of movement by how  far the finger tips are from the floor, the presence of spasm  of muscles, pain  on movement, deviation to one   side   or  another  (sciatic   scoliosis)   or  the   induction  of  sciatica (indicative of nerve  root compression). Look from the side as well to see if the spine  is making  a smooth arch.

If the  patient does  not  have  any  limitation in the  previous test – ask the patient while  in this position, to place their  hands flat on  the  floor. The ability  to do so indicates hypermobility syndrome.

When they  are  trying  to  touch the  ground, put  the  second and  third fingers of one  hand  on the lower  lumbar spinous processes and  see how the fingers close  up when  the patient stands  upright. This is a measure of movement of the lumbar spine.

PP Back 3a

Lumbar extension

Stand  behind the patient with his or her back  to you and  ask him or her to bend  backwards trying  to arch  his or her  back  as much as possible. The normal angle  is 30°.  Restricted range  denotes spinal  problems.

Pain on extension may indicate facet  joint  syndrome, but is also seen  in cases  of herniated discs.

PP Back 3a

Lateral flexion

Ask the patient to bend  to the right and then  to the left as if trying to edge his/her  fingers as far as the knee.  Usually  the finger tips should reach as far as  the  middle of the  thigh.  Reduction of lateral  flexion  is typically seen   in  ankylosing spondylitis  but  is  characteristically relatively   well preserved in mechanical low back  pain  and  disc prolapse.

PP Back 3a

PP Back 3a

Sitting  Rotation

Ask  the   patient  to  sit  comfortably  facing   you   on   the   edge   of  the examining table  with  legs  hanging free.  Ask them  to  turn  their  upper trunk  as  far  as  possible to  the  right.  Gently   guide  their  shoulders to ensure that the maximum range  has been reached. Repeat  this procedure to the left

PP Back 3a

PP Back 3a

What have you found?


Listen for any signs of crepitus.

Special tests

The  lumbar spine  is a region  where nerves  can  easily  be  compressed. The examination of the lumbar spine  should therefore include neurological examination of  the  lower  limbs  and  the  performance  of tests that detect the presence of tension affecting  the nerve  roots in either the femoral  or sciatic  nerves,  which are nerves  supplying the legs.

Lightly touch the palmar and  dorsal  surfaces  of the feet and  toes and  ask if sensation is normal. Test strength  by asking  the patient to dorsiflex  the foot  and  the  big  toe  against   resistance and  then  plantar flex  the  foot against  resistance. (Dorsiflexion or just flexion  involves  moving  the  top of  the  foot  towards the  shin  and  plantar  flexion  or  extension, is  the opposite movement otherwise known as pointing your toes).

Test for sciatica  (sciatic  nerve root compression) With  the patient lying supine and  the  leg  straight,  gently  raise  the  patient’s  leg  from  the  bed observing for distress and asking about pain  in the back  or down the leg. Normally you  should be  able  to raise  the  leg to 60°  – 90°.  An angle  of less  than   60°   because  of  pain   is  a  positive   result.   Tight  hamstring muscles, which may limit leg movement and cause pain  behind the knee must  be distinguished from true sciatica. Pain  down the leg distal  to the knee   suggests   sciatic   nerve   root   compression.  When  the   ankle   is dorsiflexed any  increase in pain  confirms  the  presence of sciatic  nerve root compression. Repeat  the test with the other  leg.

PP Back 3a

Test for cruralgia (femoral  nerve  root compression) Cruralgia is not  as common as sciatica. This test involves  stretching the  femoral  nerve  and looking  for pain  in the  anterior thigh  of the  same  leg. With  the  patient lying  prone and  relaxed take  hold  of the  patient’s  ankle  and  passively flex the  knee  as far as it will go without causing discomfort or distress. Pain  in  the  anterior thigh  indicates  compression of  the  roots  of  the femoral  nerve  on that side.  Repeat  the test with the other  leg.

PP Back 3a

“We  have  now  come to the  end  of this mock  consultation. You should have    learned   quite    a    bit    about   my    condition   from    taking my  history  and  examining my  joints,  however, I would be  happy to provide you  with  a bit more  detail  about the  progress of my condition and  how  it affects my life, if you would find this useful.”

[Please give a brief description of your  condition:

  • When and how  it started.
  • Physical and psychological affects  on you.
  • Treatments offered.
  • How your  condition progressed.
  • How this affected your life: Home, education, work,  leisure,  ability to travel, relationships etc.]

“Does anyone have  any further  questions?”

“Thank   you  again   for  attending this  session. I hope   you  have   found it useful.”
















Lateral flexion

Ask the patient to bend  to the right and then  to the left as if trying to edge his/her  fingers as far as the knee.  Usually  the finger tips should reach as far as  the  middle of the  thigh.  Reduction of lateral  flexion  is typically seen   in  ankylosing spondylitis  but  is  characteristically relatively   well preserved in mechanical low back  pain  and  disc prolapse.