FSHP Academy
Human Anatomy — all lessons

Foundations of Anatomy

Anatomical terminology, planes, axes and movement directions

The Skeletal System

Skeletal system: structure and functionsBone structure, remodelling and adaptation to loading

Joints and the Muscular System

Joint types and classificationJoint mechanics: arthrokinematics and stabilityThe muscular system: organisation and major muscle groupsMuscle architecture: pennation, length and cross-sectional areaMuscle fibre types

Regional Functional Anatomy

Spine and postureThe shoulder complexThe hip complexThe knee complexThe ankle and foot complexCore and pelvic stabilityElbow and wrist functional anatomyCervical and thoracic spine functional anatomy

Spine and posture

The structure and curves of the vertebral column, how the spine moves and carries load, and what research actually says about posture and pain.

Intermediate Evidence: Strong evidence 3 min read Reviewed 2026-10-31 Status: draft

Learning objectives

  • Describe the regions, curves and components of the vertebral column
  • Explain how intervertebral discs and facet joints share load and guide movement
  • Summarise the evidence on posture and low back pain
  • Apply a load-tolerance (rather than “perfect posture”) approach in training

Before this lesson

Why this matters

Back pain is the leading cause of years lived with disability worldwide [hartvigsen2018], and posture is the most common explanation offered to clients. Trainers need both an accurate picture of spinal anatomy and an honest picture of the evidence.

Fundamental concepts

Regions and curves of the vertebral column A side view of the spine with the front of the body on the left. Seven cervical vertebrae form a forward-convex curve (lordosis); twelve thoracic vertebrae form a backward-convex curve (kyphosis); five lumbar vertebrae form a forward-convex lordosis; below them the sacrum (five fused vertebrae) and coccyx curve backward. Vertebral bodies become larger from top to bottom as they carry more load. ← Anterior Posterior → Cervical (C1–C7) lordosis — convex anteriorly Thoracic (T1–T12) kyphosis — convex posteriorly Lumbar (L1–L5) lordosis — convex anteriorly Sacrum (5 fused) & coccyx kyphotic curve Vertebral bodies enlarge downward, matching load
Figure 1. Regions and curves of the vertebral column (side view, front of body to the left). — Original diagram, FSHP Academy (schematic, not to scale).
  • Cervical (C1–C7) — lordosis; C1 (atlas) and C2 (axis) are specialised for head nodding and rotation.
  • Thoracic (T1–T12) — kyphosis; articulates with the ribs, which limit motion.
  • Lumbar (L1–L5) — lordosis; largest bodies, carry the most load.
  • Sacrum (5 fused) and coccyx — link the spine to the pelvis.

A typical vertebra has an anterior body (load-bearing), a posterior arch enclosing the spinal canal, and facet (zygapophyseal) joints. Between bodies sit intervertebral discs: a fibrous annulus fibrosus around a gel-like nucleus pulposus [neumann2017].

The science: movement and load sharing

RegionFavoured motionsWhy
Upper cervicalNodding (C0–C1), rotation (C1–C2)Specialised joint shapes
Lower cervicalFlexion/extension, lateral flexion, rotationOblique facets
ThoracicRotation, lateral flexion; limited flexion/extensionRibs, coronal facets
LumbarFlexion/extension; little rotationSagittal facets

Discs carry most compressive load in neutral and flexed positions; facets share more load in extension. Discs have little blood supply and rely on movement and loading cycles for nutrition. Discs, ligaments and muscles all adapt to load over time.

What the evidence says about posture

A systematic review of systematic reviews found no consensus that spinal posture (sitting, standing, lifting posture) causes low back pain [swain2020]. Clinicians have argued that teaching people their posture is “dangerous” can increase fear and protective guarding, which may themselves be linked to persistent pain [slater2019].

That does not mean position is irrelevant: tissue loading changes with position, and an individual may find certain positions provocative. The practical message is variety and capacity, not one “correct” posture.

Practical application

Common mistakes and misconceptions

  • “Never bend your back.” Spinal flexion is normal and trainable; fear of bending is associated with worse outcomes in back pain.
  • “Disc bulges on scans explain pain.” Disc changes are common in people without pain and increase with age.

Case study

Client: Vikram, 41, software engineer with recurring low back pain, convinced his “slouching” is the cause. The trainer screens for red flags (none), reassures, encourages position changes and walking breaks, and builds a progressive programme of hip hinges, carries, side planks and gradually loaded flexion and extension. After eight weeks his pain episodes are fewer and his confidence bending to lift his child has improved. Pain persisting or worsening would prompt referral to a physiotherapist.

Further learning: video lessons

Video links are only marked “verified” after a human has watched them. Unverified entries open a YouTube search for that channel and topic rather than a guessed link.

Introductory needs verification — opens a YouTube search

Anatomy of the vertebral column

Kenhub

You will understand: regions, vertebra structure and discs

Why: Clear labelled anatomy.
Technical needs verification — opens a YouTube search

Posture and back pain — what the evidence says

physiotherapy educators (search; e.g. Peter O'Sullivan lectures)

You will understand: why posture is a weak explanation for most back pain

Why: Research-led perspective from clinical academics.

Knowledge check

Knowledge check · 0/5

1. How many lumbar vertebrae do most people have?

Answer C. Typically 5 lumbar (L1–L5), though transitional variants exist.

2. The thoracic curve is a…

Answer B. Thoracic and sacral curves are kyphotic (convex posteriorly).

3. Which region allows the most axial rotation?

Answer B. Facet orientation in the lumbar spine limits rotation; thoracic and especially C1–C2 allow more.

4. What did a systematic review of systematic reviews conclude about spinal posture and low back pain?

Answer B. Swain et al. (2020) found no consensus supporting a causal role of spine posture.

5. The nucleus pulposus is…

Answer B. It is surrounded by the fibrous annulus fibrosus.

Short-answer & application questions

  1. Explain why “sit up straight” may not be the most helpful advice for someone with back pain at a desk.
  2. Describe how disc and facet loading changes between spinal flexion and extension.
  3. List the red flags that require referral when a client reports back pain.

Key takeaways

  • The spine has 7 cervical, 12 thoracic and 5 lumbar vertebrae, plus the sacrum and coccyx, arranged in lordotic and kyphotic curves.
  • Intervertebral discs and facet joints share load; each region’s facet orientation favours different movements.
  • Systematic reviews have not established that particular postures cause low back pain.
  • Variety of positions and graded loading build capacity; fear of “bad posture” can worsen pain behaviours.

Connected topics

anatomy

Core and pelvic stability

anatomy

Cervical and thoracic spine functional anatomy

corrective exercise

Lumbar spine

prehab rehab

Understanding pain science and tissue healing

assessment

Limits of movement screens and postural assessment

References

  1. Swain CTV, Pan F, Owen PJ, Schmidt H, Belavy DL (2020). No consensus on causality of spine postures or physical exposure and low back pain: a systematic review of systematic reviews. Journal of Biomechanics, 102:109312. doi:10.1016/j.jbiomech.2019.08.006 Systematic review check pending
  2. Slater D, Korakakis V, O'Sullivan P, Nolan D, O'Sullivan K (2019). “Sit up straight”: time to re-evaluate. Journal of Orthopaedic & Sports Physical Therapy, 49(8):562–564. doi:10.2519/jospt.2019.0610 Narrative review check pending
  3. Hartvigsen J, Hancock MJ, Kongsted A, et al. (2018). What low back pain is and why we need to pay attention. The Lancet, 391(10137):2356–2367. doi:10.1016/S0140-6736(18)30480-X Narrative review check pending
  4. Neumann DA (2017). Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation (3rd ed.). Elsevier. Textbook check pending

Educational content only — not medical advice. Consult a qualified clinician for diagnosis or treatment.