MSK Anatomy

• Divisions of vertebrae

  • 7 Cervical vertebrae (C1-C7)
  • 12 Thoracic vertebrae (T1-T12)
  • 5 Lumbar vertebrae (L1-L5)
  • 5 (usually all fused) Sacral vertebrae (S1-S5)
  • 4 (some fused) Coccygeal vertebrae (Co1-Co4)
• Curvatures

  • Kyphosis – curve outwards (posteriorly) – Primary
  • Lordosis – curve inward (anteriorly) – Secondary
• Healthy curvatures

  • Cervical lordosis
  • Thoracic kyphosis
  • Lumbar lordosis
  • Sacral kyphosis
• Functions of vertebral column

  • Support
  • Movement
  • Protection (of nervous system)
• Cervical vertebrae

  • Movements: Neck flexion and extension, Rotation, Lateral flexion
  • Muscle and ligament attachments
  • Passage and protection of vertebral artery and vein (C1-C6 only)
  • Atlas and Axis movements: Atlanto-occipital joint – nodding i.e. "yes", Atlantoaxial joint – shaking of head i.e. "no"
• Thoracic vertebrae

  • Attachment site for ribs
  • Muscle and ligament attachment
  • Movements: Rotation, Limited flexion and extension
  • Vertebral bodies get larger as you move down the thoracic spine
• Sacrum

  • Support – weight-bearing
  • Posterior aspect of the pelvis
  • Muscle and ligament attachment
  • Pelvic bone attachment site
  • Sexual dimorphism: Male – Heart-shaped pelvic inlet, Female – Oval-shaped pelvic inlet
• Pectoral Girdle

  Clavicle & Scapula
• Proximal Humerus


  Two necks: surgical and anatomical
• Coccyx

  • Weight-bearing and balance assistance in a seated position
  • Muscle and ligament attachments
  • Positional support for anus – pelvic floor attachments
  • Common fracture site
• Intervertebral Joint

  • Hyaline cartilage lines the inferior and superior aspects of the vertebral body, with a intervertebral disc between each vertebra
  • Intervertebral disc is composed of two parts: Anulus fibrosus and Nucleus pulposus
• Trapezius

  • Location: Back
  • Attachment Points: Spine & Skull to Scapula, Acromion & Clavicle
  • Function: Elevates, rotates, retracts and depresses scapula
• Zygapophysial Joint

  • Joints between vertebral arches via articular processes
  • Specialised for each region and movements: Cervical – Slopes inferiorly from anterior to posterior, Thoracic – Near vertical gradient, Lumbar – Curved and interlock
• Deltoid

  • Location: Shoulder
  • Attachment Points: Scapula, Acromion & Clavicle to Deltoid tuberosity of humerus
  • Function: Abduction of the arm
• Uncovertebral joint

  Minor joint – exists only in cervical vertebrae (usually C3-7) due to the 'lipped' vertebral body (uncinate process)
• Rotator Cuff

  • Overview
  • Muscles: Supraspinatus, Infraspinatus, Teres minor, Subscapularis
  • Location: Shoulder
  • Attachment points: Scapula to head of humerus
  • Function: Stability
• Typical Vertebral Joints?

  • Typical vertebrae has 6 joints: 2 Intervertebral joints, 2 Superior Zygapophysial joints, 2 Inferior Zygapophysial joints
  • Movement between vertebrae is limited, but the summation of these small movements amounts to larger and more noticeable movements
• Pectoralis Major

  • Location: Chest
  • Attachment Points: Clavicle & Sternum (and costal elements) to Humerus
  • Function: Flexion, adduction, medial rotation of humerus + other movements
• Erector Spinae

  Iliocostalis, Longissimus, Spinalis
• Latissimus dorsi

  • Location: Back
  • Attachment Points: Spinous processes (some via thoracolumbar fascia) & iliac crest to humerus
  • Function: Adduction, medial rotation and extension of the arm
• Spinal Cord

  • 31 pairs of spinal nerves: 8 Cervical, 12 Thoracic, 5 Lumbar, 5 Sacral, 1 Coccygeal
  • Spinal cord usually ends between L1-L2, does not extend the whole vertebral column
• Biceps brachii

  • Location: Anterior arm
  • Attachment Points: Scapula to Radial tuberosity
  • Function: Flexion and supination of forearm
• Coracobrachialis

  • Location: Anterior arm
  • Attachment Points: Scapula to humerus
  • Function: Flexion of arm
• Brachialis

  • Location: Anterior arm
  • Attachment Points: Humerus to Ulna tuberosity
  • Function: Flexion of forearm
• Triceps brachii

  • Location: Posterior arm
  • Attachment Points: Scapula & humerus to olecranon of ulna
  • Function: Extension of forearm and extension and adduction of arm (long head only)
• Pelvic Bone

  • Ischium, Ilium, & Pubis
  • Pelvis is composed of two pelvic/hip bones, sacrum & coccyx.
  • Hip/pelvic bone is composed of ilium, ischium, & pubic bones.
  • Fuses during childhood, 3 bones meet in acetabulum.
• Cubital Fossa

  Overview: Transition area between arm and forearm. Lots of structures pass through the region. Anatomy is very important clinically here
• Forearm Compartments

  • Overview: Two compartments - Anterior (Wrist movement, Flexor muscles, Pronation muscles), Posterior (Wrist movement, Extensor muscles, Supination muscles). Separated by the interosseus membrane and a lateral intermuscular septum
• Hand Joints

  • Structure: Wrist joint, Carpal joints, Carpometacarpal joints, Metacarpophalangeal joints, Interphalangeal joints
• Gluteal Region Muscles

  • Gluteus maximus
  • Tensor fasciae latae
  • Gluteus medius
  • Gluteus minimus
  • Piriformis
  • Obturator internus
  • Gemellus superior
  • Gemellus inferior
  • Quadratus femoris
• Gluteus maximus

  • Location: Gluteal region
  • Function: Extensor of flexed femur, Laterally rotates and abducts the thigh, Lateral stabiliser of hip and knee joint through attachment to iliotibial tract
• Tensor fasciae latae

  • Location: Gluteal region
  • Function: Stabilises the knee in extension, Stabilises (with gluteus maximus) the hip joint – holds head of femur in acetabulum
• Gluteus medius and minimus

  • Location: Gluteal region
  • Function: Abducts the femur at the hip joint, Medially rotates thigh, Holds pelvis secure over stance leg and prevents pelvic drop on the opposite swing side during walking
• Other gluteal muscles

  Function: Laterally rotate the extended femur and abduct the flexed femur at the hip joint
• Femoral Triangle

  Overview: Nerve (Femoral nerve), Artery (Femoral artery), Vein (Femoral vein), Lymphatics, Empty space, Lymphatics
• Thigh Muscle Compartments

  • Anterior (Extensor compartment - Act on the knee - extension)
  • Medial (Adductor compartment - Mainly act on hip joint)
  • Posterior (Flexor compartment - Act on the knee - flexion, Also some act on the hip - extension)
• Psoas major & Iliacus

  • Location: Pelvis/Thigh
  • Function: Flexes the thigh at the hip joint, Contributes to lateral rotation
• Quadriceps femoris

  • Location: Anterior thigh
  • Function: Extends the leg at the knee joint, Rectus femoris assists flexion of the thigh at the hip joint, Vastus muscles stabilise patella in knee joint movement
• Sartorius

  • Location: Anterior thigh
  • Function: Flexes the thigh at the hip, and the leg at the knee
• Medial Compartment Muscles

  • Adductor longus, Adductor brevis, Adductor magnus
  • Pectineus
  • Obturator externus
  • Gracilis