ESS 303 – Biomechanics

Trunk: Thorax, Spinal Column & Pelvis

7 Cervical

12 Thoracic

5 LumbarSacrum: 5 FusedSacral Vertebrae)

Coccyx: 3-5Coccygeal Vertebrae

IntervertebralDisks

IntervertebralFormina

Bony Landmarks of the Vertebrae

Vertebral Bodies

Intervertebral Disks

Shock absorption Amphiarthrodial joints between vertebrae Disk injuries – bending forward → nucleus

pulposus is displaced backwards Disk degeneration

Stress loading → reduction in disk thickness → loosening of longitudinal ligaments → increased movement

Decreased thickness → narrowing of vertebral foramen → pain, inflammation, poor nutrition

Both of above cause back pain

Vertebral Column

FunctionsSupport body weightProtect the spinal cordProvide mobility

Abnormal curvaturesKyphosis: thoracic & sacralLordosis: cervical, pelvic & lumbarScoliosis: lateral deviation(s)

Kyphosis

Kyphosis

Lordosis

Lordosis

Lordosis

(First 7)

(Next 3 – 8, 9, & 10)

(Last 2 – 11 & 12)

Biomechanics of Breathing

Visualize a bucket handle

External intercostals and sternocleidomastoids – elevate ribs – inspiration

Internal intercostals – depress ribs - expiration

Movements & Major Muscles

Flexion: Rectus abdominis, internal & external obliques

Extension: Erector spinaeLateral flexion: Internal & external

obliques & erector spinaeRotation: Internal (same side) &

external (opposite side) obliques & erector spinae (opposite side)