Hip Biomechanics

Hip Biomechanics

1. Nerves and arteries

   • Obturator nerve
   • Major gluteus nerve
   • Femoral nerve
   • Internal and external circumflex artery

2. Femur neck is useful to support the femur head. It also supports union with diaphysis

3. Joint Surfaces

   • Femoral head
   • Acetabulum

4. Ligaments

   • previous
     • Iliofemoral
     • Pubofemoral
   • POSTERIOR
     • Ischiofemoral
   • Internal
     • Orbed

5. Movements are

   • External Rotation
     • Tiptoe goes out
       • All anterior ligaments tense, at maximum iliopetrocanter and pubofemoral, posterior becomes distended
         • Muscles in this movement are
           • Piriform
           • Internal and external obturato
           • Upper and lower geminates
           • Square crura
     • 0°-50°-60°
   • Internal Rotation
     • Tiptoe goes in
       • Posterior ligament tenses and anterior ligaments become distended
         • Muscles in this movement are
           • Minor gluteusr
     • 0°-30°-40°
   • Aduction
     • Lower member goes closer middle line
       • Iliofemoral tenses, pubofemoral and ischiofemoral becomes distended.
         • Muscles in this movement are
           • Adductors
     • 0°-30°
   • Abduction
     • Lower member goes farther of middle line
       • Pubofemoral and ischiofemoral tense, iliofemoral ligament becomes distended.
         • Muscles in this movement are
           • Medium gluteus
     • 0°-45°
   • Extension
     • Lower member goes behind the body
       • All ligaments tense, the most tensed is the iliopretrocanteric because of vertical fibers.
         • Muscles in this movement are
           • Major gluteus
     • Extended knee: 30°-40° Flexed knee: 10°-20°
   • Flexion
     • Lower member goes near the trunk
       • All ligaments become distended, for this reason is the most unstable position.
         • Muscles in this movement are
           • Iliacum psoas
     • Extended knee: 90° Flexed knee: 120°-140°