Muscoskeletal Skeleton: Complex Movements

• What is Quadrupedal Standing?


  It is standing on 4 limbs.

  It is the base of our support and our limbs are active at many joints and requires energy.
• What are the limbs that contribute to quadrupedal standing?


  shoulder, knee, elbow, wrist, hip, ankle
• Where is the energy required in quadrupedal standing?


  It comes from the muscle that are actively engaging in maintaining the posture.
• What is Bipedal Standing? 


  A small area of contact with the ground - plantar surface on the feet.

  It is the combination of skeletal structure muscle arrangement and efficient breathing, which is energy efficiency.
• What are the muscle roles?

  • Agonists - concentrically
  • Antagonists - eccentrically
  • Stabilisers - isometrically
• What is the line of gravity?


  The direction of gravitational force acting on an object or body.
• How do we maintain a stable, upright stance by line of gravity?


  It aligns the body so that the line of gravity passes through the base of support.

  • Energy efficient
  • requires anatomical solutions
• Line of Gravity body description:

  1. Posterior to hip
  2. Anterior to knee
  3. Anterior to ankle
• What is bipedal standing - hip?

  line of gravity is posterior to joint that pushes joint to extension, which is locked.

  Energy spent.
• What is bipedal standing - knee?

  Line of gravity is anterior to the joint (locked) and pushes into extension and the ligaments are tight. Energy spent.
• What is bipedal standing - ankle?

  line of gravity is anterior to joint (unlocked) and pushes into dorsiflexion and the plantar-flexors need to stabilise.

  Energy consumed.
• What is the gait cycle?

  A walking cycle that is complex and dynamic. It encompasses the period from initial contact of one foot with the ground to the contact of the same foot.
• What are the two phases of gait cycle?

  Swing and Stance.
• What are the stances of Gait Cycle?

  1. Early stance + heel strike
  2. Mid Stance
  3. Late stance
  4. Early swing
  5. Mid swing
  6. Late swing
• Describe Early Stance

  hip - in flexion, but moving to extension

  knee - in extension and locked in for stability (quadriceps, femoris, hamstrings)

  ankle - in dorsiflexion,

  • agonists = triceps surae
  • antagonist = tibialis anterior need to control rate of foot drop to ground.
• Describe Mid Stance

  hip - continue moving into extension

  • agonists = gluteus maximus and hamstrings

  knee - moving from extensio into slight flexion

  • agonists = hamstrings and gastrocnemius

  ankle - continuing to move into plantarflexion

  • agonists = triceps surae
• Describe Late Stance

  hip - in extension

  • agonists = gluteus maximus and hamstrings

  knee - in extension due to posture of body

  ankle - in full plantar flexion

  • agonists = triceps surae
• Early swing

  hip - in extension

  • agonists = illiopsas and rectus femoris
  • antagonists = gluteus maximum and hamstrings

  knee - in flexion to lift from ground

  • agonists = hamstrings and gastrocnemus

  ankle - in dorsiflexion to allow clearance of toes during swing

  • agonist = tibialis anterior
• Mid swing

  hip - in flexion

  • agonists = illiopsoas and rectus femoris
  • antagonists = gluteus maximus and hamstring

  knee - in flexion to lift foot from ground

  • agonists = hamstrings and gastrocnemus

  ankle - in dorsiflexion to allow clearance of toes during swing

  • agonists = tibialis anterior
• Late Swing

  hip - in flexion

  • agonist = illiopsoas and rectus femoris

  knee - moving into extension to prepare heel strike

  • agonists = quadriceps femoris

  ankle - in dorsiflexion for most stable joint position for heel strike

  • agonist = tibialis anterior
  • stabiliser = triceps surae