Complex Movements

Question 1

Bipedal starting - contact with ground and energy expendature

Answer 1

• relatively small area of contact with ground
• plantar surface of feet
• energy efficient

Question 2

Recap of muscle roles…

Answer 2

Agonists act concentrically
Antagonists act essentrically
Stabilisers act isometrically

Question 3

Gravity’s assistant with movement of the body

Answer 3

• can act as an agonist and antagonist

Question 4

Line of gravity in bipeds

Answer 4

• line of gravity assists processes
• Posterior to hip
• Anterior to knee
• Anterior to ankle

Question 5

Bipedal standing - line of gravity with HIP

Answer 5

• LOG is posterior to joint
• joint ‘pushed’ into extension
• in extension the ligaments are pulled tight holding bones together - LOCKED JOINT
• this means we don’t need activation of muscles spending a lot of energy

Question 6

capsular ligaments of the hip joint actions during specific actions

Answer 6

Hip in flexion: lax anteriorly, taught posteriorly
Hip in extension: taught anteriorly, lax posteriorly

Posterior is very tight because gravity is behind

Question 7

Bipedal standing - KNEE

Answer 7

• anterior to joint
• joint ‘pushed’ into extension
• ligaments (collateral ligaments) pull tight JOINT LOCKED

(in flexion the lossen allowing rotation)

Question 8

Bipedal standing - ankle

Answer 8

• anterior to joint
• gravity makes you want to ‘fall’ into dorsiflexion
• requires active muscles to stop this, platartfelxion to push back and hold joint isomentrically
• plantar flexors stabilises
• not locked
• energy consumes

Question 9

Bipedal standing - summary

Answer 9

• bipedal stance unique to humans
• feet form base of support, but insufficient size to provide only balance solution
• bones, joints and muscles have special anatomical features to assist balance solution
• standing achieved with very little muscular effort - mostly at ankle joint