Lecture 14 Flashcards
Why does quadrupedal walking use a lot of energy?
- base of support is large
- legs flexed at several joints
- lots of energy used to maintain standing
and due to muscle contraction
Why does bipedal walking use less energy?
- relatively small area of contact with ground
- plantar surface of feet
- energy efficient
What is the action of gravity?
Agonist
OR
Antagonist
What happens when sitting down?
what happends when we stand up?
Gravity is agonist when we sit down, but rate determined by antagonist = gluteus maximums and hamstrings (eccentrically)
Gluteus maximus is agonist (concentric).
Gravity is antagonist which determines rate of coming up
- it resists movement
Where is the line of gravity on the hip joint?
- posterior to joint
- joint ‘pushed’ into extension
- extension = ligaments are tight = locked
> energy efficient since only the ligaments are working and not the muscles
the ligaments are the capsular ligaments which are important for resisting tension (three different ligaments attaching the hip to the femur)
Where is the line of gravity on the knee?
- anterior to joint (to keep it straight)
- joint ‘pushed’ into extension
- extension = ligaments are tight = locked
> with the help of the capsular ligaments and the collateral and cruciate ligaments to help lock the knee)
energy efficient
What is the line of gravity on the ankle?
- anterior to joint
- ‘falls’ into dorsiflexion
- not locked
- plantarflexors stabilise
- energy consumed
> to oppose falling forward, muscles need to do work
uses the triceps surae to contract and do planteflex( stabiliser)
Bipedal walking is….
- is learnt
- gait is characteristic
- basic pattern is gait cycle
- STANCE and SWING phase
- ‘heel-strike’ and ‘toe-off’ (propelling your self off the ground)
HIP
EARLY STANCE Flexed Iliopsoas Agonist Concentric
MID STANCE Extension into AP Gluteus Maximus Agonist Concentric
LATE STANCE Extension Gluteus Maximus Agonist Concentric
EARLY SWING Flexion into AP Iliopsoas Agonist Concentric
MID SWING Flexed Iliopsoas Agonist Concentric
LATE SWING Flexed Iliopsoas Agonist Concentric
KNEE
EARLY STANCE Extended Quadriceps Agonist Concentric
MID STANCE Extended Quad femoris Stabiliser Isometric
LATE STANCE
Flexed
Passive due to momentum through stance.
EARLY SWING
Flexed
Passive – no need for hamstring action.
MID SWING
Extending
Passive – pendulum motion.
LATE SWING Extended Quadriceps Agonist Concentric
ANKLE
EARLY STANCE Dorsiflexed Tibialis anterior Agonist Concentric
MID STANCE
Neutral (AP)
Gravity - agonist
Tibialis anterior – antagonist, eccentrically
LATE STANCE Plantarflexed Triceps surae Agonist Concentric
EARLY SWING Dorsiflexion to AP Tibialis anterior Agonist Concentric
MID SWING Dorsiflexed Tibialis anterior Stabiliser Isometric
LATE SWING Dorsiflexed Tibialis anterior Agonist Concentric
