Sit To Stand

Question 1

What are the joints involved

Answer 1

Hip
Knee
Ankle

Question 2

What are the movements at the joints

Answer 2

Leaning forward =
Hip - flexion to bring hip to torso
Knee - slight flexion - knee moves over feet
Ankle - (dorsiflexion) - help shift weight forward

Upward phase
Hip - extension - to lift torso upward
Knee - extension
(1)Ankle - dorsiflexion - pull toes up to allow stability and weight transfer
(2) ankle plantarflexion

Question 3

What are the axes and planes involved in the movements

Answer 3

Sagittal plane and frontal axis

Question 4

What muscles bring about each movement at each joint?

Answer 4

Leaning forward phase
Hip flexion - hip flexors - illiapsoas and rect fem
Knee flexion - hamstrings quadriceps
Ankle plantarflexion - gastrocnemius and soleus
Tib ant in dorsiflexion

Upward phase
Hip extension - glute max
Knee extension - quads
(1)Ankle dorsiflexion - tibialis anterior and soleus as antagonist
(2) ankle plantarflexion - Gastroc and soleus, tib ant contracts eccentrically

Question 5

What range is each muscle working in

Answer 5

Hip flexors = mid to inner
Hamstrings = middle
Glute max = middle
Quads = mid to outer
Gastroc = inner
Tib ant = mid to inner

Question 6

What type of contraction is occurring at the hip in leaning forward phase and standing up phase

Answer 6

Leaning forward:
Hip extensors = eccentrically contract (glute max) as they lengthen
Quads = eccentric contraction
Rect fem - concentrically contract
Hamstrings - isometric eccentric

Standing up:
Hip extensors = concentrically contact (glute max) as they shorten
Hip flexors = isometrically contract - stay same length
Knee extensors (quads) = concentrically contract
Tib ant = concentrically contract

Question 7

What is a concentric contraction

Answer 7

Muscle shortens in length while generating a force against resistance
Muscle fibres pull togther, the sarcomere shortens as the myosin forms cross bridges with the active filaments and a power stroke occurs pulls the actin filaments to the H line
Positive mechanical work - the muscle is generating force and moving a lever

Question 8

What is an eccentric contraction

Answer 8

Muscle lengthens under tension, myosin heads form cross bridges to actin filaments and the actin is pulled away from the centre of the sarcomere
The active and myosin are sliding apart while maintaining some interaction - creating muscle tension

Question 9

Example of an origin-insertion reverse in sit to stand movement

Answer 9

Tibilalis anterior dorsiflexion - origin is moving to insertion

Question 10

Example of eccentric loading in sit to stand movement

Answer 10

The glutes eccentrically lengthen during lean forward phase

Question 11

Any type of active or passive insufficiency in sit to stand

Answer 11

Sit to stand has no insufficieny as we are always in mid range at this movement, it is also a closed chain movement

Question 12

3rd class lever in the sit to stand

Answer 12

Glute max in hip extension in upward phase
Effort is in middle
Fulcrum is hip joint
Load is body weight

Question 13

2nd class lever in sit to stand

Answer 13

??