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Flashcards in Sit to Stand Deck (18):
1

What are the 3 phases of STS?

1. prep phase
2. rising phase
3. stability phase

2

Phasing is identified by _____ and divided equally such that each phase is 1/3 of STS cycle.

velocity of GRF

3

What happens to COM during prep phase?

moves forward and down

4

Prep phase, AKA _______, goal?

"flexion momentum phase"
goal: est trunk position

5

Describe the start and end kinematics of the preparation phase:

start: hip/knee 90*, ankle 15*
end: hip 110*, knee 90*, ankle 20*

6

What are the prime movers of preparation phase?

concentric hip flexors = initiation of movement
eccentric back/hip extensors, eccentric ankle PF, isometric knee flexors/extensors

7

Rising phase, AKA ______, goal?

"momentum transfer phase"
goal: produce extension force

8

What happens to COM during rising phase?

rises vertically

9

Describe the start and end kinematics of the rising phase:

start: hip 110*, knee 90*, ankle 20*
end: hip 10*, knee 5*, ankle 5*

10

What are the prime movers of rising phase?

concentric: hip/knee extensors, ankle PF
eccentric: hip flexors decelerate COM at end of phase

11

What happens to COM during stabilization phase?

COM moves A/P and M/L to attain balance control

12

Stabilization continues until theres is less than ____ N fluctuation of the vGRF.

<5 N
(marks the end of the stabilization phase)

13

What are the two biomechanical strategies for STS and how are they differentiated?

momentum transfer: horizontal velocity COM > 0.4 m/s
stabilization transfer: horizontal velocity COM < 0.4 m/s

14

Which biomechanical strategy sacrifices efficiency?

stabilization transfer
(more stable)

15

Which biomechanical strategy sacrifices stability?

momentum transfer
(more efficient, requires speed and balance)

16

COM is over the BOS in _________ transfer strategy.

stabilization transfer

17

COM is separated largely from BOS in _________ transfer strategy.

momentum transfer

18

What are two stabilization phase strategies?

1. hip: hip flexors and extensors work concentrically and eccentrically
2. ankle: ankle PF and DF work concentrically and eccentrically