gait and orthotics

Question 1

prerequisites of normal gait

Answer 1

• stability in stance
• clearance in swing
• pre-positioning of foot in swing
• adequate step-length
• conservation of energy

Question 2

kinematics

Answer 2

study of positions, angles, velocities, accelerations of body segments and joints during motion

Question 3

kinetics

Answer 3

study of forces, moments, and powers acting within and on the body

Question 4

moment =

Answer 4

force x distance

Question 5

power =

Answer 5

moment x joint angular velocity

Question 6

initial contact also known as

Answer 6

heel strike

Question 7

initial contact GRF’s

Answer 7

passes through the heel
- posterior to ankle (ankle neutral)
- anterior to knee (knee extended
- anterior to hip (hip flexed)

Question 8

initial contact muscles activated

Answer 8

• hip extensors (glute max, hamstrings)
• pre-tibial muscles

Question 9

loading response is also known as

Answer 9

shock absorption

Question 10

loading response GRF’s

Answer 10

• posterior to ankle (ankle PF’s from neutral)
• posterior to knee (knee flexes)
• through the hip (hip less flexed; extending)

Question 11

loading response muscles activated

Answer 11

• pre-tibial muscles (eccentric; control ankle pf)
• quad femoris (eccentric; control knee flexion)
• glut med and adductor magnus (concentric; contralateral pelvis stabilization)

Question 12

mid-stance is also known as what

Answer 12

extrinsic stability of the knee

Question 13

mid-stance GRF’s

Answer 13

• anterior to both knee and ankle (restrained df; knee extension)
• posterior to hip (hip stabilization in coronal plane)

Question 14

mid-stance muscles activated

Answer 14

• soleus and gastroc (eccentric; control tibial forward advancement/df
• glut med (concentric; abductors stabilized pelvis in level posture)

Question 15

extrinsic stability of the knee during mid-stance is provided by what

Answer 15

eccentric activation of the soleus/achilles tendon
- maintains GRF anterior to the knee > knee extension

Question 16

during what part of gait does the plantarflexion/knee extension couple happen

Answer 16

mid-stance

Question 17

terminal stance also known as what

Answer 17

acceleration

Question 18

terminal stance GRF’s

Answer 18

anterior to knee and posterior to hips > knee and hip extension

Question 19

terminal stance muscles activated

Answer 19

• gastroc and soleus (eccentric; stabilize tibia at ankle) (concentric; push off)
• tensor fascia lata and iliopsoas (eccentric; restrains hip hyperextension)

Question 20

pre-swing consists of

Answer 20

• weight transfer to contralateral limb
• unlock stance limb for swing

Question 21

pre-swing GRF’s

Answer 21

• passes through metatarsals
• posterior to knee

Question 22

pre-swing muscles activated

Answer 22

• rectus femoris (control excessive knee flexion and hip flexion)
• iliopsoas
• adductor longus (decelerate passive abduction caused by weight transfer to other foot)

Question 23

swing phase muscles activated

Answer 23

• triceps surae (pre-swing)
• hip flexors (pre and initial swing)
• contralateral hip extensors pull body forward

Question 24

initial swing consists of

Answer 24

momentum from rapid hip flexion advances femur while tibial inertia from toe-off leads to knee flexion

Question 25

initial swing muscles activated

Answer 25

- iliopsoas and rectus femoris - sartorius and gracilis (hip and knee flexion) - pretibial muscles (ankle df)

Question 26

mid-swing consists of

Answer 26

transition from knee flexion to knee extension

Question 27

mid-swing muscles activated

Answer 27

pretibial muscles (ankle df)

Question 28

terminal swing consists of

Answer 28

deceleration of swing limb

Question 29

terminal swing muscles activated

Answer 29

- medial and lateral hamstrings (1st half) (restrain hip flexion and prevent excessive knee ext) - quad femoris (2nd half) (complete knee ext) - pretibial muscles (foot and toe clearance)

Question 30

what contracts and lengthens to control forward progression of the tibia over the foot during midstance

Answer 30

gastroc-soleus contracts and achilles tendon lengthens - directs GRF anterior to knee - provides extensor moment at knee

Question 31

first rocker

Answer 31

ankle pf slightly with small df moment produced by eccentric contraction of the ankle df to prevent foot slap

Question 32

second rocker

Answer 32

ankle df with gradually increasing pf moment as body center of mass moves forward and center of pressure of the GRF moves distally produced by the eccentric contraction of the pf

Question 33

third rocker

Answer 33

ankle begins to pf with increasing pf moment produced by concentric contraction of ankle pf

Question 34

drop foot

Answer 34

persistent ankle pf during swing phase, too much pf or too little df

Question 35

drop foot treatment

Answer 35

external device like e-stim or FES

Question 36

equinus

Answer 36

one foot is toe walking

Question 37

knee hyperextension atypical gait

Answer 37

result of overly effective PF/knee extension coupling - persistent flexion moment at knee

Question 38

knee flexion atypical gait

Answer 38

- persistent knee flexion through stance and swing - underperforming or ineffective PF/knee extension couple

Question 39

knee flexion atypical gait also known as

Answer 39

crouched gait - usually only in kids

Question 40

unintended effects of orthotic usage

Answer 40

- limitations in segmental mobility during ambulation - limitations in higher-level gross motor skills - long-term changes in soft tissue characteristics (creep) - skin irritation/breakdown - psychosocial impact

Question 41

limitations in segmental mobility during ambulation caused by orthoses examples

Answer 41

- medial/lateral heel whip - compensatory power generation at hip

Question 42

limitations in higher-level gross motor skills caused by orthoses examples

Answer 42

- getting up from floor - stair negotiation