15: 1st Ray, 1st MPJ - Feilmeier

Question 1

hallux bears weight for ______ of stance

Answer 1

60%

met 1 bears weight 80% of stance

Question 2

first ray takes ____ of body weight in gait

Answer 2

35%

Question 3

loss of hallux purchase reduces …

Answer 3

push off power and increases lateral loading

Question 4

first ray is a ______ segment

Answer 4

stability

Question 5

what is the first ray?

Answer 5

1st metatarsal and medial cuneiform

Question 6

motion of first ray (Hicks)

Answer 6

dorsiflex -invert - adduct

plantarflex - evert - abduct

Question 7

total ROM of first ray **

Answer 7

10 mm (1 cm) 
5 mm dorsal
5 mm plantar

Question 8

“hypermobile 1st ray”

Answer 8

• greater than 8 mm dorsal mobility
• total ROM over 15-20
• is it related to bunion?

Question 9

*** orientation of first ray axis Hicks

Answer 9

proximal-medial-dorsal to distal-lateral-plantar direction

Question 10

______ rotation has been shown to be consistent in HAV

Answer 10

valgus metatarsal rotation

Question 11

*** positioning for measuring stability first ray

Answer 11

STJ neutral

midtarsal joint lock

Question 12

1st Ray function in gait

Answer 12

• plantarflexion durign midstance and propulsion necessary for proper 1st MPJ function (allows dorsiflexion in toe off)
• requirements: supinated subtalar joint, stable midtarsal joint

Question 13

in a mechanically stable foot, ______ stabilizes lesser tarsus and 1st met against ground allowing plantarflexion of 1st ray

Answer 13

• peroneus longus

- active plantarflexion by intrinsics

Question 14

function of 1st MTPJ in gait

Answer 14

provide stability for propulsion

Question 15

normal 1st MTPJ movement requires

Answer 15

• stability and plantarflexion of 1st ray
• normal sesamoid function (act as pulleys for muscles required for hallux stabilization during propulsion)
• normal function of 1st MTPJ muscle stabilizers

Question 16

what type of joint is the 1st MTPJ?***

Answer 16

ginglymoarthrodial

• hinge/ginglymoid 1st 20 degrees
• gliding/sliding/arthroidal motion

Question 17

when is there sliding motion at 1st MTPJ

Answer 17

• with plantarflexion of 1st ray with heel lift, STJ supination and normal seasmoid function

Question 18

failure of 1st MTPJ to plantarflex causes impingement of met head on proximal phalanx of hallux –>

Answer 18

• causes joint erosion and inflamamtory reaction in cartialge and bone ends
• trauma stimulates the bone to grow, effect of osteogenic development is firstly to restrict and later to cause total seizure of joint
• loss of movement at first MTPJ may cause pain, which can lead to disruption of biomechaical function of foot and limb due to compensation and can compromise gait

Question 19

*** average ROM of 1st MTPJ compared to bisection of 1st met

Answer 19

dorsiflexion 60-65

plantarflexion 5-10

Question 20

average ROM of 1st MTPJ compared to plantar surface of foot

Answer 20

dorsiflexion 20

plantarflexion 45

Question 21

what do you need at 1st MTPJ for gait?

Answer 21

• appropriate functional position, for stable push-off

- not ROM

Question 22

what is hubscher maneuver?

Answer 22

• dorsiflexion of hallux in relaxed stance position
• engages windlass mechanism
• determines functional hallux limitus (WB prob, no prob NWB)

Question 23

less ray plantarflexion is required for ..

Answer 23

MPJ dorsiflexion during propulsion

Question 24

should you fuse 2,3,4, and 5 mets?

Answer 24

no - 5th should be separate b/c has independent ROM

Question 25

info about the lesser MTPJs

Answer 25

• toe stabilization due extrinsic and instrinsic musculature

- dorsiflexion is by extensor digitorum longus through extensor sling

Question 26

what is the kelikian push-up test?

Answer 26

• push up on met heads and watch what happens to digits at MPJ, PIPJ
• determines degree of fixed/structural deformity

Question 27

what is the drawer/lachman test?

Answer 27

• checks for the stability of the joint
• stabilize the met head and attempt to dorsally translocate the proximal phalanx
• greater than 2 mm or 50% joint displacement is positive