propulsive period

1st Ray Plantarflexion

• After the MTJ completely locks, any subtalar inversion will also cause forefoot [...] 

inversion 

1st Ray Plantarflexion

• [...] muscle is primarily responsible for plantarflexing the first ray and keeping it firm against the sesamoids 

Abductor Hallucis

1st Ray Plantarflexion

• [when?]

• 1st ray plantarflexes and everts. Why?
  

  • As the STJ supinates, the first ray must plantarflex farther while the heel is being lifted higher and higher

  • Also so the head of the first metatarsal can stay in contact with the ground relative to the 2nd metatarsal (which is longer) and keep even pressure on the sesamoids

  • Also to allow 65 degree dorsiflexion of the hallux 

• Starts late in midstance in response to rearfoot supination

1st Ray Plantarflexion

• Starts late in midstance in response to rearfoot supination

• 1st ray plantarflexes and everts. Why?
  

  • [...]

  • [...]

  • [...]

• As the STJ supinates, the first ray must plantarflex farther while the heel is being lifted higher and higher

• Also so the head of the first metatarsal can stay in contact with the ground relative to the 2nd metatarsal (which is longer) and keep even pressure on the sesamoids

• Also to allow 65 degree dorsiflexion of the hallux 

Change in the medial and lateral column during propulsion

• Medial column = [...]

• Lateral column = [...] 

• stability

• mobility 

During propulsion, center of gravity is shifted to [...]

the opposite foot 

External rotation at the knee due to:

• [...]

• Tibia rotates farther and faster than the femur

Hip flexion

• During propulsion, hip begins to flex and continues to flex

• Pelvis and thigh?
  

  • [...]

• Thigh is externally rotating farther and faster than the pelvis resulting in net external rotation

Review: hip was extending during both contact and midstance period 

Metatarsal Phalangeal Dorsiflexion

• Metatarsal heads becomes [...] for [...] to exert a plantarflex force on the toes, thus stabilizing them against the ground

pulleys for long digital flexors

Metatarsal Phalangeal Dorsiflexion

• Normal motion
  

  • dorsiflexion of the digits at the MPJ until [...]

  • Simultaneously, interphalangeal joints are forcible extended by the extensor muscles

    • During final moments of propulsion, interphalangeal joints flex slightly

  • When the heel lifts, GRF dorsiflexes the digits into the ground 

the respective metatarsal heads lift from the ground (starting from the 5th)

Metatarsal Phalangeal Dorsiflexion

• Normal motion
  

  • dorsiflexion of the digits at the MPJ until the respective metatarsal heads lift from the ground (starting from the 5th)

  • Simultaneously, interphalangeal joints are forcible [...] by the [...] muscles

    • During final moments of propulsion, interphalangeal joints flex slightly

  • When the heel lifts, GRF dorsiflexes the digits into the ground

extended by the extensor

Metatarsal Phalangeal Dorsiflexion

• Normal motion
  

  • dorsiflexion of the digits at the MPJ until the respective metatarsal heads lift from the ground (starting from the 5th)

  • Simultaneously, interphalangeal joints are forcible extended by the extensor muscles

    • During final moments of propulsion, interphalangeal joints [...]

  • When the heel lifts, GRF dorsiflexes the digits into the ground

flex slightly

Metatarsal Phalangeal Dorsiflexion

• Normal motion
  

  • dorsiflexion of the digits at the MPJ until the respective metatarsal heads lift from the ground (starting from the 5th)

  • Simultaneously, interphalangeal joints are forcible extended by the extensor muscles

    • During final moments of propulsion, interphalangeal joints flex slightly

  • When the heel lifts, [what] dorsiflexes the digits into the ground 

GRF

Midtarsal Joint

• Supination about the OMTJ
  

  • meaning plantarflexion & adduction of the forefoot on the rearfoot

  • Helped by [what muscles?] 

  • Due to:

    • Lateral to medial loading of the forefoot

    • External rotation of the leg

  • Reason:

    • Helps keep metatarsals (especially the 4th and 5th) in contact with the ground for a longer time

intrinsic muscles 

Midtarsal Joint

• Supination about the OMTJ
  

  • meaning plantarflexion & adduction of the forefoot on the rearfoot

  • Helped by intrinsic muscles 

  • Due to:

    • [...]

    • [...]

  • Reason:

    • Helps keep metatarsals (especially the 4th and 5th) in contact with the ground for a longer time 

• Lateral to medial loading of the forefoot

• External rotation of the leg

Midtarsal Joint

• Supination about the OMTJ
  

  • meaning plantarflexion & adduction of the forefoot on the rearfoot

  • Helped by intrinsic muscles 

  • Due to:

    • Lateral to medial loading of the forefoot

    • External rotation of the leg

  • Reason:

    • [...] 

• Helps keep metatarsals (especially the 4th and 5th) in contact with the ground for a longer time 

Midtarsal Joint

• [...] to [...] loading
  

  • Why? We need the hallux (located medially) in order to propel!

  • Due to the Peroneal muscles (both longus and brevis) lifting the lateral side of the forefoot to transfer weight medially

Lateral to medial

Midtarsal Joint

• Lateral to medial loading
  

  • Why? [...]

  • Due to the Peroneal muscles (both longus and brevis) lifting the lateral side of the forefoot to transfer weight medially

We need the hallux (located medially) in order to propel!

Midtarsal Joint

• Lateral to medial loading
  

  • Why? We need the hallux (located medially) in order to propel!

  • Due to the [what muscles] lifting the lateral side of the forefoot to transfer weight medially

Peroneal muscles (both longus and brevis)

Peaking GRF

• Weight borne of the foot [related to body weight?]

• Weight borne of the foot is borne only by the balls of the foot and toes due to the heel being lifted from the ground 

exceeds total body weight by about 125%

Peaking GRF

• Weight borne of the foot exceeds total body weight by about 125%

• Weight borne of the foot is borne [where?] 

• only by the balls of the foot and toes due to the heel being lifted from the ground 

Propulsion Duration

• Begins with: [...]

• Ends with: [...]

• Occupies 33% of the stance phase

• heel off of the observed limb

• toe off of the observed limb

Propulsion Duration

• Begins with: heel off of the observed limb

• Ends with: toe off of the observed limb

• Occupies [...]% of the stance phase

33

Propulsion Primary Events

• Subtalar [...]

• Midtarsal Joint
  

  • [...] about the OMTJ

  • [...] about the LMTJ

• 1st Ray [...]

• Metatarsal Phalangeal [...]

• [...] GRF

• Hip [...]

• Knee [...]

• Ankle [...]

• [...] Limb rotation 

• Supination

• Supination about the OMTJ

• Pronation about the LMTJ

• Plantarflexion

• Dorsiflexion

• Peaking

• flexion

• flexion

• plantarflexion

• External

Propulsive function of the foot

• Normal propulsive function requires toes to be [...]

• For digits to be stable, metatarsals must be stable & for metatarsals to be stable:
  

  • Lock the LMTJ by pronating it before heel off

  • Supinate the OMTJ after heel off to keep the metatarsals on the ground

held firmly against the ground

Propulsive function of the foot

• Normal propulsive function requires toes to be held firmly against the ground

• For digits to be stable, metatarsals must be stable & for metatarsals to be stable:
  

  • Lock the LMTJ by pronating it [when?]

  • Supinate the OMTJ [when] to keep the metatarsals on the ground 

• before heel off

• after heel off

Propulsive function of the foot

• Subtalar and OMTJ supination causes [...] between the bones of the midfoot in order to create a rigid structure for propulsion
  

  • Transverse arch angle becomes much more acute in a supinated STJ and increases in height

transverse compression

This will cause transverse arching of the lesser tarsus and bases of the metatarsals (to maintain medial column stability)

Propulsive function of the foot

• Subtalar and OMTJ supination causes transverse compression between the bones of the midfoot in order to create a rigid structure for propulsion
  

  • Transverse arch angle becomes much more [...] in a supinated STJ and increases in [...]

• acute

• height  

This will cause transverse arching of the lesser tarsus and bases of the metatarsals (to maintain medial column stability)

Subtalar Supination

• Supination continues into the propulsive period

• Just prior to toe off, there is a slight pronation (due to [...]) but the position is still supinated despite pronation for a little bit 

shift from low gear to high gear

The [...] serve as a stable bone against which the hallux can be stabilized to be a weight bearing segment 

first metatarsal

Weight Transference

• During propulsion, center of gravity is shifted to the opposite foot

• How?
  

  • [...]

• For weight transfer to occur, we must have a pronated LMTJ

• Peroneal muscles: shift weight across the forefoot from lateral to medial and then to the opposite foot which is in its contact period of the stance phase

Weight Transference

• During propulsion, center of gravity is shifted to the opposite foot

• How?
  

  • Peroneal muscles: shift weight across the forefoot from lateral to medial and then to the opposite foot which is in its contact period of the stance phase

• For weight transfer to occur, we must have a [...] LMTJ 

pronated