INTRINSIC M COMPARTMENT (PERIODS) Flashcards
Stabilize the midtarsal joint by pronating the OMTJ early in propulsion
Reinforces the extensor expansion by assisting the lumbricales and the EDL as they extend the 2nd, 3rd, and 4th toes
Stabilize the 2nd, 3rd and 4th metatarsals against the lesser tarsus posteriorly
Assist with posterior stability of the 2nd, 3rd, and 4th toes against the respective met heads and the phalanges posteriorly
Extensor Digitorum Brevis M.
PROPULSION
Stabilize posteriorly the first metatarsal against the lesser tarsus
Extensor Hallucis Brevis M.
MIDSTANCE
Stabilize posteriorly the first metatarsal against the lesser
tarsus
Stabilize posteriorly the hallux against the first metatarsal
Assist in developing adduction stability of the hallux at the first MPJ
Extensor Hallucis Brevis M.
PROPULSION
Extend the intermediate and distal IPJs of the lesser toes
Lumbrical M.
MIDSTANCE
Extend the intermediate and distal IPJs of the lesser toes
Assist in stabilizing the proximal phalanx of the lesser toes in a plantarflexed direction against vertical GRFs
Provide slight adduction stability of the proximal phalanx of the lesser digits resisting abduction force of GRFs
Lumbrical M.
PROPULSION
No action
May serve as antagonist muscle to EDL
Lumbrical M.
SWING
Stabilize the bases of the lesser four proximal phalanges posteriorly against the corresponding met heads
Stabilizes the bases of the proximal phalanges transversely, providing adductor/abductor
stability at the MPJ
May assist in the function of the extensor expansion
Plantarflexory force on the proximal phalanx
Interossei M.
PROPULSION
Stabilize the hallux in ADDUCTION
Assist with posterior stability of the proximal phalanx of the hallux against the ground
Stabilize the OMTJ axis by supinating the forefoot about the axis
Plantarflex the first ray and stabilize the first met head against the ground
Abductor Hallucis M.
PROPULSION
Stabilize the hallux in ABDUCTION
Help stabilize the proximal phalanx of the hallux posteriorly against the first met head
Plantarflex the base of the proximal phalanx stabilizing the hallux against GRFs
Adductor Hallucis M.
PROPULSION
Prevent elongation of the deep transverse intermetatarsal ligament
Provides transverse stabilization to the forefoot at the level of the MPJs
Transverse Pedis M.
PROPULSION
Stabilize the base of the proximal phalanx of the hallux against the ground
Stabilize the base of the proximal phalanx of the hallux posteriorly against the
first met head
Assists the FHL to stabilize the hallux against the ground
Assists with posterior stability of the 1st, 2nd, and 3rd metatarsals against
their respective cuneiforms
May provide some transverse stability to the central metatarsals
Provides a more plantarflexory force on the hallux due to increased pulley at
the 1st MPJ
Flexor Hallucis Brevis M.
PROPULSION
Contracts at heel lift and throughout propulsion
***OMT supination = adduction and plantarflexion
Stabilize the OMTJ by supinating it against GRF directed against the lesser met heads
Stabilizes the 2nd, 3rd, 4th and 5th rays posteriorly and plantarly
Assists the FDL in maintaining stability of the lesser digits against the ground
Stabilizes the intermediate phalanx of each toe posteriorly against the proximal phalanx
and the proximal phalanx against the met head
Flexor Digitorum Brevis M.
PROPULSION
Stabilizes the midstarsal joint about the OMTJ axis
Assists with posterior stabilization of the lesser mets, 2nd and 3rd cuneiform and cuboid
Quadratus Plantae M.
MIDSTANCE
Stabilizes the midstarsal joint about the OMTJ axis
Provides stability to the FDL tendon slips to the toes while simultaneously providing stability to the origin of the lumbricals
Provides posterior and lateral tension on the FDL tendon slops neutralizing the natural posterio-medial pull of the FDL. Allows a straight posterior pull on the digits
Assists with posterior stabilization of the lesser mets, 2nd and 3rd cuneiform and cuboid
Quadratus Plantae M.
PROPULSION
Provides mostly posterior stabilization due to the small pulley available at the 1st MPJ
Flexor Hallucis Brevis M.
MIDSTANCE
