Muscles of Lower Extermities

What is the Lower-Extrm

• Thigh

• Leg

• Foot

What multiarticular / biarticular muscle?

Psoas Major

• Multi-articular; orginates from lumbar spine - acts on hip

What multiarticular / biarticular muscle?

Sartorius

O: Anterior Superior Iliac Spine

I: Anteromedial Tibial Condyle (pes anserine)

A: Flexion, Abduction, External rotation of femur (femoracetabular joint); Weak Flexion / Internal Rotation (when flexed) of knee/ leg

IN; Femoral Nerve

• Cross both the hip / knee joint

What multiarticular / biarticular muscle?

Rectus Femoris (Quad Group)

O: Anterior Inferior Iliac Spine (AIIS)

I: Patella (via quadriceps tendon) / tibial tuberosity; (via pateallar tendon/ligament)

A: Flexion of thigh/hip - extension of leg/knee (tibiofemoral joint)

IN Femoral Nerve

• Crosses the hip/knee - contrib to hip flexion / knee extension

• (BI-Articular quad muscle)

What is the Fascial / Tendinious Strcuture of Knee / Thigh

Iliotibial (IT) Band / Tract

• Dense band of fascia running along the lateral thigh from hip to knee (superficial - vastus lateralis) contrb to lateral staibility of hip / knee

• Attachments: Recivies fibres from Glutues Maximus / Tensor Fascia Lata - inserts distally at Gerdys Tubercle on ANterolateral Tibia

What is the Fascial / Tendinious Strcuture of Knee / Thigh

Attachment

What is the Fascial / Tendinious Strcuture of Knee / Thigh

Pes Anserine (‘gosse foot’)

• Shared tendon on upper inner > anteromedial tibia formed by Sartorius / Gracilis / Semitendinosus Muscles

• Assists in Medial Knee Stability (secondary restraint to valgus forceses)

What Anterior Hip Muscle? (COVERED?)

• Iliospoas

• Sartorius’'

• Pectineus

What Medial Hip Muscles? (COVERED)?

• Gracialis

• Adductor Brevis

• Adductor Longus

• ADductor Magnus

What Posterolateral Hip Muscles (COVERED?)

• Glutues Maximus

• Gluteus Medius

• Gluteus Minimus

• Tensor Fascia Lata

• Priformis

• Gemellus Superior / Inferior

• Obturator Femoris

Anterior Hip Muscles

Iliopsoas

O; Psoas major; Bodies; transverse processes / discs of t12-l5

Iliacus; Iiliac fossa

I; lesser trochanter of femur

A; flexion / external rotation of femur (femoroactabular joint)

IN; Femoral Nerve

• most diffentiate psoas major / iliacus / iliopsoas

Anterior Hip Muscles

Pectineus

O: Superior Ramus of Pubis

I: Pectineal Line of Femur

A: Flexion / Adduction of Femur (Femoracetubular Joint)

IN; Femoral Nerve

Medial Hip Muscles

Gracilis

O: Pubis

I: Anteromedial Tibial Condyle (pes anserine)

A: Adduction of Femur (femroactebular joint); weak flexion / interal roatation (when flexed) of knee/leg

IN; Obturator Nerve

• Cross both the hip / knee joints > knee actions

• (Notes) part of Pes anserine (Distal tendons of sartorius / gracilis / semitendinosus coverage @ proximal / medial / anterior tibia/ apears as a goose foot

Medial Hip Muscles

Adductor Longus

O: Pubis

I: Linea Aspera (Middle Portion)

A: Adduction / Flexion of Femur (Femoractebular Joint)

In; Obtruator Nerve

Medial Hip Muscles

Adductor Brevis

O: Pubis

I: Linea Aspera (middle portion)

A: Adduction / Flexion of Femur (femoractebular joint)

In; Obtruator Nerve

Medial Hip Muscles

Adductor Portion

O: Inferior Pubic Ramus , Ischial Ramus

I; Gluteal Tuberoisty / Entire length of linea aspera / medial supracondylar line

A; Adduction / Flexion of Femur (femoroacetabular joint) - stabilzing hip rotation

In; Obturator Nerve

Medial Hip Muscles

Hamstring (ischiocondular) portion

O: Ischial Tuberosity

I: Adductor Tubercle of Femur

A: Adduction / Extension of Femur (femoroactevular joint) ; stabiling hip rotation

IN; Sciatic Nerve

Posterior / Lateral Hip Muscles

Gluteus Maximus

O: Posterior Gluteal Line / Sacrum / Coccyx / Lumbar Fascia

I: Gluteal Tuberosity / Iliotibial band

A: Ext / External rotation of femur (femoroacetabular joint) ; tension iliotibial band

Superior Fibres; Abduction of Femur

Posterior / Lateral Hip Muscles

Gluteus Medius

O: Ilium between posterior / middle (anterior) gluteal lines

I: greater trochanter (lateral aspect)

A; Abduction / internal rotation of femur (femoracetabular joint) pelvic stabilization

posterior fibres; external rotation of femur

In; Superior Gluteal Nerve

Posterior / Lateral Hip Muscles

Gluteus Minimus

O: Iliium between middle (anterior) / inferior gluteal lines

I: Greater trochanter (anterior aspect)

A: Abduction / Internal Rotation of Femur (femoroacetabular joint) - pelvic stabilization

In; Superior Gluteal Line

Posterior / Lateral Hip Muscles

Tensor Fascia Lata (TFL)

O; Anterior Iliac Crest (immediatiely posterior to ASIS)

I; Iliotibial Band

A; Abduction / Flexion and Internal rotation of Femur (femoroacetabular joint; Tensions Iliotibial band

In; Superior Gluteal Nerve

Deep Hip External Rotators

Priformis

O: Anterior Sacrum

I: Greater Trochanter

A: External rotation of Femur when Extended; Abduction of Hip/Thigh when flexed; (femroactebular joint)

Deep Hip External Rotators

Gemellus Superior

O; Ischial Spine

I; Greater Trochanter

A; External Rotation of Femur when Extended; abduction of hip/thigh/femur when flexed

Deep Hip External Rotators

Obturator Internus

O: Inner (posterior) surface of obturator membrane (and boundaries of obturator forearm)

I: Greater Trochanter

A: External Rotation of Femur when extended (abduction of hip/thigh/femur when flexed

Deep Hip External Rotators

Gamellus Inferior

O: Ischial Tuberosity

I: Greater Trochanter

A: External Rotation of Femur when Extended; Abudction of hip/thigh/femur when flexed

Deep Hip External Rotators

Obturator Externus

O: Outer (anterior) surface of obturator membrane (and boundaries of obturator foramen)

I: Trochanter fossa of Femur

A: External rotation of Femur when extended; Abuction of hip/thigh/femur when flexed

In; Obturator Nerve

Deep Hip External Rotators

Quadtratus Femoris

O: Ischial Tuberosity

I: Intertrochanteric Crest of Femur

A: External Rotation of Femur

Deep Hip External Rotators

Adductor Magnus

• Adductor / Hamstring / Ischiocondylar Portions

Deep Hip External Rotators

Hamstring (Ischiocondylar) Portion

O: Inferolateral aspect of the ischial tuberosity (the "sit bone").

I: Adductor tubercle on the medial condyle of the femur, with some fibers attaching to the medial supracondylar line

A: Extension of the hip (thigh). It also acts as a powerful adductor of the hip joint.

Posterior / Lateral Hip Muscle

Gluteus Maximus

O: Posterior Gluteal Line, Sacrum, Coccyx, Lumbar Fascia

I; Gluteal Tuberosity, Illiotibial Band

A; Ext / external rotation of femur (femoroactabular joint) - tension iliotibial band

Superior Fibres - Abduction of Femur

Inferior Fibres - Adduction of Femur

In; Inferior Gluteal Nervef

Posterior / Lateral Hip Muscle

Gluteus Medius

O: The external surface of the ilium (between the iliac crest and the posterior/anterior gluteal lines) and the gluteal aponeurosis. [1, 2]

I: The lateral surface of the greater trochanter of the femur.

A: Abducts the hip (moves the leg away from the midline). Anterior fibers assist with hip flexion and internal rotation; posterior fibers assist with hip extension and external rotation. It is also the primary stabilizer of the pelvis when standing on one leg

Posterior / Lateral Hip Muscle

Gluteus Minimus

O: The external surface of the ilium (the large, broad part of your pelvic bone), specifically in the space between the anterior and inferior gluteal lines

I: The anterior facet of the greater trochanter of the femur (the bony bump on the upper/outer part of your thigh bone) and the anterosuperior hip joint capsule. [1]

A: Hip Abduction: Moves the thigh outward, away from the body's midline.

• Medial Rotation: Rolls or rotates the thigh inward.

• Pelvic Stabilization: Crucial for walking and standing; it keeps the pelvis level and prevents it from sagging to the opposite side when you stand on one leg. [1, 2, 3, 4]

Posterior / Lateral Hip Muscle

Tensor Fascia Lata (TFL)

O; Anterior Illiac Crest (immeditaelu posterior to asis_

I Iliotibial band

A; Abduction / flexion and internal rotation of fmeur (femoroactebular joint); tension iliotibial band

IN; Superior Gluteal Nerve

Deep Hip External Rotators (Deep Six)

Priformis

O: Anterior (pelvic) surface of the sacrum, the gluteal surface of the ilium near the greater sciatic notch, and the sacrotuberous ligament.

I: Superior border of the greater trochanter of the femur.

A: Laterally rotates the extended thigh and abducts the flexed thigh. It also acts to stabilize the hip joint. [1, 2, 3, 4]

Deep Hip External Rotators (Deep Six)

Gemellus Superior

O: The outer/gluteal surface of the ischial spine of the pelvis.

I: The medial surface of the greater trochanter of the femur, merging into a common tendon with the obturator internus muscle

A: It acts to externally (laterally) rotate the extended thigh and abducts the thigh when the hip is flexed. It also stabilizes the hip joint by keeping the femoral head securely in the socket.

Deep Hip External Rotators (Deep Six)

Obturator Internus

O: Inner (posterior) surface of obturator membrane / boundaries of obturatr foramen

I: greater trochanter

A: External Rotation of Femur when Extended - Abduction of hip/thigh/femur when flexed

Deep Hip External Rotators (Deep Six)

Gemllus Inferior

O; Ischial Tuberoisity

I; Greater Trochanter

A; External Rotation of Femur when Extended - Abduction of hip/thigh/femur when flexed

Deep Hip External Rotators (Deep Six)

Obturator Externus

O: Outer surface of the obturator membrane and the bony margins of the obturator foramen (on the pubis and ischium).

I: (Insertion): Trochanteric fossa of the femur.

A: Primarily externally (laterally) rotates the thigh at the hip joint, and also acts as an adductor of the hip (especially when the hip is flexed). [1, 2, 3, 4, 5, 6]

Deep Hip External Rotators (Deep Six)

Quadratus Femoris

O:Ischial Tuberosity

I: Introchanteric Crest of Femur

A: External Rotation of Femur

Muscles that Move the Leg?

Quadriceps Femoris

• Quadriceps Tendon

• Patellar Tendon / Ligament

Muscles that Move the Leg?

Rectus Femoris

O: Anterior Inferior Iliac Spine (AIIS)

I: Patella (via quadriceps tendon) / tibial tuberosity; (via pateallar tendon/ligament)

A: Flexion of thigh/hip - extension of leg/knee (tibiofemoral joint)

IN Femoral Nerve

Muscles that Move the Leg?

Vastus Lateralis

O: Greater Trochanter / Lateral lip of Linea aspera

I: Patella (quad tendon) / tibial tuberosity - (patelar tendon / ligament)

IN: Femoral Nerve

A: Extension of leg/knee (tibiofemoral joint)

(Common intramuscular injecion site in infants - vaccinations)

Muscles that Move the Leg?

Vastus Medialis

O: Interochanteric line / medial lip of linea aspera / medial supracondylar ridge

I; Patella (via quadtriceps tendon) / tibial tuberosity (via patellar tendon/ligament)

A: extension of knee/leg (tibiofemoral joint)

In; Femoral nerve

Muscles that Move the Leg?

Vastus Intermedius

O: Anterior Femur

I: Patella (via quadriceps tendon) / tibial tuberosity (via patellar tendon/ligament)

A: Extension of leg/knee - tibiofemoral joint

In; Femoral Nerve

• Deep to Rectus Femoris

What muscle? (posterior thigh)

Hamstrings

• Biceps Femoris

• Semitendinosus

• Semimembranosus = cross the hip / knee - contrb to hip extension / knee flexion

• Short head of Biceps Femoris > (Monoarticular) @ knee

• (Three muscles of posterior thigh that act as prime movers of knee flexion / tg with gluteus maximus - hip extension (short head of biceps femoris is monoarticular / acts only at knee

What muscle?

Biceps Femoris (long / short heads)

O: Long Head; Ischial tuberosity / Short Head; Linea asperia (distal) / lateral supracondylar ridge

I: Head of Fibula

A: Flexion of Knee/Leg / External Rotation of Knee / Leg when Flexed

Long head: extension of Hip/Thigh / External rotation of hip/thigh

IN: Sciatic nerve

What muscle?

Semimembranosus

O: Ischial tuberosity

I: medial condyle of tibia

A: flexion of knee/leg / interal rotation of knee/leg when flexed / extension of hip/thigh

In; Sciatic Nerve

What muscle?

Semitendinosus

O: Ischial Tuberosity

I: Medial Condyle of Tibia

A: Flexion of knee/leg / internal rotation of knee/leg when flexed / extension of hip /thigh ; internal rotation of hip/thigh

IN; Sciatic Nerve

What muscle?

Popliteus

O: Lateral Femoral Condyle / Posterior horn of lateral meniscus

I: Posterior Tibia (superior to soleal line)

A: Flexion / Internal rotation of knee/leg (unlocking the fully extended knee okc)

IN Tibial Nerve

What is Knee Locking / Unlocking

Screw-Home Mechnaism (SHM)

• Largely passive locking mechanisms that occur during the final -20 degrees - of stability whie reducing muscular effort during standing

OCCURS as the quads extend the knee into terminal extension - tibia/femur rotate relative to one another - prod a locked pos

Popliteus activiely unlocks the knee to intitate flexion

mechanis is esp important during actitivies such as walking, where the knee alternatives between stability (locked) / mobility (unlocked)

Knee Locking / Unlocking

Non-weight Bearing (OKC)

• Tibia externally (Laterally) rotates on fixed femur

Knee Locking / Unlocking

Weight Bearing (CKC)

• Tibia is fixed / Femur internally (medially) rotates on tibia

What is occuring

Unlocking The Knee (popliteus muscle)

Knee Locking / Unlocking (poplitues muscle)

Weight-bearing (CKC)

• Tibia is fixed - so poplitues externally rotates the femur on fibia

What is the Anterior Comp

• Tibialis Anterior

• Extensor Digitorum Longus

• Extensor JHallucis Longus

What is Lateral Comp

• Fibularis

• Peroneals

What Post Comp

Superficial - Gastrcenemius / Soleus / Plantaris

What post comp

Deep - Tibialis Posterior / Flexor Digitorum Longus / Flexor Hallucis Longus

What Anterior Comp Muscle

Tibialis Anterior (Anterior Comp)

O: Anterolateral Tibia

I: Plantaar aspect of 1st metatarsal and medial cuneiform

A: Dorsiflexion (Talocrual Joint) and inversion / subtalar and intertarsal joints - of anke/foot

In; Deep peroneal nerve

What Anterior Comp Muscle

Extensor Hallucis Longus

O: Middle / Anterior Fibula

I: Dorsal Aspect of Distal Phalanx of great (1st) toe / hallux

A; Extension of Great toe / hallux (mtp / ip joints) dorsiflexion of ankle / talocural joint

IN; Deep peroneal nerve

What Anterior Comp Muscle

Extensor Digitorum Longus

O: Proximal ½ of anterior fibula / lateral tibial condyle / proximal interoseous membrame

I: Dorsal Aspect of middle / distal phalanges - 2nd/5th toes (4 seperate tendons)

A: Extension / toes/digits 2/5 (mtp / ip joints); dorsiflexion of ankle (talorcrual joint)

In; Deep peroneal nerve

• Small muscle called Peroneus Tertilis exists in the digital anterior compartment (not req to know)

What Lateral Comp Muscle

Peroneus Longus (Fibularis Longus)

O; Proximal 2/3 of lateral fibula

I; Plantar aspect of 1st metatarsal / medial cuneiform

A; Eversion of ankle/foot (subtalar / intertarsal joints) ; plantarflexion of ankle (talocrual joint)

In; superfiical peronael nerve

(important muscle for supporting arches of foot)

What Lateral Comp Muscle

Peroneus Brevis (Fibularis Brevis)

O: Distal 2/3 of Laterral Fibula

I Base of 5th metatarsal

A; Eversion of ankle/foot (subtalar / intertarsal joints) / plantarflexon of ankle (talocrual joint)

IN: Superfical peroneal nerve

What posterior comp muscle

Gastrocenemius (Superficial)

O; Posterior aspectof medial / lateral femoral condyles

I; Calcaneus (via Achilies Tendon)

A; Plantarflexion of Ankle/foot (talocrural joint); Flexion of leg/knee (tibiofemoral joint)

What posterior comp muscle

Superfifical

Soleus

• O - Proximal aspect of medial / lateral femoral condyles

  I - Calcaneus (achiles tendon)

  A - Plantarflexion of ankle/foot (talocrual joint)

• In; Tibial Nerve

What posterior comp muscle

Superfiical

• Gastrocenemius

O; Posterior aspect of medial / lateral femoral condykle

I; Calcaneus (achillies tenon)

A; Plantarflexion of ankle/foot (talocrual joint)

in; tibial nerve

What Tendon

Achileies Tendon

What is Deep Posterior Muscle

Tibialis Posterior

O; proximal posterior tibia and fibula

I; Calcaneus / navicular tuberoisty / cuboid / all cunniforms and metatarsals 2/4

A; Plantarflexion (talocrual joint) / inversion (subtalar / intertarsal joints) of ankle/foot

In; Tibial neve

What is Deep Posterior Muscle

Flexor Digitorum Longus

O; Posterior Tibia (Inferior-to soleal line)

I; Plantar aspect of distal phalanges pf 2nd/5th toes/digits - 4 sep tendons

A; Flexion of 2nd/5th toes (mtp/ip joints); Plantar flexion of ankle/foot (talocrual joint)

In; Tibial Nerve

What is Deep Posterior Muscle

Flexor Hallucis Longus

O; Distal 2/3 posterior fibula

I; Disltal phlanx of great 1st toe/hallux

A; Flexion of great toe/hallux (mtp / ip joints); plantarflexion of ankle/ foot (talocrural joint)

IN; Tibial nerve

IMPORTANT FOR SUPPORTING ARCH FOR FOOT

How many Intrinsic Muscles of Foot

19 Muscles are located entirely within the foot

What nerve / Innervation

Superior Gluteal nerve - supplies lateral hip muscles - important for pelvic stability during gait - exits the pelvis - superior - prirformis

• Glutues medius, minimus, tensor fascia lata

What nerve / Innervation

Inferior Gluteal Nerve - Supplies primary gluteal hip extensor ; exists the pelvis inferior - priroformis

• Gluteus Maximus

What nerve / Innervation

Femoral Nerve

• Iliopsoas (via branches)

• Sartorius

• Pectineieus (partailly

• quadriceps femoris

What nerve / Innervation

Obturator Nerve

• adductor longus

• adductor brevis

• adductor magnus

• gracilis

• obturator externus

What nerve / Innervation

Sciatic Nerve

• Hamstrings (bipceps femoris - long head, semitendinosis, semimembranosus)

• hamstring portion - adductor magnus

What nerve / Innervation

Tibial Nerve

• Posterior Leg (superfifical) ; Gastrocenmous, soleus, plantaris

• Posterior leg (deep); Tibialis posterior, flexor digitorium longus, flexor hallucis longus

• plantar foot - (medial / lateral plantar nerves) - most intrinisic foot muscles

What nerve / Innervation

Common Fibular (Peroneal) Nerve

• no innervatio

What nerve / Innervation

Deep Fibular (peroneal) nerve

• Tibialis Anterior

• Extensor Digitorum Longus

• Extensor Hallucis Longus (anterior leg)

Dorsal Foot

• Dorsal foot intrimsic muscles - (extensor digitorum brevis, extensor halllucis brevis)

What nerve / Innervation

Superficial Fibular (Peroneal) Nerve

• Fibularlis (peroneus) longus

• Fibularis (peroneus) brevis - (lateral leg)

Pathophysiology

Hamstring Strain

Pathophysiology

Patellar Tendinopathy (Jumpers knee)

Pathophysiology

Achilles Tendinopathy

How many intrinsic muscles of the foot?

19 Muscles located entirely within the foot; (Origin / inserition within the foot)

What muscle (superfical postrior comp)

Plantaris

• O - Lateral Supracondylar ridge of femur

• I Posteromedial calcaneus of may joint achillies tendon

• Plantarflexion of ankle/foot (talocrural joimt) weak flexion of knee leg

• In tibial nerbe

(NOT EVERYONE HAS A PLANTARIS MUSCLE)

What os the Flexion of Proximal Phalanx MCP Joint ; with Simutaneoues Extension of Dstal / Middle Phalange? (MUSCLE)

Lumbricals

Lumbricals ½ - Median Nerve

Lumbricals ¾ - Ulnar Nerve

Abduction of D2/D5 - (MCP Joints) WHAT MUSCLES

Dorsal Interosseal - Ulnar Nerve

Adduction of D2/D5 - (MCP Joints) WHAT MUSCLES

Palmar Interossei - Ulnar Nerve

Flexor of Pollex (Cmc / MCP / IP joints)

• Flexor Pollcis Longus - Median Nerve

• Flexor Pollcis Brevis - Median Nerve

Extension of pollex (CMC / MCP / IP JOINTS)

• Extensor Pollcis Longus

• Extensor Pollcis Brevis

• Abductor Pollcis Longus = Radial Nerve

Ext of Pollex

CMC / MCP / IP JOINTS

Adductor Pollicis Longus - Radial Nerve

Adductor Pollicis Brevis - Median nerve

Adduction of Pollex (CMC JOINT)

Adductor Pollcis - Ulnar Nerve

Flexion of Leg / Tibia at Knee / Tibiofemoral Joint

Biceps Femoris - Sciatic Nerve

Semtindonosus - Sciatic Nerve

Semimebranosis - Sciatic Nerve

Gastrocenmeius - Tibial Nerve

(Sartorius / Gracialis / Plantaris - not req)

Extension of Leg / Tibia at Knee / Tibiofemoral Joint

Rectus Femoris

Vastus Medialis

Vasus Lateralis

Vastus Intermedius

= Femoral Nerve (ALL)

Internal Medial of Leg / Tibia at Knee / Tibiofemoral Joint

Poplitues - Tibial Nerve

Semitiendinosus - Sciatic Nerve

Semimebranosus - Sciatic Nerve

External lateral rotation of Leg / Tibia at Knee / Tibiofemoral Joint

Biceps Femoris

• Sciatic Nerve

Movement of Ankle / Foot

(Talocurual Joint): Dorsiflexion

• Tibialis Anteiror

• Syntergists (WEAKER CONTRIBUTION):

• Tibialis Posterior, Flexofr Digitorum Longus, Flexor Hallcius Longus

Inversion

(Subtaar Joint)

WHAT MUSCLES?

• Tibialis Anterior (When ankle is in dorsiflexion) - Deep peroneal Nere

• Tibialis Posterior (Ankle in Plantarflexion) - Tibial Nerve

Eversion Subtalar Joint

What muscles

• Peroneus Longus

• Peroneous Brevis

• Superficial Peroneal Nerve

How many intrincsic muscles?

• 19 muscles located entirely within the foot

• 17 arranged into 4 plantar layers - superficial to deep

FUNCTIONS:

• Flexion, ext, abd, add of toes - (digits of foot)

• Maintain foot aignment, biomechaniachs proprioception / bal

• stabilze / maintain tendons of extrinsic muscles thro direct atchment / bleding w them

• support arches of foot - working with extrinsic muscles such as tinailis posterior fibularis, flexor hallucis longus