Kinesiology - Lower Extremity

Ilium

Largest and uppermost portion of pelvic girdle. It articulates with sacrum posteriorly

-Sacroiliac joint

Ischium

Lowest portion of pelvic girdle

Pubis

Anterior portion of pelvic girdle

Acetabulum

Formed by all three bones the innominate.

Articulation site b/wn femur and coxa - Hip joint or coxofemoral joint. It articulates with femoral head laterally.

-Coxofemoral joint (hip joint)

Obturator Foramen

Largest foramen in the body. It is formed by the ischium & pubis.

Sciatic Nerve

Emerges from lumbosacral plexus. It travels through greater sciatic foramen and forms the nerves: Tibial & common perineal nerves

Pelvic Girdle

Provides support to the body's weight (trunk/core)

Provides articulation sites LE limbs

Provides attachment sites for LE musculature

Provides protection for lower quadrant organs: bladder, reproductive organs, distal large intestine

Femur

Longest & strongest bone in the body

Head: Articulates w/ acetabulum in fovea capitis.

Neck: Frequent location for fractures.

Greater trochanter: superior, lateral

Lesser trochanter: inferior, medial

Intertrochanteric crest

Fovea Capitis

Depression in the femoral head that serves as attachment for ligamentum teres

Patella

Sesamoid bone ("free-floating") that improves leverage of quadriceps & their ability to extend knee.

Embedded within the quadriceps (above) & patellar tendon (below)

Patellar tendon

Continuation of the quadriceps tendon

Tibia

Shin bone

Proximal end is expanded into 5 parts

Distal end form into Medial malleolus

Fibula

Proximal end: head

Distal end: lateral malleolus - limited weight-bearing during movement.

Pes Anserine

Located on the anterior, superior and medial aspect of the tibia just below the knee joint line.

It is the location of the insertion of 3 important muscles: Sartorius, Gracilis and Semitendinosus

It is latin for "Goose foot."

Menisci

Semilunar cartilages attached to tibial plateau - Medial ("C" shaped), Lateral ("O" shaped)

Only 3-5 mm thick on average

Functions: Improves stability of tibiofemoral joint (increases radius of curvature of the tibial condyles thereby increasing congruency)

Absorbs shocks (distributes weight bearing forces)

Medial is more firmly attached than the lateral.

Red Zone

Part of meniscus that is highly vascular (blood supply)

Red-white Zone

Part of meniscus that has mild vascularity

White Zone

Part of meniscus that is avascular (no blood supply)

Genu Varum

"bowleg" knee alignment

Genu Valgum

"Knock knees" knee alignment

Genu Recurvatum

"Hyperextension" knee alignment

Talus

Articulates with tibia & fibula (Forms ankle)

Calcaneus

Largest tarsal bone (heel) weight bearing bone

Navicular

Medial bone of foot

Cuboid

Lateral bone of foot

Cuneiforms

Lateral, intermediate, and medial bones in the foot

Metatarsals (5)

Form the arches of foot with ligamentous and muscular support

Phalanges (14)

Each toe has three (proximal, middle, distal) except big toe/1st digit

1st digit only has a proximal and distal phalanx

Coxa (innominate)

Articulates with contralateral coxa anteriorly

-Pubic symphysis

Pubic Symphysis

Cartilaginous (amphiarthrotic) joint - allows for minimal movement

Coxa articulates w/ contralateral coxa anteriorly

Interpubic disc: lies b/wn bilateral pubic bones (disc and bilateral body of pubis form joint)

Interpubic Disc

Lies b/wn bilateral pubic bones (disc and bilateral body of pubis form joint)

Sacroiliac (SI) Joint

Nearly immoveable joints on the lateral aspect (auricular surfaces) of the sacrum. It is supported by the anterior & posterior sacroiliac ligaments, the sacrotuberous ligament, and the sacrospinous ligament.

Ilium articulates w/ sacrum posteriorly

Anterior Sacroiliac Ligament

Anterior sacrum to anterior ilium ligament

Posterior Sacroiliac Ligament

Posterior sacrum to posterior ilium ligament

Sacrotuberous Ligament

Sacrum to ischial tuberosity ligament

Sacrospinous Ligament

Sacrum to ischial spine

Coxofemoral Joint

"Ball-and-socket" joint - more stable than shoulder joint

Articulation b/wn femoral head and periphery of acetabulum (lunate surface) laterally

Acetabular fossa is non-articulating

Ligaments provide support for joint

Acetabular labrum & musculature also provide stability

Ligamentum Teres

Ligament of the head of the femur, also called Round Ligament

Travels from fovea captitis to the acetabulum

Normal = no tension in ligament

Primary function of carrying blood supply to/from the head of femur

Acetabular Labrum

Fibrocartilage ring attached to margin of acetabulum.

Enhances joint stability by: Free end of labrum extends beyond the equator of head of femur & deepens the acetabulum, acts as a seal to maintain negative intra-articular pressure, & helps hold the head of femur into the acetabulum

Transverse Acetabular Ligament

Forms inferior aspect of labrum and helps maintain position of the femoral head in the acetabulum

Avascular Necrosis

Generally occurs in neck of femur; the blood supply is cut off

Osteoarthritis

Breakdown of cartilage

Iliofemoral

Strongest ligament in the body, Y-shaped; ligament of coxofemoral joint. It helps stabilize jointing the upright position & limits hyperextension (Anterior)

Pubofemoral

Ligament of coxofemoral joint that limits abduction (Anterior)

Ischiofemoral

Ischium to edge of greater trochanter that limits medial rotation (Posterior) (It is the only ligament that attaches to the greater trochanter)

Patellofemoral Joint

Articulation with patellar surface of femur

Lateral Collateral Ligament (LCL)

Attachments: lateral epicondyle of femur, head of fibula which prevents adduction of lower leg

Medial Collateral Ligament (MCL)

Attachments: Medial epicondyle of femur, medial tibia that prevents abduction of lower leg and has deep fibers that are fused w/ medial meniscus (intracapsular)

Anterior Cruciate (ACL)

Attachments: Anterior intercondylar area of tibia to the posterior medial aspect of the lateral condyle of the femur

Function: Primary restraint of anterior displacement of tibia on the femur

Posterior cruciate (PCL)

Attachments: Posterior intercondylar area of tibia to lateral aspect of the medial condyle of the femur

Function: Primary restraint of posterior displacement of tibia on the femur

Tibiofibular Joints

Formed by the articulation between the tibia and fibula.

Proximal - Near knee

Distal - Near ankle

Syndesmosis (fibrous joint)

Distal tibiofibular joint formed by interosseous/syndemotic membrane

Talocrural Joint

Hinge joint (dorsiflexion, plantarflexion)

Articulation of tibia, fibula, & talus. It is referred to as "ankle mortise"

Talocalcaneal (Subtalar Joint)

3 Plane joints (triplanar)

Articulation of talus & calcaneus

Deltoid (medial)

Ankle ligament (medial) - very strong complex which supports talocrural and subtler joints medially

Tibial Tuberosity

Insertion site of quadriceps

Groin

Anterior aspect of the hip joint, but commonly accepted as adductor group

Iliacus

Origin: Iliac Fossa

Insertion: Lesser trochanter of femur- tendon inserts or combines with psoas major and together they have one insertion tendon

Action: Flexion of hip; anterior rotation of pelvis (anterior pelvic tilt) - w/ femur stabilized

Nerve: Femoral nerve

Femoral Nerve

Innervates the quadriceps & hip flexors

Psoas Major

Origin: T-12-L5 - vertebral transverse processes, bodies and discs

Insertion: Lesser trochanter

Action: Hip flexion - Also extension of lumbar spine pulling it into lordosis

Nerve: Femoral Nerve (L2-L4)

Iliopsoas Complex

Strong hip flexor

Over activation or tightness might lead to excessive lumbar lordosis & back pain

Sartorius

"Tailor's Muscle" - Longest muscle in body

Origin: ASIS

Insertion: Superior medial surface of tibia (pes anserine)

Action: At HIP (thigh): flexes, abducts, and laterally rotates; at KNEE: flexes and slightly medially rotates (after knee is in flexion)

Quadriceps Group

Rectus Femoris, Vastus medialis, Vastus Intermedius, Vastus Lateralis

Insertion: All 4 quads insert at tibial tuberosity

Action: Knee extension

Rectus Femoris

Most superficial

Origin: AIIS - only quadriceps muscle w/ origin on pelvis

Action: Knee extension and hip flexion - Extends across hip and knee joints so has actions at both joints

Vastus Lateralis

Largest muscle of the quads

Origin: Intertrochanteric linea, greater trochanter, & lateral lip of lines aspera

Action: Knee extension

Vastus Medialis

Origin: Intertrochanteric linea, medial lip of linea aspera

Action: Knee extension

Vastus Intermedialis

Lies deep to the rectus femuris

Origin: Anterior and lateral surfaces of upper two-thirds of femur

Action: Knee extension

Pectineus

Origin: Superior ramus of pubis

Insertion: Lesser trochanter to linea aspera of femur

Action: hip adduction & flexion

Nerve: Femoral nerve

Gracilis

Only adductor to cross hip & knee joint

Origin:Inferior ramus & body of pubis

Insertion: Superior medial surface of tibia (pes anserine)

Action: At HIP: Adduction; at KNEE: Flexion & medial rotation

Nerve: Obturator nerve (L2-L4)

Adductor Brevis

Origin: Inferior ramus of pubis

Insertion: Upper 1/3 of linea aspera

Action: Hip adduction & assists in hip flexion. It assists in hip medial (and lateral) rotation depending upon hip position

Nerve: Obturator (L2-L4)

Adductor Longus

Origin: Body of pubis

Insertion: Middle 1/3 of lines aspera

Action: Hip adduction & flexion. Assists in hip medial (and lateral) rotation depending upon hip position

Nerve: Obturator Nerve (L2-L4)

Adductor Magnus

Origin: Ischial tuberosity & inferior ramus of pubis

Insertion: Linea aspera & adductor tubercle of femur - Two portions of this large muscle

Action: Hip adduction (powerful)

Also part that inserts on line aspera = assists w/ hip flexion & lateral rotation

Also part that inserts on adductor tubercle = Assists w/ hip extension & medial rotation

Nerve: Obturator (L2-L4) - Sciatic nerve (L4-S3)

Tensor Fascia Latae

Origin: Anterior iliac crest

Insertion: Iliotibial Band

Action: Hip (thigh) flexion and abduction

Nerve: Superior gluteal nerve (L4-S1)

Along w/ Gluteus Maximus (which also attaches to IT Band) draws the IT Band upward stabilizing knee

Gluteus Maximus

Origin: Iliac crest, sacrum, & coccyx

Insertion: Gluteal tuberosity of femur and IT Band

Action: Hip extension (prime mover) and assists hip lateral rotation

Nerve: Inferior Gluteal Nerve (L5-S2)

Gluteus Medius

Origin: Outer surface of ilium (inferior to iliac crest)

insertion: Greater trochanter of femur - Portion is deep to the Gluteus Maximus

Action: Hip (thigh) abduction & medial rotation

Nerve: Superior gluteal nerve (L4-S1)

Gluteus Minimus

Deep to the gluteus medius

All the same characteristics & function as the gluteus medius

Piriformis

Pear-shaped lateral rotator of femur

Origin: Internal surface of sacrum

Insertion: Greater trochanter - crosses greater sciatic notch

Action: Hip (thigh) lateral rotation

Hip abduction (if hip is flexed).

Deep 6 (External Rotators)

Shorten to cause lateral rotation: Piriformis, Gemellus superior, Obturator externes, Gemellus inferior, Quadratus femoris

Sciatica

Compression of the sciatic nerve

Radiating or shooting pain down the leg

Hamstrings

Biceps femoris (long & short head)

Semimembranosus

Semitendinosus - Action: Knee flexion & hip extension; Nerve: Sciatic nerve

Semitendinosus

Origin: Iscial tuberosity

Insertion: Superior medial surface of tibia (pes anserine)

Action: Knee flexion & hip extension - hip medial rotation

Semimembranosus

Origin: Ischial tuberosity

Insertion: Posterior medial condyle of tibia

Action: Knee flexion & Hip extension - hip medial rotation

Biceps Femoris

Most lateral of the 3 hamstring muscles

Origin: Long head - ischial tuberosity

Short head - posterior femur (lines aspera); not a hip extender

Insertion: Fibular head, lateral condyle of tibia

Action: Knee flexion & hip extension (long head only); hip lateral rotation

Popliteus

Origin: Lateral condyle of femur

Insertion: Upper part of posterior surface of tibia

Action: Unlocks knee to allow for flexion to occur; OKC- medial rotation of tibia; CKC - lateral rotation of the femur

Extrinsic Muscles (11)

Muscles located in the lower leg but act on the feet &/or toes

Contained in 4 well-confined compartments:

Anterior (4), Lateral (2), Deep (3), Superficial (2)

Deep Peroneal Nerve

Anterior Innervation of lower leg and foot musculature

Superficial Peroneal Nerve

Lateral Innervation of lower leg and foot musculature

Tibial Nerve

Deep & superficial Innervation of lower leg and foot musculature

Tibialis Anterior

Found just lateral to the tibia: Most medial and anterior leg muscles

Origin: Shaft of the tibia

Insertion: Medial cuneiform & 1st metatarsal

Action: Dorsiflexion & Inversion

Extensor Digitorum Longus

Origin: Anterior fibula, lateral condyle of tibia

Insertion: Distal phalanx - Digits 2-5

Action: Extend digits 2-5

Dorsiflex foot

Extensor Hallicus Longus

Origin: Fibula

Insertion: Distal phalanx - Digit 1

Action: Extends digit 1 - Inversion

Peroneus Tertius

Additional tendon of the extensor digitorum longus

Origin: Anterior shaft of fibula

Insertion: Base of 5th metatarsal

Action: Dorsiflexion & eversion of foot - tendon crosses anterior to lateral malleolus

Peroneus Longus

Origin: Upper 2/3 of lateral surface of fibula

Insertion: Medial cuneiform & base of first metatarsal

Tendon travels behind lateral malleolus, then under foot to medial side of foot

Action: Evert foot (strongest pronator)

Plantar flexion of the ankle

Peroneus Brevis

Lies deep to the peroneus longus

Origin: Lateral surface of fibula

Insertion: Lateral side of base of 5th metatarsal

Action: Eversion & plantar flexion

Tendon travels behind lateral malleolus ( alongside peroneus longus)

Plantar Flexors

Tendons that pass BEHIND lateral malleolus

Triceps Surae

Gastrocnemius (2 Heads) & Soleus

Gastrocnemius crosses both knee & ankle joints; Soleus crosses only ankle joint

Gastrocnemius

Most superficial posterior muscle

Origin: Lateral & medial epicondyles of femur - 2 heads of origin

Insertion: Posterior calcaneus (via Achilles Tendon) both heads combine into single tendon

Action: Plantar flexion & assists knee flexion

Soleus

Mostly lies deep to gastrocnemius

Origin: Posterior surface of tibia & fibula

Insertion: Posterior calcaneus via Achilles tendon

Tendon combines w/ gastrocnemius tendons to form Achilles tendon

Action: Plantarflexion

Tibialis Posterior

Origin: Posterior upper half of tibia & fibula

Insertion: Posterior surfaces of navicular, cuneiform, & bases of metatarsals 2-5

Action: Plantarflexion & inversion

Flexor Digitorum Longus

Origin: Posterior surface of tibia

Insertion: 2-5 Distal phalanges

Action: Flex digits 2-5 & plantar flexion

Helps support the arch