HK 302 - lecture 4

pelvis and hip myology continued; some associated pathology and clinical presentation; knee/ankle/foot osteology/arthrology/myology

sartorious

origin: ASIS and superior half of the notch

insertion: proximal part of the medial surface of the tibia

action:

• flexes, laterally rotates, and abducts the hip

• assists with knee flexion and medial rotation

innervation: femoral nerve

tensor fascia latae (TFL)

origin: anterior part of the external lip of the iliac crest, outer surface of the ASIS

insertion: into the IT band

action: flexes, medially rotates, and abducts the hip

innervation: superior gluteal nerve

muscles of the thigh

hamstrings (hip extensors/knee flexors):

• semimembranosus

• semitendinosus

• biceps femoris

quadriceps femoris (knee extensors):

• rectus femoris

• vastus lateralis

• vastus intermedialis

• vastus medialis

semimembranosus

origin: ischial tuberosity

insertion: posteromedial aspect of the medial tibial condyle

action:

• flexes and medially rotates the knee

• extends and assists in medial rotation of the hip

innervation: sciatic nerve

semitendinosus

origin: ischial tuberosity

insertion: proximal part of the medial surface of the body of the tibia

action:

• flexes and medially rotates the knee

• extends and assists in medial rotation of the hip

innervation: sciatic nerve

biceps femoris

origin:

• long head: distal part of the sacrotuberous ligament and posterior part of the ischial tuberosity of the innominate (os coxae)

• short head: linea aspera, proximal 2/3 of the supracondylar line of the femur

insertion: lateral side of the head of the fibula

action:

• flex and laterally rotate the knee joint

• the long head will assist in hip extension and lateral rotation

innervation: sciatic nerve

quadriceps femoris

origin:

• rectus femoris: anterior inferior iliac spine

• vastus lateralis: proximal portion of the intertrochanteric line, anterior/posterior borders of the greater trochanter

• vastus intermedialis: anterior and lateral surfaces of the proximal 2/3 of the body of the femur

• vastus medialis: distal half of the intertrochanteric line

insertion: proximal border of the patella and through the patellar ligament to the tibial tuberosity

action: extension of the knee; rectus femoris assists with hip flexion

innervation: femoral nerve

iliotibial band (IT band)

• thick, fibrous band running from hip to knee

• superior fibers are blending from TFL and gluteus maximus muscles

• inferior fibers insert into tibia at Gerdy’s tubercle

• primary function is stability in frontal plane

IT band friction syndrome

• occurs as the IT band repetitively crosses over the lateral femoral epicondyle as the knee flexes and extends

• generally pain is 1-2 cm above the knee joint line and most painful in about 20-30 degrees of knee flexion

• typically caused by training errors while running, lack of flexibility, or abnormal foot mechanics

patella

• largest sesmoid bone in the body

• protects the anterior knee and helps increase the mechanical advantage of the quadriceps

• bipartite patella - often mistaken for a patella fracture

• bone highly subject to disuse atrophy

knee

• composed of femur, tibia, fibula, and patella

• comprised of tibiofemoral joint and patellofemoral joint

  • tibiofemoral: between the femur and tibia; modified hinge joint

  • patellofemoral: between the femur and patella; gliding joint

patella ligament

• extracapsular ligament

• aka patella tendon

• connects patella to tibial tuberosity

• often used as a graft source for surgery

• wide range of clinical pathology present ranging from overuse to traumatic injuries

medial collateral ligament

• extracapsular ligament

• connects medial femoral condyle to medial tibia; strong, thick ligament

lateral collateral ligament

• connects femur to fibula

• gives minimal support to the lateral knee

MCL injuries

valgus knee force:

• foot must be on ground

• typical that knee is “rolled on” or foot is planted and knee collapses inward

• generally non-surgical if injured in isolation

• may miss 1-2 weeks or up to 3 months

anterior cruciate ligament

• intracpasular ligament

• prevents anterior tibial movement

• common mechanism of injury is hyperextension of knee or rotation with valgus knee collapse (plant and twist)

posterior cruciate ligament

• intracapsular ligament

• bigger of two cruciates; will heal non-operatively (but with some laxity)

ACL injuries

• rare injury overall - 1-2% of athletes in a year tear this

• loud pop, immediate effusion, 80% unable to continue

• generally surgery required to reconstruct knee

• typical recovery is 6-12 months

medial patellofemoral ligament

• patellofemoral ligament

• runs from the medial femoral epicondyle to the medial patellar facet

• helps keep patella from dislocating laterally

medial and lateral retinaculum

• patellofemoral ligament

• connective tissue that seats the patella in the trochlear groove

• deep to the patellofemoral ligament

patella dislocation

• typically happens in younger patients

• most frequently happens laterally because of femur anatomy

• painful, immediate swelling, recurrent problems

meniscus

• fibro cartilagenous structure

• medial meniscus: “C” shaped, firmly adhered to tibial surface via coronary ligaments

• lateral meniscus: “O” shaped, very mobile

• outer 1/3 = red zone; nutrition from blood supply

• middle 1/3 = red-white zone

• inner 1/3 = white zone; nutrition from synovial fluid (no blood supply)