Lower Extremity

Question 1

Hip Joint: Function

Answer 1

supports load of head, arm, and trunk (HAT); the hip is the “true core”; force transmission, locomotion

Question 2

Pelvic Girdle: Structure

Answer 2

2 coxa or innominate bones; connected via symphysis pubis; pelvic girdle joints and symphysis joint;

Question 3

Sacroiliac Joints

Answer 3

2 paired gliding synovial joints found posteriorly; only move about 2-5 mm; if the SI joint is “out”, its only barely slid; lower lumber pain could refer down to the SI joints; have the fluid and capsules of a joint

Question 4

Innominate Bones

Answer 4

composed of 3 fused bones (fused, ilium, and ischium); contains the acetabulum, which is the articulating surface of the hip;

Question 5

Acetabulum

Answer 5

normally directed laterally, anteriorly, and slightly inferiorly; contains a wedge shaped labrum that deepens the socket and increases the concavity of the acetabulum

Question 6

Acetabular Anteverson

Answer 6

angle of anterior orientation of acetabulum is abnormal; normal range is 8 degrees for men and 14 degrees for women; increases in this angle associated with reduced joint stability and arthritis; decreased angulation associated with pathology;

Question 7

Transverse Acetabular Ligament

Answer 7

considered to be a part of the labrum; however contains no chondrocytes

Question 8

Acetabular Joint Capsule and Ligaments

Answer 8

joint capsule is strong and dense and contributes to joint stability; ligaments in the acetabulum reinforce the joint capsule (iliofemoral, pubofemoral, ischiofemoral, ligamentum teres)

Question 9

Trabecular System in the Femur

Answer 9

Present in the neck of the femur; resists bending stress by weight of HAT on femoral head;

Question 10

Zone of Weakness

Answer 10

area in the femoral neck where few trabecular fibers cross each other; likely to suffer fractures here when external demand is too great or when tissue can no longer resist stress/strain; decreasing crossing of trabecular fibers

Question 11

Hip: Osteokinematics

Answer 11

flexion, extension (commonly limited), abduction, adduction, internal rotation (commonly limited), external rotation

Question 12

Pelvis: Normal Position

Answer 12

12-15 degrees anterior pelvic tilt; if you have too much anterior tilt, you can encourage stretching the rectus femoris and strengthen the hamstrings and glutes

Question 13

Pelvis: Open Chain Movement

Answer 13

hip flexion= posterior pelvic tilt; hip extension = anterior pelvic tilt;

Question 14

Pelvis: Closed Chain Movement

Answer 14

hip flexion = anterior pelvic tilt; hip extension= posterior pelvic tilt; abduction/adduction = lateral pelvic tilt; right leg int/ left leg ext rotation = right pelvic rotation; left leg int/right leg ext rotation = left pelvic rotation

Question 15

Pelvic Motions

Answer 15

4 primary muscle groups influencing pelvic position; spinal extensors (anterior tilt), spinal flexors (posterior tilt), hip flexors (anterior tilt), hip extensors (posterior tilt)

Question 16

Hip Joint: Arthrokinematics

Answer 16

concave acetabulum and convex femoral head;

Question 17

Hip Joint: Acetabulum on Femoral Head

Answer 17

concave; posterior pelvic tilt (extension) = posterior roll and glide; anterior pelvic tilt (flexion) = anterior roll and glide;

Question 18

Hip Joint: Femoral head on Acetabulum

Answer 18

internal rotation = anterior roll and posterior glide; external rotation = posterior roll and anterior glide; abduction = superior roll and inferior glide; hip flexion = anterior roll and posterior glide

Question 19

Hip Joint: Closed Packed Position

Answer 19

extension, abduction, and internal rotation (back kick)

Question 20

Hip Joint: Open Packed Position

Answer 20

30 deg flexion, abduction, and 5 deg external rotation

Question 21

Hip Joint: Combined Motion

Answer 21

lumbar spine and pelvis; “lumbopelvic motion”; similar to scapulohumeral rhythm; lumbar spine flexes first then pelvis rotates to allow for more flexion; a limitation in flexibility can occur in either of these areas; hip motion alone only goes about 90 degrees

Question 22

Hip: Pathologies

Answer 22

Arthrosis, Fracture

Question 23

Hip: Arthrosis

Answer 23

degeneration of joint surface (articular cartilage); primary occurs in 10-15% of those over age 55%; secondary is due to previous trauma or malpositioning; risk factors included increased age, ante/retroversion; increased height/weight ratio; asymmetry; decreased bone density

Question 24

Hip Joint: Fracture

Answer 24

bending force across femoral neck –> increased force or weakening of bone= bony failure; average age of hip fracture 70; (cycle of fear of falling); trauma leads to sedentary leads to loss of balance and second trauma

Question 25

Knee: Function

Answer 25

alters length of the lower extremity; stability during weight bearing; mobility for ambulation; largest joint in the body

Question 26

Knee: Structure

Answer 26

ligaments (ACL, LCL, MCL, PCL) limit translation of the tibia; menisci (lateral and medial) reduces the incongruency of the joint (its a shallow joint);

Question 27

Knee: Medial Meniscus

Answer 27

3x as thick as the lateral meniscus; accepts more load; increases joint stability, shock absorption, reduces friction, distributes force; well vascularized early in life; without menisci contact area is reduced by 50% and the load on the femoral and tibial condyles increases;

Question 28

Knee: Anatomical Axis

Answer 28

longitudinal axis; relationship between femoral and tibial axes gives slight valgus angle (knees slightly bent in)

Question 29

Knee: Q Angle

Answer 29

angle formed between the lines from the tibial tuberosity up to the ASIS and from midpoint of patella up; larger in females (17) than males (14)

Question 30

Knee: Dynamic Q Angle

Answer 30

Q Angle when in motion; an indicator of potential injury including ACL tears and patellofemoral pain; single leg squats can help test

Question 31

Knee: Genu Valgum

Answer 31

increase in knee angulation of 10 degrees or more (knees in)

Question 32

Knee: Genu Varum

Answer 32

decrease in knee angulation of 10 degrees or more (knees out)

Question 33

Knee: Joint Capsule

Answer 33

attached to the rim of the patella; encloses the condyles; strengthened by ligaments, muscle, and tendons (IT band); 30 degrees of knee flexion is the loose packed position

Question 34

Knee: Ligament Stress Tests

Answer 34

``` MCL = stress test valgus by pushing ankle lateral LCL= stress test varus by pushing ankle medial PCL= stress test tibia backwards ACL= test tibia forwards ```

Question 35

Knee: Osteokinematics

Answer 35

Flexion (135-145 degrees), Extension (-5 degrees), Int/Ext Rotation (only occurs in flexion)

Question 36

Knee: Arthrokinematics

Answer 36

tibia is concave; femur is convex; tibia moves on femur when in open chain; femur moves on tibia when in closed chain

Question 37

Knee: Tibia on femur (open chain)

Answer 37

flexion: posterior roll and glide extension: anterior roll and glide

Question 38

Knee: Femur on tibia (closed chain)

Answer 38

flexion: posterior roll anterior glide extension: anterior roll, posterior glide

Question 39

Knee: Rotation

Answer 39

can only occur with unlocking of the knee; why? locking during extension is due to arthrokinematic movement (screw home mechanism)

Question 40

Knee: screw home mechanism

Answer 40

how the knee locks during extension; medial condyle is longer than the lateral condyle, so when you extend the knee, you run out of room on the medial side; the lateral condyle spins, thus the foot is externally rotated in full locked extension; medial gliding and rolling continues and spinning occurs at the lateral condyles

Question 41

Knee: Motion Limitations

Answer 41

extension is limited by scar tissue, joint capsule, ACL/PCL/MCL/LCL, hamstring, gastroc, joint capsule tightness; flexion limited by soft tissue, rec fem length, joint capsule tenderness

Question 42

Knee: Patellofemoral Joint

Answer 42

patella is like a sesamoid bone; increases mechanical advantage for quads; femoral surface of the patella with patellar surface of the femur;

Question 43

Knee: Patello Femoral Joint Functions

Answer 43

increases mechanical advantage of quads; disperses compressive forces of quads onto femur; protects anterior knee;

Question 44

Knee: Patellofemoral Motions

Answer 44

medial and lateral tilt; superior and inferior glide; medial and lateral glide;

Question 45

Knee: Patellofemoral Structure

Answer 45

Patellar stability Dependent on: bony (depth of groove), passive (ligaments), and active (muscles)

Question 46

Ankle: Function

Answer 46

provides a stable base while conforming to uneven surfaces; shock absorption through foot flexibility; transmits rotational forces into forward progression; rigid lever for propulsion

Question 47

Ankle: Anatomy

Answer 47

talocrural joint; ligaments (MCL, ACL, LCL); subtalar joint tibiotalar joint, calcaneocuboid joint; superior and inferior tib/fib joints

Question 48

Ankle: Talocrural joint

Answer 48

hinge joint (1 degree of freedom); proximal tibia/fibula (mortus) with the distal talus

Question 49

Ankle: Superior and Inferior Tib/Fib Joints

Answer 49

works together with the ankle; proximal tib/fib joint is a plane synovial joint with a capsule reinforced with ligaments; distal tib/fib joint is a syndesmosis (no joint capsule or much movement)

Question 50

Ankle: Osteokinematics

Answer 50

Dorsiflexion (0-20), plantar flexion (0-55);

Question 51

Ankle: Arthrokinematics

Answer 51

Talus is convex, tibia/fibula is concave;

Question 52

Ankle: talus moving on tibia/fibula (open chain)

Answer 52

dorsiflexion=anterior roll, posterior glide; plantar flexion= posterior roll, anterior glide

Question 53

Ankle: tibia/fibula moving on talus (closed chain)

Answer 53

dorsiflexion = anterior roll and glide; plantar flexion = posterior roll and glide

Question 54

Ankle: movement exceptions

Answer 54

plantar and dorsiflexion don't purely occur in the sagittal plane; has three components (eversion/inversion and a24/a44 are involved)

Question 55

Ankle: Dorsiflexion components

Answer 55

dorsiflexion, eversion, and abduction

Question 56

Ankle: Plantarflexion components

Answer 56

plantarflexion, inversion, adduction

Question 57

Ankle: Foot Anatomy

Answer 57

rearfoot = calcaneus, talus; midfoot= navicular, cuboid, cuneiforms; forefoot= metatarsals and phalanges

Question 58

Ankle: Subtalar Joint

Answer 58

talus on calcaneus; 3 separate articulations; single joint axis; contains the MCl, LCL and cervical ligaments

Question 59

Ankle: Subtalar Joint Function

Answer 59

dampens lower extremity rotations (when foot pronates, foot is adaptable and soft and can avoid shock); helps foot conform to uneven surfaces

Question 60

Ankle: Subtalar Joint Osteokinematics

Answer 60

pronation=loose pack position; allows foot to absorb shock during loading phase of gait; supination=closed pack position; creates rigid lever at beginning and end of gait

Question 61

Ankle: Transverse Tarsal Joints

Answer 61

motion in relation to subtalar motion; subtalar supination (axes of transverse tarsal joints cross to lock foot); subtalar pronation (axes align parallel to each other and foot unlocks); calcaneocuboid and talonavicular joints

Question 62

Ankle: Plantar Arches

Answer 62

longitudinal (calcaneus to metatarsal heads); transverse (across tarsals and proximal metatarsals); arches supported by ligaments and muscles; when you extend your toes, the fascia and spring ligament pulls the heel towards the toes

Question 63

Ankle: Plantar Fascia

Answer 63

pulls taut with 1st MTP extension; causes rearfoot supination or locking of the foot; windlass effect; arch raises or walks the foot when the toes are extended

Question 64

Ankle: Structural Pathologies

Answer 64

pes planus/cavus; rear foot varus and valgus; calcaneo-valgus and varus

Question 65

Ankle: Functional Pathologies

Answer 65

first ray hypomobility; hallux abductus valgus (bunions); ankle sprains cause ligament tears

Question 66

Ankle: Traumatic Pathologies

Answer 66

muscle strain, ligamentous strain, tendonopathy, plantar fasciitis