other

Question 1

typical joint elements – synovial joints

Answer 1

• proximal and distal bone
• articular/hyaline cartilage
• capsule
• ligaments
• synomivial membrane synovial fluid

Question 2

hilton’s law

Answer 2

• john hilton, british surgeon
• joint innervation
  
  • a nerve that innervates a joint also tends to innervate the muscles that move the joint and the skin that covers the distal attachments of the muscle
• example
  
  • elbow: radial, median, musculocutaneous, ulnar nn.
  • knee: femoral, sciatic (fibular and tibial), obturator nn.

Question 3

fibrocatilage in synovial joints

Answer 3

• meniscus, articular disc, laburm
• present in tibiofemoral, glenohumeral, acromioclavicular, sternoclavicular, termporomandibular, femoroacetabular
• purpose: to distibute compressive forces, provide additional joint stability/congruency

Question 4

types of synovial joints

Answer 4

• plane (gliding)
  
  • acromioclavicular
• hinge (ginglymus)
  
  • humeroulnar, tibiofemoral
• sellar (saddle)
  
  • sternoclavicular
• ellipsoidal (condyloid)
  
  • 2nd MCP
• ball and socket
  
  • glenohumeral
• trochoid (pivot)
  
  • proximal radioulnar (supination/pronation)

Question 5

planar joint

Answer 5

• lack of convexity/concavity along surfaces
• primary motion is gliding of two surfaces on one another
• examples
  
  • AC joint
  • SI joint
  • most spinal facet joints

Question 6

hinge joint

Answer 6

• ginglymus
• stable
• examples
  
  • humeroulnar
  • tibiofemoral

Question 7

sellar (saddle) joint

Answer 7

• examples
  
  • sternoclavicular joint
    
    • 1st carpometacarpal joint (thumb)

Question 8

ellipsoidal jiont

Answer 8

• CC and CV in all planes
  
  • ligaments provide stability
• example
  
  • metacarpal phalangeal joints

Question 9

pivot (trochoid) joint

Answer 9

• examples
  
  • atlantoaxial
  • proximal radioulnar

Question 10

convex on concave rule

Answer 10

roll and slide/glide opposite

Question 11

concave of convex rule

Answer 11

roll and slide/glide same diraction

Question 12

joints of the shoulder girdle

Answer 12

• sternoclavicular: only attachment of shoulder to body
• acromioclavicular: link to skeleton
• glenohumeral
• scapulothoracic: pseudojoint, only muscular attachments

Question 13

importance of scapular positioning

Answer 13

• glenoid moves like a seal’s nose to remain in right spot to control ball/head of humerus

Question 14

scapulohumeral rhythm

Answer 14

• consists of integrated movements of GH, ST, AC, and SC joints
• occurs in sequential fashion to allow full functional motion of shoulder complex
• serves three purposes
  
  • allows for greater overall shoulder ROM
  • maintains optimal contact between humeral head and glenoid fossa
  • assists with maintaining optimal length-tension relationship of glenohumeral muscles
    
    • for stability

Question 15

evidence summary on arm elevation

Answer 15

• scapular upward rotation may be greater on non-dominant side
• scapulohumeral rhythm between 1:3 and 1:5 depending on plane of humeral motion, side of dominance and age of patient
• unilateral or bilateral movement alters scapular and thoracic movement patterns

Question 16

role of thoracic spine

Answer 16

• bilateral shoulder motion: 10-30 degrees of thoracic extension (primarily lower) with full shoulder elevation
• unilateral shoulder motion: 10-30 degrees of thoracic rotation and/or side bending
• clinical relevance: assess thoracic motion in patients with shoulder symptoms

Question 17

restraints to external rotation at shoulder

Answer 17

• 0 degrees abduction
  
  • subscapularis
  • SGHL
• 45
  
  • SGHL
  • MGHL
• 90
  
  • anterior band IGHLC

Question 18

restraints to internal rotation

Answer 18

• 0
  
  • posterior band IGHLC
• 45
  
  • anterior and posterior band IGHLC
• 90
  
  • anterior and posterior band IGHLC

Question 19

restraints to inferior translation

Answer 19

• 0
  
  • SGHL
  • coracohumeral ligament
• 90
  
  • IGHLC

Question 20

GH joint accessory motion

Answer 20

• loose/open packed position
  
  • 55 deg abd, 30 deg horiz add
• closed packed position
  
  • end range abduction and ER

Question 21

CV-CC rule in shoulder

Answer 21

• ER always rolls posterior and glide anterior
• IR always roll anterior and glide posterior
• flexion always roll superior and glide inferior

NOT ALWAYS in GH joint

humeral head will glide away from the tightest portion of the capsule

Question 22

primary restraint against GH ER with arm at 45 degrees abduction

Answer 22

• middle glenohumeral ligament

Question 23

in protraction of shoulder girdle, what glide occurs at the sternoclavicular joint

Answer 23

• anterior

Question 24

distal attachment of subscapularis muscle

Answer 24

• lesser tubercle of humerus

Question 25

ligaments that restrict superior migration of the clavicle

Answer 25

• costoclavicular ligament
• conoid ligament
• acromioclavicular ligament

Question 26

primary stabilizer of GH joint at 90 degrees abduction

Answer 26

• inferior glenohumeral ligament complex

Question 27

carrying angle of elbow

Answer 27

• angle between axis of humerus and axis of forearm
• female: 12-16
• male: 10-14

Question 28

pronation and supination

Answer 28

• occurs simultaneously at both proximal and distal radioulnar joints
• also requires rotation of radius (spin) at humeroradial joint in anular ligament

Question 29

wrist axis of rotation

Answer 29

• flexion/extension: coronal axis between lunate and capitate
• rad/ulnar deviation: sagittal between unate and capitate
• circumduction: polyaxial
• center of rotation is variable dependent upon wrist position and motion

Question 30

radiocarpal kinematics

Answer 30

• gliding of proximal row on radius and TFCC
• gliding movement opposite from hand (convex on concave)

Question 31

midcarpal biomechanics

Answer 31

• joint: functional rather than anatomic convex on concave configuration (tongue and groove)
• motion: favors extension over flexion, opposite RC joint
  
  • small amount of RD/UD

Question 32

ligamentous stability “ring” system

Answer 32

• lichtman describes the carpus as “ring” system”
  
  • bones within each row tethered together by interosseous ligaments
  • ring is only complete by addition of midcarpal ligaments
  • carpal bones move together as a unit

Question 33

during wrist flexion, both rows flex and vice versa in extension

Answer 33

• 50% at MC and 50% at RC joints, but amount varies

Question 34

configuration of SI joints

Answer 34

• extremely variable from person to person in terms of morphology and mobility
• differences are not pathological, but are normal adaptations and anatomical variation

Question 35

primary function of SIJ

Answer 35

• distribute forces through pelvic ring

Question 36

stresses on knee ligaments

Answer 36

• valgus F stresses MCL
• varus stresses LCL
• anterior tensions ACL
• posterior tensions PCL

Question 37

menisci and weight bearing

Answer 37

• designed to distribute forces – hoop stress
  
  • WB restrictions after surgery

Question 38

meniscal blood supply

Answer 38

• blood flow is greatest in the peripheral 1/3 and is least in central 1/3
• healing capacity is vascularity and age dependent
  
  • also repeated injury

Question 39

medial meniscus repair considerations

Answer 39

• femoral condyle imparts sheer force to meniscus in weightbearing beyond 115-120 degrees of knee flexion
• hamstring contraction indirectly “tugs” on posterior horn of mensicus

Question 40

patellofemoral joint – compressive forces

Answer 40

• increase with degree of flexion angle at knee
• increase with quadriceps muscle force production
• surface area of contact increases with flexion
  
  • increased surface area results in reduced focal areas of pressure

Question 41

rearfoot-midfoot function

Answer 41

• supination
  
  • perpendicular axes –> rigid lever to push off
  • good for propelling forward (toe off)
• pronation
  
  • parallel axes –> “loose bag of bones”
  • attentuate forces for heel strike

Question 42

ground up or hip down for supination and pronation

Answer 42

• both