Lecture 1 - 3 review

Question 1

what is the concave + convex rule?

Answer 1

-convex over a stationary concave surface, slide occurs in the opposite direction as the movement of the bony lever

-concave surface moves over a stationary convex surface, slide occurs in the same direction as the movement of the bony lever

Question 2

what is a closed-pack position?

Answer 2

-Joint surfaces are maximally congruent
-Surrounding ligaments and joint capsule are taut in this position
-This is the position for the greatest stability of the joint
-Each joint has its own closed packed position (CPP)

Question 3

what is an open-packed joint position?

Answer 3

-Joint surfaces are relatively free to move in relation to one another
-AROM and PROM as well as joint play occur here

Question 4

what is a capsular pattern?

Answer 4

The typical pattern of limitation in a joint’s movement if the capsule is the structure limiting its movement
examples-adhesive capsulitis, reactive arthritis
, neoplasm extending into the capsule
-each joint has its own capsular pattern.

Question 5

what is scaption?

Answer 5

-Scaption is shoulder elevation in the scapular plane
-That is the plane 30-40 degrees anterior to the true frontal plane
-There is less likelihood of impingement of subacromial structures in scaption combined with ext rot of GH than traditional abduction in the frontal plane combined with external rotation

Question 6

what is the ratio between movements at the GH and ST joints?

Answer 6

-2:1
-For every 1-degree scapular motion, the humerus moves 2 degrees
-Primarily describes abduction but also scaption and flexion

Question 7

how do arthro-kinematic movements change in a closed chain?

Answer 7

arthro-kinematics reversed

Question 8

what is the role of the scapula in the GH movement?

Answer 8

• scapular motion designed to create maximum congruency
• serratus plays an important role; lack of co-activation of other scapular mm increases the load on serratus anterior, increasing the likelihood of fatigue
  -If superior rotation is limited, more likely to develop impingement syndrome

Question 9

where do 0-30 degrees of scapular rhythm abduction occur?

Answer 9

-primarily in the GH joint
-very little scapular motion; scapular setting

Question 10

what occurs at 30-90 degrees?

Answer 10

-Axis of rotation at the base of the spine of the scapula
-superior rotation from the upper and lower trapezius and serratus anterior
-motion occurring at sc as coracoclavicular ligaments pulled taut restricting AC

Question 11

what occurs at 90-165 Degrees Abduction?

Answer 11

-The axis of rotation at the AC joint (roughly)
-glenoid fossa of the scapula continues to rotate superiorly now while the coracoid is drawn infero-medially
-pulls clavicle into the posterior rotation from coracoclavicular ligaments

Question 12

what occurs at 165-180 Degrees Abduction?

Answer 12

-If one arm is abducted or flexed, then there is contralateral lateral flexion
-If in flexion or abduction BL, then the thoracic spine moves into extension and the lumbar lordotic curve exaggerated to achieve full ROM

Question 13

what is reverse scapulohumeral rhythm?

Answer 13

-The scapula moves more than the humerus

• occurs with shoulder hiking in frozen shoulder

Question 14

what is a fused SC joint?

Answer 14

-no scapular motion occurs

-limited to GH motion alone (approx 60-80 deg)

-occurs with repeated dislocation or OA

Question 15

what occurs with no external humeral rotation?

Answer 15

Abduction limited to 120 degrees as greater tubercle abuts the acromion

Question 16

what occurs with no clavicular rotation?

Answer 16

-Occurs after A/C Joint fusion

-Thus limited to 120 degrees of abduction as SITS tendons unable to clear the subacromial arch

-May also lose some posterior rotation with total AC dislocation

Question 17

what is a force couple?

Answer 17

two forces whose points of application occur on opposite sides of an axis & in opposite directions to produce rotation

note: trapezius seems to be more important during GH abduction, and serratus anterior during flexion

Question 18

what range is the painful arc in the glenohumeral joint?

Answer 18

60-120 degrees of abduction

Question 19

what is the role of the subscapularis, teres minor, and infraspinatus muscle in the shoulder?

Answer 19

-synergist muscles of the shoulder
-create a resultant muscle force vector with a joint-stabilizing rotary component and an inferior translatory component
-translatory pull offsets the superior pull of the deltoid during the initial stages of abduction

Question 20

what occurs when there is absence or weakness in the subscapularis, teres minor, and infraspinatus muscles?

Answer 20

absence/weakness of these muscles would have the humeral head impinge on the coracoacromial arch

Question 21

what is the carrying angle of the elbow?

Answer 21

-Axis of rotation for flexion and extension passes through the trochlea and capitulum
-oriented inferomedial
-Carrying angle of the elbow is the angle between the long axes of the humerus and ulna
Men=5 degrees & Women=10-15 degrees

Question 22

what is the fixed (proximal) transverse arch?

Answer 22

-Formed by the distal row of carpals
-Concavity that persists even when the palm is flattened

Question 23

what is the Mobile (Distal) Transverse Arch?

Answer 23

-Formed by the mobile 1st, 4th & 5th CMC joints moving around stable 2nd & 3rd CMC joints

-Allows for maximum surface contact when grasping objects

Question 24

what is prehension?

Answer 24

activities of the hand involving grasping or taking hold of an object between any two surfaces in the hand; the thumb may or may not participate