Exam 3: UE Kinesiology Flashcards
What are the 4 arthrokinematic movements?
Roll, Glide/Slide, Spin, Traction (compression/distraction)
(note: traction is strictly compression or the pulling of opposite directions at a joint)
Describe the arthrokinematics of concave vs convex movement
Concave moving on Convex: Roll and Slide go the same direction
Convex moving on Concave: Roll and Slide go opposite directions
The humerus has ______ degree angle of inclination, and _______ degrees of retroversion to align with the scapular plane
135, 30
What is the only joint to link the appendicular skeleton to the axial skeleton?
SC joint
List and describe the function of the ligaments that provide the SC joint with stability
Interclavicular ligament
- Limits clavicular depression
Costoclavicular ligament
- Limits elevation of lateral clavicle
Sternoclavicular ligament
- Limits anterior/posterior directed forces
What are the primary functions of the articular disc at the SC joint?
- Increases joint congruence
- Strengthens articulation
- Provides shock absorption
T or F? SC joint dislocation is most common anteriorly
True
Describe the osteokinematics of the SC joint
Protraction/retraction
- Plane: Horizontal
- Axis: superior/inferior
Elevation
- Plane: Frontal
- Axis: Anterior/Posterior
Rotation/Spin
- Plane: Sagittal
- Axis: Medial-Lateral
T or F? All glenohumeral movement involves motion at the SC joint
True
List and describe the function of the ligaments that provide the AC joint with stability
Coracoclavicular ligament (2 parts)
- Trapezoid ligament: Limits posterior directed forces
- Conoid ligament: Limits superior directed forces
Describe the AC joint osteokinematics
Has limited mobility
Moves with the scapula
Abduction, adduction, flexion, extension
- Plane: Frontal
- Axis: Anterior/Posterior
IR/ER
- Plane: Horizontal
- Axis: Vertical
Anterior/Posterior Tilt
- Plane: Sagittal
- Axis: Medial/Lateral
Which muscles stabilize the SC joint?
- SCM
- Sternohyoid
- Sternothyroid
- Subclavius
T or F? The sternal end of the clavicle is convex from superior to inferior, but concave from anterior to posterior
True
When performing shoulder abduction/adduction, the roll and glide are ___________. When performing shoulder protraction and retraction, the roll and glide are ___________
Opposite, Same
(this is due to the sternal end of clavicle being convex from superior/inferior, but concave from anterior/posterior)
What is the scapulothoracic (ST) joint? Describe the positioning and actions as well
The joint between the anterior scapula and the posterior/lateral thorax
At rest
- 10-15 degrees of anterior tilt
- 5-10 degrees of upward rotation
- 35-45 degrees of internal rotation
Actions
- Elevation/Depression
- Protraction/Retraction
- Upward/Downward rotation
(these all occur due to SC and AC joint motion)
(note: this technically isn’t a real joint)
T or F? During scapular protraction, the AC joint contributes by internally rotating
True
Summarize the SC joint, AC joint, and ST joint
SC joint:
- Moves in all 3 planes
- Has concave and convex surface
- Very stable joint
AC joint:
- Plane joint (no roll/spin)
- Upward/downward rotation
- Can be dislocated easily
ST joint:
- All motions occur as a result as SC or AC joint movement
Describe upward rotation
- Projects glenoid upward and anterior-lateral
- Preserves length-tension relationship of abductors (deltoid and supraspinatus)
- Maintain volume of subacromial space
- SC joint elevation, AC joint upward rotation
Describe the arthrokinematics of the SC and AC joint during elevation, upward rotation, and protraction
Elevation: SC joint elevation, slight AC joint depression (to keep scap vertical)
Upward Rotation: SC joint elevation, AC joint upward rotation
Protraction: SC joint protraction, AC joint internal rotation
T or F? There are no movements that come directly from the ST joint, the motions just follow the AC and SC joint
True
Describe the GH joint (type of capsule, muscles providing stability, ligaments providing stability)
Fibrous joint capsule
Active Stability of GH Joint:
- long head of biceps
- rotator cuff muscles/tendons
Dynamic Stability of GH Joint:
- Coracohumeral Ligament (CHL)
- Superior Glenohumeral Ligament (SGHL)
- Middle Glenohumeral Ligament (MGHL)
- Inferior Glenohumeral Ligament (IGHL)
Also receives stability from labrum (accounts for 50% of glenoid fossa depth)
What are the 4 functions of the glenoid labrum?
- Resist humeral head translations
- Increase contact area, decrease joint stress
- Increases joint stability
- Attachment site for biceps
Describe the GH joint osteokinematics
Abduction
- 120 degrees of abduction (plus 60 from scapula upward rotation
- Accompanied by external rotation
Describe the GH joint arthrokinematics
Abduction
- Inferior capsule becomes taut
- Supraspinatus contracts and makes superior capsule taut
- Simultaneous ER to “clear” greater tubercle to prevent it from getting caught
Flexion
- Spin at GH joint
- 120 degrees of flexion, accompanied by 60 degrees of scapular upward rotation
Extension
- Accompanied by anterior tilting of scapula
Describe the roll and slide during external rotation?
Roll: Posterior
Slide: Anterior
Where do the proximal stabilizers, and distal mobilizers originate and insert?
Proximal Stabilizers
- Origin: Spine, Ribs, Cranium
- Insertion: Scap or Clavicle
Distal Mobilizers
- Origin: Scap or Clavicle
- Insertion: Humerus
Which muscles elevate the scapulothoracic (ST) joint?
- Levator scap
- Rhomboid major
- Rhomboid minor
Which muscles depress the scapulothoracic (ST) joint?
- Lower traps
- Latissimus Dorsi
- Pec Minor
- Subclavius
Which muscle protracts the scapulothoracic (ST) joint? What are the arthrokinematics of the SC and AC joints?
Serratus anterior
SCJ: Protraction
ACJ: IR
Which muscles retract the scapulothoracic (ST) joint?
- Middle trapezius (primary mover)
- Rhomboids
- Lower trapezius
Which muscles abduct the GH joint? Which muscles flex the GH joint?⁉️⁉️⁉️⁉️
Abduction
- Middle delt
- Supraspinatus
- Anterior delt
- Coracobrachialis
Flexion
- Coracobrachialis
- Long head of biceps
- Rotator cuff muscles
T or F? The deltoids cause superior translation when contracted and need assistance from a synergistic force to elevate the arm
True
What are the primary functions of the supraspinatus?
- Abduct the humerus (first 30 degrees)
- Has a moment arm larger than deltoid for initial 60 degrees of abduction
- Compress the GH joint (Promotes stability)
T or F? The deltoid and supraspinatus are at their strongest at 45 degrees of abduction
False, 90 degrees
LEFT OFF ON SHOULDER 2 LECTURE “UPWARD ROTATORS”, SLIDE 33 (HAVE NOT MADE CARDS FOR REST OF SLIDES)
Which joints make up the “elbow”? What type of joint is it?
Humeroulnar and humeroradial joints
Hinge joint
T or F? The trochlea and trochlear notch provide the majority of the structural stability of the elbow
True
Describe the fiber orientation and function of the interosseus membrane
Fiber Orientation: proximal/lateral to distal/medial
Function:
- Connects radius to ulna
- Attachment site for extrinsic hand muscles
- Transmits force proximally from radius to ulna
T or F? When compressed distally, the force is dispersed between both the ulna and radius due to the orientation of the IO membrane. When pulled away from the elbow (carrying groceries, etc), most of the force is on the radius due to the orientation of the IO membrane
True
Describe the proximal radioulnar joint
- Shares joint capsule with humeroulnar joint
- Radial head (convex) is held against the radial notch of the ulna via the annular ligament
Describe the distal radioulnar joint
- Radius (concave) on ulna (convex)
- Gets stability from muscle contraction and connective tissue (not IO stability)
- Has an articular disc
Describe the TFCC
- Occupies the ulnocarpal space
- Primary stabilizer of the distal radioulnar joint
- TFCC tears can cause a dislocation of distal radioulnar joint
Describe the joint surfaces of the proximal radioulnar joint
Radial head (convex), moves within the radial notch (concave) of ulna
When pronating, there is an anterior roll, posterior slide
When supinating, there is a posterior roll, anterior slide
T or F? The palmar ligament stretches and stabilizes during supination
True
T or F? The dorsal capsular ligament becomes taut (tight) during pronation
True
Describe the arthrokinematics at the distal radioulnar joint
Radius rolls and slide anterior in relation to the ulna (stationary)
T or F? During pronation and supination, the radial head spins on the capitulum
True
What are the functions of the elbow flexors
Biceps (Strongest at 70 degrees of flexion)
- Maximal activation during both flexion and supination
- Low activation when flexion occurs in pronated position
Brachialis (Strongest at 90 degrees of flexion)
- Largest muscle that crosses elbow (HAS THE GREATEST FORCE)
- Contracted with both pronated or supinated grip
Brachioradialis (Strongest at 90 degrees of flexion)
- Longest muscle crossing the elbow
- Maximal activation during rapid movement under high resistance