Exam 3: UE Kinesiology Flashcards
(122 cards)
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