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
Which muscles upwardly rotate the scapula?
- Serratus anterior
- Upper traps
- Lower traps
Note: Middle traps are in line with the axis of rotation, but only stabilizes the scap rather than assisting with upward rotation
T or F? Active UE extension beyond neutral is combined with anterior tilting of the scapula
True
List all the muscles that internally rotate the shoulder
- Subscapularis
- Anterior deltoid
- Pec major
- Latissimus dorsi
- Teres major
(also has larger mass and torque than the external rotators)
List all the muscles that externally rotate the shoulder
- Infraspinatus
- Teres minor
- Posterior deltoid
(lowest torque of all motions)
Describe the arthrokinematics of 60 degrees scapular upward rotation
SC joint elevation, retraction, and posterior rotation
AC joint upward rotation
GH joint externally rotates
Which direction does the scapula tilt and rotate when abducting at the GH joint?
Posterior tilt, external rotation
T or F? Upward rotation preserves optimal length-tension relationship of abductors and flexors, while minimizing active insufficiency
True
T or F? When referring to the elbow, flexion torques are about 70% greater than extension torques
True
T or F? Flexion torques are maximal around 90 degrees of flexion, 25% greater in supination
True
Does the bicep contract quicker in a flexed or extended position?
Flexed
Describe the triceps
- All heads have capability to produce similar force
- Medial head activates for most extensor movements (“workhorse”)
- Lateral and long heads are recruited for high demands
- Long head is reserved for highest work performance
Describe the anconeus
- Initiate extension, generate low levels of force
- Acts more as a stabilizer
List the functions of the elbow extensors
- Provide static stability when weight bearing through the upper limb (prevents buckling)
- Generate large dynamic extensor torques when raising from a chair, pushing a door open, throwing a ball
- Maximum torque is at 90 degrees
- Largest moment arm at full extension
T or F? Supinators produce 25% greater torque than the pronators
True
T or F? The best way to test forearm pronation and supination is in an extended arm position
False, flexed elbow at 90 degrees is optimal
Describe the biceps brachii
- Recruited for high power activities
- 3x physiologic cross sectional area (allows for greater peak force)
- Maximal force is produced at 70 degrees of elbow flexion (elbow flexors in general produce greatest force at 90 degrees)
Describe the pronator teres
- Greatest activity during high powered pronation
Describe the pronator quadratus
- Most active and consistently used during all pronation regardless of power demands and elbow flexion angle
- Effective torque producer and stabilizer of DRUJ
During forearm pronation, the radius rolls __________ and slides _________ at the distal radioulnar joint
Anterior, Anterior
Maximal force generation of the supinators is at ______ degrees
90 degrees (because of biceps)
At the distal radioulnar joint, the radius is ______
Concave
Which carpal bones articulate with the distal radius?
Scaphoid and lunate
Describe the distal radius
Angled 25 degrees medially (ulnar tilt)
- Limits radial deviation
Angles 10 degrees in palmar direction (palmar tilt)
- Allows for greater flexion than extension
What is a tenodesis grip?
Wrist extended, fingers flexed
T or F? The carpal bones are all convex on concave from distal to proximal while the finger joints (DIP, PIP, etc.) are all concave on convex from distal to proximal
True
Differentiate between the proximal and distal row of the carpal bones
Proximal Row:
- Loosely joined to allow more movement
Distal Row:
- Bound tightly by strong ligaments
- Provides rigid base for articulation with metacarpals
Describe the radiocarpal joint (RCJ)
- Concave radius and articular disc
- Convex scaphoid, lunate, triquetrum
- 20% of compressive forces pass through the disc
- 80% of compressive forces pass through scaphoid/lunate to the radius
- Greatest contact area with slight extension and ulnar deviation
Describe the midcarpal joint (MCJ)
- Divides the two of carpal bones
- Convex on concave
- Medial midcarpal joint articulations have more movement than lateral
Describe the osteokinematics at the midcarpal joint (MCJ)
- Typically 10-15 degrees more flexion than extension (axis of rotation goes through the capitate)
- Ulnar deviation has 2x more ROM than radial
- 50-80% of maximum ROM is needed for normal function
T or F? Loading passes through the scaphoid and radius when transmitted proximal
True
Which nerve innervates the dorsal muscles (extensors)?
Radial n.
Which nerve innervates the palmar muscles (flexors)?
Median and Ulnar n.
Which muscle produces the greatest torque of primary wrist flexors?
Flexor Carpi Ulnaris (FCU)
T or F? Wrist flexors produce 70% greater torque than extensors due to cross sectional area
True
Which radial deviation muscles produce the most torque?
- Extensor carpi radialis longus
- Abductor pollicis longus
Which wrist radial deviator has the largest moment arm but smallest cross sectional area?
Extensor pollicis brevis
T or F? The radial deviators have 15% more torque than ulnar deviators
True
T or F? When referring to ulnar deviation, extensor carpi ulnaris and flexor carpi ulnaris produce the greatest torque
True
Describe the planes of movement of the 1st metacarpal
- Flexion/Extension: Occur in frontal plane
- Abduction and Adduction occur in sagittal plane
Which CMC joints are mobile, which are stable?
Mobile: Digits 1, 4, 5
Stable: Digits 2 and 3
Describe the 2nd/3rd carpometacarpal joints, and 4th/5th carpometacarpal joints
2nd/3rd:
- Minimal movement permitted due to interlocking articular surfaces and strong ligaments
- Firm attachment site of ECRL/B, FCR, Adductor Pollicis
4th/5th:
- Performs a cupping motion (1 degree of flexion with internal rotation)
- Arthrokinematics: roll and slide anterior during flexion
Which bone articulates with the 1st metacarpal to create the 1st CMC joint? Is the capsule loose or tight?
Trapezium
Loose capsule to allow for more movement
Describe the articulations at the metacarpophalangeal joints
- Convex head of metacarpal
- Concave base of proximal phalanges
T or F? The collateral ligaments of fingers limit abduction/adduction
True
Describe extrinsic finger flexors
- Consists of FDS, FDP and FPL (FDP is the only muscle that does DIP flexion)
- They can flex any joint they cross
- Extensors provide proximal stabilization
T or F? A posterior spin of the clavicle occurs during flexion and abduction
True
Describe the resting position of the scapula in the scapular plane
- 10-15 degrees anterior tilt
- 5-10 degrees upward rotation
- 35-45 degrees of internal rotation
Describe the arthrokinematics of abduction
- SC joint elevation
- SC joint posterior roll
- AC joint upward rotation
- GH external rotation
T or F? Upward rotation preserves length tension relationship of abductors (deltoids + supraspinatus), and prevents impingement (maximizes sub-acromial space)
True
T or F? The coracohumeral ligament is taut in adduction
True
T or F? The Superior GH Ligament limits inferior translation and ER at 0 degrees abduction
True
T or F? The middle GH ligament limits ER at 45-60 degrees of abduction
True
T or F? The inferior GH ligament limits ER at 90-120 degrees abduction
True
How do the teres minor, infraspinatus, and subscap provide dynamic stability at the GH joint?
- Inferior translation of humeral head
- Offsets the deltoids superior translation
How does the supraspinatus provide dynamic stability at the GH joint?
- Superior translation of the humeral head
- Offsets the stability of the infra, teres minor, and subscap
T or F? During abduction, the humerus also goes into external rotation so the greater tubercle can pass posterior to the acromion to avoid subacromial impingement
True
During GH abduction, the inferior capsule becomes ____, and _________________ of the humerus must occur in order to “clear” the greater tubercle
Taut, External Rotation
Describe the arthrokinematics of flexion at the GH joint
- Humeral head spins on glenoid
- 120 degrees of flexion (plus 60 from scap upward rotation)
Describe the muscles used and the arthrokinematics of scapular elevation
Muscles used
- Upper traps
- Levator scap
- Rhomboid minor/major
Arthrokinematics
- SCJ: Elevation
- ACJ: Downward rotation
Which muscles depress the scapula?
- Lower traps
- Latissimus dorsi
- Pec minor
- Subclavius
Which muscles retract the scap?
- Middle trap
- Rhomboids
- Lower traps
T or F? The deltoid needs upward rotation of the scap to maximize length tension relationship, as well as synergistic pull from ITS to stabilize the humeral head in order to effectively abduct the arm
True
What happens during deltoid paralysis?
The supraspinatus can fully abduct the shoulder, but strength is diminished due to deltoid weakness
What will happen to the scapula if a patient extends the arm past neutral?
Anterior tilt of the scapula
T or F? The pecs and lats generate the largest torque when adducting the shoulder
True
List the 6 parts of scapulohumeral rythym
1.) 120 degrees abduction to 60 degrees scap upward rotation (2:1)
2.) Upward rotation is a result of SC joint elevation and upward rotation of the AC joint
3.) SC joint retraction
4.) Scapula posterior tilts and externally rotates
5.) SC joint posterior rotation
6.) GH joint externally rotates
What happens if a patient has supraspinatus paralysis?
The deltoid will be unable to fully abduct
T or F? Length-tension relationship is at its peak when the sarcomeres are 2 micrometers long
True
Describe the IO membrane when carrying a weighted object
- Interosseus membrane slackens
- Increases the demands of the brachioradialis
- Fiber direction does not assist in dissipating distracting forces
If the shoulder is flexed to 30 degrees, how much elbow flexion should occur if you are trying to maximize length tension relationship?
60 degrees
(90 degrees of elbow flexion at neutral shoulder position)
List the 4 factors that play a role in force generation
- Cross sectional area
- Line of pull
- Moment arm
- Length tension relationship
T or F? The coracohumeral ligament becomes taut in adduction
True
Which hand/wrist position is best for maximizing grip strength?
- 35 degrees of wrist extension
- 5 degrees of ulnar deviation
T or F? The palmar plate of the interphalangeal joints limit hyperextension
True
