Flashcards in Module 3 Quiz Deck (346):
What are the bones of the pelvis?
Sacrum, Coccyx, 2 Pelvic Bones
What are the three components of a pelvic bone that fused together?
Why is the bony pelvis called the pelvic girdle?
It encircles the body and provides a firm, stable base of attachment for the femurs.
What are the 2 types of pelvic motion?
Intrapelvic (SIJ or pubic symphysis)
Entire pelvis (relative to trunk or thigh)
What is the major ligament of the pubic symphysis?
Arcuate pubic ligament
What type of joint is the SI joint?
Why does the SI joint transition from a synovial joint to a fibrous joint as we age?
Weight-bearing forces from above, wedging the sacrum into pelvic bones, and forces transmitted up from the LEs
Aside from non axial gliding, what major motion can the SI joints do?
Nutation/counternutation (axial movements in the sagittal plane)
What is nutation and counternutation?
Nutation - sacral base move anterior and inferior (but pelvis posterior tilts)
Counternutation - sacral base move posterior and superior (but pelvis anterior tilts)
Major ligaments of the SIJ (4)
Sacroiliac ligaments (ant, post, interosseus)
What is the dividing point between the greater and lesser sciatic notch?
The sciatic nerve exits the pelvis through the...?
Greater sciatic foramen (created by greater sciatic notch and sacrotuberous ligament)
What is the weight transfer occurring at the SIJ?
Weight of axial body to pelvic bones of lower extremities
What is reverse action of the lumbosacral joint?
When the pelvis moves relative to the lumbar spine at the LS
Also when lower lumbar spine moves relative to upper spine
Plane movements of the spine
Anterior/posterior tilt in sagittal plane
Depress/elevate in frontal plane (one side up one side down)
Rotation in transverse plane
Depression of the pelvis on one side is also called...
(Ex: right side depressed = right lateral tilt)
What is reverse action at the hips?
When pelvis moves on fixed thighs
ROM of pelvis
Anterior Tilt: 30
Posterior Tilt: 15
R/L Depression: 30
R/L Rotation: 15
Posterior tilt of the pelvis at the lumbosacral joint is analogous to _____ of the trunk at lumbosacral joint
Muscles that perform flexion of the trunk also perform ________ of the pelvis at the lumbosacral joint
Examples of muscles that would perform anterior tilt of the pelvis (extension of the trunk)
Erector spine group
Examples of muscles that would perform posterior tilt of the pelvis (flexion of the trunk)
Elevation of the right pelvis (depression of the left pelvis) at the LS is analogous to _________ of the trunk at the LS
right lateral flexion
Right rotation of the pelvis at the LS is analogous to _______ of the trunk at the LS
Examples of muscles that would perform right rotation of the pelvis (left rotation of the trunk)
Left-sided ipsilateral rotators (left erector spinae, letter internal oblique) and right contralateral rotators (right transversospinalis group, right external oblique)
Anterior tilt of the pelvis at the hip joint is analogous to ______ of the thigh
Muscles that perform flexion of the thigh also perform ______ of the pelvis
Muscles that perform extension of the thigh also perform ______ of the pelvis
Muscles that perform depression of the right pelvis also perform _______ of the right thigh
Muscles that depress the pelvis on one side of the body also _______ on the opposite side of the body
elevate the pelvis
Hiking the left hip means what is happening at the right hip?
Muscles that perform right rotation of the pelvis also perform ______ of the right thigh and _______ of the left thigh
medial rotation; lateral rotation
Which side of the pelvis is closer to midline anteriorly when rotating to the right?
Lateral rotators of the thigh at the hip joint can also perform ______ of the pelvis
Sacral base angle is a measure of the degree of _____ tilt of the sacrum
Any change in the sacral base angle affects _______ of the spine
Relationship between the posture and movement of the pelvis and spine is referred to as
What is a normal sacral base angle
A sacral base angle greater than 30 degrees results in _____ spinal curvature
The desire of the body to bring the head to a level posture is known as
Why do we want the head level?
Inner ear function for proprioception
ROM of hip joint
Ligaments of the hip joint (7)
Fibrous joint capsule
Transverse acetabular ligament
What is the zone orbicularis?
Strong circular deep fibers of the hip joint capsule that surround the neck of the femur
The fibrous capsule of the hip joint is reinforced by which 3 capsular ligaments?
Location of the iliofemoral ligament?
Anterior inferior iliac spine --> intertrochanteric line
Function of the iliofemoral ligament?
Limits extension of the thigh at hip
Limits posterior tilt of pelvis at hip
What is the Y ligament?
The iliofemoral ligament (shaped like an upside down Y)
If someone stands with extension of the hip joint (extended thigh or posterior pelvic tilt), which ligament holds the body weight?
Y ligament (iliofemoral ligament) - super strong!
Location of the pubofemoral ligament?
Pubis --> femur
Function of the pubofemoral ligament?
Limits abduction of thigh
Limits extreme extension of thigh
Limits ipsilateral depression of pelvis
Location of the ischiofemoral ligament?
ischium --> femur
Function of the ischiofemoral ligament?
Limits medial rotation of thigh
Limits extension of thigh
Limits ipsilateral rotation of pelvis
What ligament runs from internal surface of acetabulum to head of the femur? Purpose?
Conduit for blood vessels and nerves to femoral head
Closed-packed position of hip joint?
Articular cartilage of the acetabulum is also called...
lunate cartilage (crescent-shaped)
What is the labrum made of?
Purpose of labrum?
Increase depth of socket --> increasing stability
At the inferior margin of the acetabulum, the two ends of the labrum are connected by the...
transverse acetabular ligament
What is the concern with abnormal femoral angles of inclination and torsion?
Bone alignment / muscle compensations
Decreased shock absorption
Increased degenerative changes
What is the femoral angle of inclination?
Head/neck relative to shaft in frontal plane
Normal femoral angle of inclination?
Femoral angle of inclination <125 degrees is called...
Femoral angle of inclination >125 degrees is called...
Which leads to a longer lower extremity? Coxa vara or valga?
What is the femoral torsion angle?
Head/neck relative to shaft in transverse plane (shaft twisted medially relative to head and neck)
Normal femoral torsion angle?
Head/neck 15 degrees away from the frontal plane (anteversion)
Femoral torsion angle less than 15 degrees is called...
retroversion (more medially rotated when foot straight)
Femoral torsion angle greater than 15 degrees is called...
excessive anteversion (more laterally rotated when foot straight)
Which results in toe-in posture: retroversion or excessive anteversion
excessive anteversion (need to compensate by medially rotating thigh to get proper alignment)
Why does toe-in or toe-out posture occur?
Compensation to optimally line up the articular surfaces of the femur and acetabulum
Why is flexion posterior from the knee but anterior from the elbow?
Upper limb buds laterally rotate (ventral surface anterior) and lower limb buds medially rotate (ventral surface posterior) during embryo development
Why are children prone to toe-in posture?
Femoral torsion angle starts at about 30-40 degrees and decreases to 15 at about age 6.
What is a coupled action?
Two different joint actions tend to be coupled together (if one occurs, the other also tends to occur)
What is the coupled action to when a person flexes the right thigh at the hip to kick a ball?
Pelvis is posteriorly tilted at left thigh to increase range of motion of the kick
Thigh extension of the right hip is coupled with...
left pelvic anterior tilt
Thigh abduction of the right hip is coupled with...
Left pelvic depression
Thigh adduction of the right hip is coupled with...
Left pelvic elevation
Thigh lateral rotation of the right hip is coupled with...
Left pelvic rotation
What are the articulations of the tibiofemoral joint?
Medial/lateral condyles of femur
Plateau of tibia
What are the articulations of the patellofemoral joint?
Posterior surface of patella
Intercondylar groove of femur
What is the synovial subtype of the knee joint?
Modified hinge joint
How much knee flexion is required to allow rotation?
Medial rotation of the leg at the tibiofemoral joint is equivalent to ______ of the thigh at the tibiofemoral joint.
ROM of leg at tibiofemoral joint
Why are ligaments of tibiofemoral joint often injured?
Large forces transmitted to joint, weight-bearing, lack of bony stability - requires ligaments to work very hard at stability
Is the proximal tibiofibular joint in the knee joint capsule?
What is the anterior capsule of the tibiofemoral joint reinforced by?
Distal quadriceps femoris tendon
Retinacular fibers (expansions of quads)
What is the lateral capsule of the tibiofemoral joint reinforced by?
Lateral collateral ligament
Lateral retinacular fibers
What is the medial capsule of the tibiofemoral joint reinforced by?
Medial collateral ligament
3 pes anserine muscle tendons
Medial retinacular fibers
What is the posterior capsule of the tibiofemoral joint reinforced by?
Oblique popliteal ligament
Arcuate popliteal ligament
Fibrous expansions of popliteus, gastrocnemius, and hamstrings
What does the medial collateral ligament limit?
Abduction of the leg at the tib-fem joint in frontal plane
What are the attachments of the MCL?
Medial epicondyle of femur
Medial proximal tibia
What are the attachments of the LCL?
Lateral epicondyle of femur
Head of fibula
What does the LCL limit?
Adduction of leg at tib-fem joint in frontal plane
Are the cruciate ligaments of the knee intra-articular? Intra-synovial?
What are the attachments of the ACL?
What does the ACL limit?
Anterior translation of leg when thigh is fixed
Posterior translation of thigh when leg is fixed
Hyperextension of tibiofemoral joint
What are the attachments of the PCL?
What does the PCL limit?
Posterior translation of leg when thigh is fixed (anterior translation when leg is fixed)
End range flexion of tib-fem
If an impact from the lateral side causes abduction of the leg (genu valgum), what ligament will be torn?
Why is the LCL less injured than the MCL?
Would need a force from the medial side causing adduction of leg (genu varum) and this is less common
What is the test of translation of the knee joint?
Anterior/posterior drawer test
What is the most commonly injured ligament of the knee? How?
Anterior translation force of tibia on fixed thigh (posterior translation force of tibia on fixed leg); Hyperextension; rotation forces; "cutting" - forceful extension and rotation with planted foot
What does the oblique popliteal ligament limit?
Full extension of tib-fem
What does the arcuate popliteal ligament limit?
Full extension of tib-fem
Where is the patellar ligament?
Between patella and tibial tuberosity (part of distal tendon of quad fem)
What is the closed-packed position of the tib-fem joint?
What are the 3 pes anserine muscles?
How do the pes anserine muscles stabilize the knee joint?
Stabilize medial side
What are the menisci made of?
What are the open ends of the menisci called?
Where are menisci thickest/thinnest?
What is the function of the menisci?
Increase congruency of tib-fem joint and therefore stability (make sockets for the femoral condyles)
How much weight-bearing force do the menisci absorb
Half force through tib-fem joint
Why is the medial meniscus more frequently injured than lateral?
More firmly attached and therefore has decreased mobility
Also attached to the MCL and forces that stress the MCL also transfer to the medial meniscus
Why is healing difficult for menisci?
Blood supply is limited
What is the screw-home mechanism of the knee?
During last 30 degrees of tib-fem joint extension, concomitant rotation occurs
Lateral rotation of leg if thigh is fixed, medial rotation of thigh if leg is fixed
Locks joint and increases stability; decreases work of quads when in full extension
How much quad contraction is needed to maintain standing when knee joints are fully extended?
None (due to screw-home mechanism)
Mechanics of the screw-home mechanism?
Passive pull of ACL
Pull of vastus laterals
Larger lateral condyle keeps extending when medial condyle stops; lateral pivots around fixed medial condyle (medial rotation)
What is the most important muscle for unlocking the knee from full extension?
If thigh is fixed (open chain), popliteus _____ rotates the leg to unlock the knee
If leg is fixed (closed chain), popliteus _____ rotates the thigh to unlock the knee
Purpose of the patella?
Act as anatomic pulley - increasing leverage and force that quads exert on tibia
Reduces friction between quads tendon and femoral condyles
How much quad strength is lost if there is no patella?
Why does the articular surface of the patella have the thickest cartilage of any joint?
Quad contraction force creates compression of patella against femur
What causes patellofemoral syndrome (chondromalacia patella)?
Compressive forces of the patella on the femur plus improper tracking causes cartilage to damage and break down
When the knee is in full extension, the patella sits where?
Proximal to the intercondylar groove (freely moveable)
When the knee is flexed, the patella sits where?
Within the intercondylar groove (not much mobility)
When is patella most stable?
When knee is flexed (despite full extension being the closed-pack position of the knee)
What is genu valgum?
Abduction of tibia relative to femur
What is genu varum?
Adduction of tibia relative to femur
What is the normal value for genu valgum angle?
5-10 degrees (normal since femur is not vertical)
What is the value of excessive genu valgum (knock-knees)?
Greater than 10 degrees
What are factors contributing to increased genu valgum?
Overpronation of foot (lost arch)
Excessive femoral medial rotation/adduction
What is genu varum called?
Where are the tensile/compression forces of excessive genu valgum?
Where are the tensile/compression forces of excessive genu varum?
What is the Q-angle?
Intersection of 2 lines:
1. From tibial tuberosity to center of patella
2. Center of patella to ASIS
Angle (lateral) of pull of quads on patella
What is the implication of an increased Q-angle?
Pulls patella laterally and causes it to ride against lateral side of intercondylar groove - patellofemoral syndrome
What is the normal Q-angle measurement?
Why do women have a greater Q-angle?
Pelvis is wider
Does increased genu valgum or varum increase the Q-angle?
If a client has an increased Q-angle, what exercises are recommended?
Those aimed at strengthening the vastus medialis (counteract lateral pull)
What is genu recurvatum?
When knee joint hyperextends beyond 10 degrees
How does genu recurvatum occur?
Shape of tibial plateau slopes slightly posteriorly
Center of person's weight falls anterior to knee joint when standing
What type of joint is proximal tibiofibular?
Functionally, the proximal tib-fib joint is related to what other joint?
Ankle (not knee)
What type of joint is the middle tib-fib joint?
Purposes of the middle tib-fib joint?
Interosseous membrane holdes bones together so they can hold talus between them at ankle (talocrural joint)
Allows force of all muscle attachments that pull of fibula to be transferred to the tibia to move the leg at the knee joint
What type of joint is the distal tib-fib?
Why is stability of distal tib-fib most important for ankle function?
securely holds talus between the two bones
What direction is tibial torsion? Implication of movement at ankle joint?
Distal tibia faces somewhat laterally - dorsiflexion/plantarflexion occur in an oblique plane
The 2 bones of the leg articulate with the foot at what joint?
What is the hind foot?
Talus and calcaneus
What is the mid foot?
Navicular, cuboid, 3 cuneiforms
What is the forefoot?
Metatarsals and phalanges
What is the first ray?
first metatarsal and 2 phalanges of the big toe
Functions of the foot
Stable to support weight-bearing
Absorb shock from landing
Propel through space
Is the foot stable or flexible?
Rigid enough to absorb force (dorsi/plantarflexion) and flexible enough to navigate uneven surfaces (pro/supination)
Where is the subtalar joint?
Between talus and calcaneus
Where is the transverse tarsal joint?
Between talus/calcaneus and navicular/cuboid
What are the 3 arches of the foot?
What is the medial longitudinal arch?
Largest; length of foot on medial side
What is the lateral longitudinal arch?
Runs length of foot on lateral side (not as high as medial)
How do you evaluate the arches?
Observing in weight-bearing position
Anterior - height of arch
Posterior - bowing of Achilles tendon
What is pes cavus? Planus?
Cavus: excessive arch
Planus: decreased arch (flatfoot)
Implications of dropped arch?
Difference in leg height --> pelvis depressed or tilted to one side --> spinal curve
Structural stress on plantar fascia, knee joint, hip joint
What is the plantar fascia?
Dense fibrous tissue on plantar foot
What can cause a heel spur?
Plantar fasciitis due to tension placed on calcaneal attachment
Plantar fasciitis is caused most often by...
overly pronated foot
Purpose of the plantar fascia?
Maintain and stabilize longitudinal arches
Implication of walking in shoes?
Requires less work by intrinsic muscles leading to weakness of the muscles and plantar fascia --> loss of arch
What is the windlass mechanism?
During toe-off, metatarsals extend at MTP joints, which pulls plantar fascia taut (connected to MTP flexors) and makes foot more rigid to push the body forward
What is a retinaculum?
Acts to hold down tendons (important in wrist and ankle)
Why is retinaculum important in the ankle?
When leg muscles contract to move the foot or toes, retinaculum holds the tendons down, preventing them from bowstringing away from the body (which would weaken the muscle)
What is a mortise joint?
1 piece of wood with a notch and other piece carved to fit in the notch
Talocrural joint is similar to this (most congruent in body)
What kind of joint is the talocrural?
Synovial hinge (uniaxial diarthrotic)
What is the shape of the dome of the talus and how is this important?
Anterior aspect is wider than posterior
When foot dorsiflexes, wider aspect moves between tib-fib and pushes them apart - good for force absorption and stability
If the foot is fixed, the leg moves at what joint?
ROM of talocrural
What is the medial collateral ligament of the ankle also called?
Attachments of the deltoid ligament (MCL)?
Calcaneus, talus, navicular
The deltoid (MCL) limits...
eversion of the foot at the talocrural joint
pronation of foot at subtalar joint
Why are eversion sprains relatively uncommon?
Lateral malleolus extends down farther distally than medial malleolus (limits motion)
Deltoid (MCL) is very taut and strong
What are the 3 ligaments of the lateral collateral ligament of the ankle?
(all attach to distal fibula)
The LCL of the ankle limits...
inversion of the foot at the talocrural joint
supination of foot at subtalar joint
What is the most commonly sprained ligament in the body? Why?
Anterior talofibular (1/3 of LCL)
Usually occur when person is moving forward (plantar flexion + inversion) - places particular stress on ligament
Closed packed position of the talocrural joint
What protects tendons of the ankle from friction
What supports the talus on the medial side of the foot?
Sustentaculum tali (of calcaneus)
What is the sinus tarsus?
Large cavity on lateral side between talus and calcaneus
Type of joint: subtalar?
Uniaxial (triplanar), diarthrotic
ROM of subtalar (non-weight-bearing)
Major motions of the subtalar joint?
Pronation and supination in an oblique plane around an oblique axis
Pronation of foot =
Eversion, dorsiflexion, lateral rotation
Supination of foot =
Inversion, plantarflexion, medial rotation
What happens when the weight-bearing foot pronates and the talus medially rotates relative to the fixed calcaneus? Implication of overpronation?
Talocrural joint does not rotate, so leg must medially rotate with the talus
Overpronation subjects knee to medial rotation stress; knee doesn't allow rotation in extension so this medial rotation force is then transmitted to the hip joint
If a client has excessive pronation, the patella rotates in what direction?
Solutions to overpronated foot?
Strengthen supination muscles
Strengthen lateral rotation muscles of hip
What does the interosseous talocalcaneal ligament (in the sinus tarsus) limit?
Eversion (pronation) of subtalar joint
What does the cervical ligament (in the sinus tarsus) limit?
Inversion (supination) of the subtalar joint
Where is the spring ligament?
Spans subtalar joint on plantar side (calcaneus to navicular)
Spring ligament limits
Eversion (pronation) of subtalar joint
Closed packed position of subtalar joint?
Subtalar motion is intimately tied to which joints?
Transverse tarsal joint and talocrural joint
What are the 2 joints of the transverse tarsal joint?
Transverse tarsal joint is also known as
What are the motions of the transverse tarsal joint?
Pronation/supination (move with the subtalar joint)
The talus shares a joint capsule with which bones?
Calcaneus and navicular
Spring ligament forms the floor of which joint
Where is the long plantar ligament?
Length of foot on plantar side
Where is the short plantar ligament?
Deep to long plantar ligament on plantar side between calcaneus and cuboid
What is the bifurcate ligament?
Y-shaped ligament on dorsal side of foot (medial: calcaneus to navicular; lateral: calcaneus to cuboid)
Closed packed position of the transverse tarsal joint?
Type of joints: tarsometatarsals?
What is the central stable pillar of the foot?
2nd ray of foot (2nd TMT joint) - base is wedged between 1st and 3rd cuneiform joints
Reference line for abduction/adduction of toes
Major motions of TMT joints
Conform to surfaces
Proximal intermetatarsal joints are stabilized by
Joint capsules and inter metatarsal ligaments
Distal intermetatarsal joints are stabilized by
Joint capsules and deep transverse metatarsal ligaments
Why is the big toe unable to oppose?
Deep transverse metatarsal ligaments connect all of the distal metatarsals together, including the big toe (does not happen in hand)
Type of joint: metatarsophalangeal?
Major motion of the MTP joint
Abduction/adduction (transverse plane)
ROM of toes at MTP joints
Capsule of MTP joint stabilized by
collateral ligaments and plantar plate
What is the plantar plate?
Thick, dense, fibrous tissue structure on plantar side of MTP joint
Function of plantar plate
Protect head of MT when walking
Closed-packed position of MTP
What is hallux valgus?
Deformity of big toe in which big toe deviates laterally at MTP joint
Also medial deviation of 1st MT
How does hallux valgus occur?
Genetic predisposition or
Overpronation and incorrect footwear that pushes big toe laterally (heels, triangle front)
Implications of hallux valgus?
Exposes head of 1st MT to greater stress --> inflammation of bursa --> fibrosis and excessive bone growth on medial/dorsal MT (bunion)
Type of joint: interphalangeal joints
ROM of PIP joints
F: 90 (less laterally)
ROM of DIP joints
F: 45 (less laterally)
E: small hypertext
Interphalangeal joints are stabilized by
Closed packed position of IP joints of foot
What is the shoulder girdle made up of?
Scapula, clavicle, sternum
Function of the shoulder girdle?
Stable base for upper extremity to move
What ties the shoulder girdle together in the back?
Rhomboids and middle trapezius attach medial borders of the scapulae (like the lacing of a corset)
The net result of the sternoclavicular and acromioclavicular joints is to...
orient the scapula to the desired position
Position of the scapula is important to facilitate _____ motion at the _____ joint
The coupling of shoulder girdle movement with arm movement is called
scapulohumeral rhythm (or scapuloclaviculohumeral rhythm)
ROM of entire shoulder joint complex
Why is abduction of the glenohumeral joint restricted when arm is in neutral or IR?
Greater tubercle of head of humerus will connect with acromion process
ROM of GHJ (anatomic position)
Major reverse actions of the scapula at the GHJ?
Upward/downward rotation (when arm is fixed)
The capsule of the GHJ is so lax that if the muscles are completely relaxed, the head of the humerus can be moved how far from the glenoid fossa?
What are the 3 glenohumeral ligaments?
Function of GH ligaments
Prevent dislocation of humeral head anteriorly and inferiorly
Where do the majority of shoulder dislocations occur?
Foramen of Weitbrecht - small region of anterior GH capsule between superior and middle GH ligaments
Where is the coracohumeral ligament?
Between coracoid process (scapula) and greater tubercle (humerus)
Function of coracohumeral ligament
Prevents dislocation of humeral head anteriorly and inferiorly
Limits extremes of flexion, extension, and lateral rotation
Closed-packed position of GHJ
Lateral rotation and abduction
Abductor muscles of GHJ
Adductor muscles of GHJ
Lateral rotators of the GHJ?
Medial rotators of the GHJ
Flexors of GHJ
Extensors of GHJ
Long head of triceps brachii
Where is the subacromial bursa
Between acromion process and rotator cuff tendon
Irritation and injury of the rotator cuff tendon will also cause the same in the...
What is the coracoacromial arch? Function?
Formed by acromion process and coracoacromial ligament
Roof of GHJ; protects superior structures of GHJ
Why is the coracoacromial ligament unique?
Connects the same bone (coracoid profess and acromion process)
What are the superior structures of the GHJ that can become impinged between the head of the humerus and the coracoacromial arch during abduction/flexion?
Long head of biceps
Superior joint capsule
Where does the long head of the biceps go within the GHJ capsule?
Bicipital groove of humerus to supraglenoid tubercle of scapula
Why is the GHJ so mobile and less stable?
Shallow glenoid fossa and joint capsule laxity
Where is the majority of the shoulder stability coming from?
What ribs articulate in the scapula costal joint?
What kind of joint is scapulocostal?
Major motions of scapulocostal joint
What joints also need to move for motion of scapula at scapulocostal joint?
AC and SC
Scapular upward rotation accompanies what motion?
Accessory movements of the scapula?
What is a healthy tilt of the scapula?
Medially and downwardly
What is lateral tilt of the scapula called?
Winging of the scapula
Push-ups are an example of what action at the scapula?
Reverse action of scapulocostal joint. Trunk moves relative to scapula
Elevators of the scapula
Depressors of scapula
Pectoral is minor
Protractors of scapula
Retractors of the scapula
Upward rotators of the scapula
Downward rotators of scapula
Pectoral is minor
Type of joint: sternoclavicular
Major motions of the SCJ
Protraction/retraction (transverse plane)
Upward/downward rotation (sagittal)
ROM of clavicle at SCJ
Upward rotation: 45
Downward rotation: 0
Why does the SCJ need to be well stabilized?
Only osseous joint that connects the upper extremity to the axial skeleton
Motion of the scapula at the scapulocostal joint is driven by motion of...
the clavicle at the SCJ
What muscles stabilize the SCJ?
Which ligaments reinforce the SC joint capsule?
sternoclavicular ligaments (anterior and posterior)
What is the interclavicular ligament?
Spans from one clavicle to the other
What is the costoclavicular ligament?
Runs from first rib to clavicle
What is the closed-packed position of the SCJ?
Full upward rotation of the clavicle
Why is there an articular disc in the SCJ?
Improve congruence of joint surfaces and absorb shock
Type of joint: ACJ
Motions of the ACJ?
Upward/downward rotation of scapula relative to the clavicle
Accessory actions of the ACJ
Lateral/medial tilt of scapula
Upward/downward tilt of scapula
Accessory tilt actions of the scapula at the acromioclavicular joint are necessary to maintain...
proper position of the scapula relative to the ribcage
Upward rotation of the scapula follows what part of the bone?
Inferior angle (moving laterally)
ROM of scapula at ACJ
Upward rotation: 30
Downward rotation: 0
Muscle stabilization of the ACJ
Ligament reinforcement of the ACJ capsule
Acromioclavicular ligament (superior and inferior)
What are the 2 parts of the coracoclavicular ligament?
Closed packed position of the ACJ
Full upward rotation of the scapula
Is there a fibrocartilaginous disc in both the SCJ and ACJ?
The ACJ is very susceptible to...
injury and degeneration
What is typical injury to ACJ?
Falling on outstretched arm
In full 180 degrees of abduction, how much is from GHJ?
Flexion of the arm at the GHJ couples with.... of the scapula at the ScC joint
protraction and upward rotation
Extension of the arm at the GHJ couples with.... of the scapula at the ScC joint
retraction and downward rotation
Extension of the arm at the GHJ beyond neutral couples with ______ of the scapula at the ScC joint
Abduction of the arm at the GHJ couples with _____ of the scapula at the ScC joint
Adduction of the arm at the GHJ couples with _____ of the scapula at the ScC joint
Medial rotation of the arm at the GHJ couples with _____ of the scapula at the ScC joint
Lateral rotation of the arm at the GHJ couples with _____ of the scapula at the ScC joint
When the arm abducts at the GHJ more than approximately 90 degrees, it also need to _____ at the GHJ
Which muscles keep the head of the humerus down during arm elevation movements so there is no impingement?
Rotator cuff isometrically contracts to keep proximal humerus fixed in place while distal end elevates
What happens at early phase of arm abduction (first 90 degrees)
GHJ: 60 degrees
ScC upward rotation: 30 degrees
Clavicle elevates at SCJ (25 deg) and scapula upwardly rotates at ACJ (5 deg)
What happens at the late phase of arm abduction (last 90 degrees)
GHJ: 60 degrees
ScC upward rotation: 30 degrees
Clavicle elevates at SCJ (5 deg) and scapula upwardly rotates at ACJ (25 deg)
Implications of rounded shoulder posture on shoulder health?
Rounded posture = protracted scapula and medially rotated humerus
Abduction above 90 degrees will damage the rotator cuff and subacromial bursa due to greater tubercle impinging on acromion process
What are the 3 articulations in the elbow joint capsule?
Proximal radioulnar joint
Type of joint: humeroulnar
What part of the ulna connects to the distal humerus?
Type of joint: humeroradial
Synovial atypical ball-and-socket
ROM of elbow
3 parts of the MCL of the elbow
Function of the MCL of the elbow
Stabilize medial side of joint
Prevent abduction of forearm at elbow
2 parts of the LCL of the elbow
Function of the LCL of the elbow
Stabilize lateral side of joint
Prevent adduction of forearm at elbow
Closed packed position of elbow
Flexors of the elbow
Extensors of the elbow
Extensor carpi ulnaris
What is tennis elbow?
Inflammation of the common extensor tendon
Related to hand and wrist use
What is golfer's elbow
Inflammation of the common flexor tendon
Related to hand and wrist use
What is the carrying angle of the elbow?
Ulna deviates laterally in the frontal plane (relative to humerus)
Also called cubitus valgus
What is normal carrying angle?
Men: 5-10 deg
Women: 10-15 deg
Advantage of carrying angle?
objects carried in hand are naturally away from the body
Where does pronation/supination occur in the elbow?
At radioulnar joints (proximal, middle, and distal)
Type of joint: proximal radioulnar
Type of joint: middle radioulnar
Type of joint: distal radioulnar
What are the movements of the proximal and distal radioulnar joints during pronation?
Proximal: head of radius medial rotates
Distal: radius swings around ulna
What is the annular ligament of proximal radioulnar joint?
Wraps around head of radius - stabilizes proximal RU joint and creates a cavity within which the head of the radius can rotate
Function of the interosseous membrane of the middle RU joint?
Stabilizes radius and ulna
Transfers compression forces from radius at wrist to ulna into the arm (and vice versa)
Ligaments of the distal RU joint (2)
Dorsal and palmar radioulnar ligament
What is the radioulnar disc?
Also known as triangular fibrocartilage
Blends into capsular/ligamentous structure of both distal RU joint and radio carpal joint and adds stability to both