BiomechIV-test1 Flashcards
(163 cards)
1
Q
What is the biomechanical triad:
A
A) muscle, skeleton, joints
2
Q
Seven Parts of Typical Long Bones?
A
A) Diaphysis, Metaphysis (2), Epiphyseal Plates (2), Epiphysis (2)
3
Q
What parts are paired?
A
Metaphysis, epiphyseal plates, epiphysis
4
Q
What parts are cartilage?
A
Epiphyseal plates (place of cell proliferation)
5
Q
What part results in longitudinal growth and when does this occur?
A
A) Proliferation of chondrocytes at epiphyseal plates
B) occurs in children before physis is closed and cartilage is replaced with bone
6
Q
Other names for shaft and epiphyseal plate?
A
A) Shaft: diaphysis and body
B) Epiphyseal plate: plates (in children), physis or lines (in adults)
7
Q
What is the difference between epiphysis and apophysis?
A
A) Epiphysis: primary site of bone growth. Ex: physis
B) Apophysis: secondary site of bone growth. Accessory physis for tubercles, tuberosities and epicondyles.
8
Q
Where is subchondral bone located?
A
A) Located deep (immediately adjacent) to articular cartilage and is part of the metaphysis
9
Q
What type of bone is subchondral bone?
A
A) Is cancellous (spongy) bone
10
Q
Does subchondral bone absorb shock?
A
Yes, it is responsible for transferring loads to the diaphyseal cortex (diaphysis). It forms an intermediate zone between articular cartilage and the cortical bone providing protection to both.
11
Q
Is subchondral bone vascular?
A
yes
12
Q
How do nutrients get to deepest layers of cartilage that is next to subchondral bone?
A
Subchondral vessels supply the adjacent deep transition zone of articular cartilage while diffusion from
nearby vessels in the periosteum and synovial membrane contribute to the delivery of nutrients to the
peripheral transition zones between articular and intra-articular cartilage.
13
Q
What is the effects of degenerative arthrosis on subchondral bone?
A
A) Increased calcification leads to increased rigidity B) increased thickness leads to increased rigidity and impedes the flow of blood in the metaphysis leading to
further degeneration C) sclerosis on xrays- known as subchondral sclerosis or eburnation D) decreased shock absorption
14
Q
What is found in the joint/synovial cavity? And how much?
A
A) Synovial fluid rich in GAGs especially hyaluronic acid B) enough to form a film C) Synovial fluid is normally a transudate of blood coursing through capillaries of the synovial membrane
with addition of hyaluronic acid secreted by intimal cells of the synovial membrane
15
Q
What makes synovial cavity slippery?
A
A) Synovial fluid. It is very viscous and slippery
16
Q
What does GAG stand for?
A
glycosaminoglycans
17
Q
Hyaluronic acid is the most important component of synovial fluid other than water. List 4 functions of synovial fluid?
A
Shock absorption, lubrication, supply nutrition, waste product removals
18
Q
What produces synovial Fluid?
A
Synovial fluid is secreted by the intima of the synovial membrane
19
Q
Name the 2 layers of synovial membrane.
A
A) Intima (innermost layer)
B) Subintima= connective tissue (thicker outer layer)
20
Q
Which synovial layer is very thin, composed of secretory epithelioid cells and does not contain blood vessels
or nerves and is nearest the joint cavity?
A
intima
21
Q
Which layer is thicker, vascularized, innervated, and connected to fibrous capsule, and is composed of
adipose, fibrous or elastic connective tissue?
A
subintima
22
Q
What is the significance of fenestrated capillaries in subintima of synovial membrane?
A
Fenestrated capillaries allow increased fluid exchange, allowing nutrients in and waste out.
23
Q
What type of fibrous CT predominates in fibrous capsule?
A
Dense irregular connective tissue
24
Q
What are dissectible thickenings of fibrous capsule?
A
A) Not exactly sure of answer.
B) Extra Capsular or Capsular ligaments that function to reinforce sites of mechanical stress
25
What is an extracapsular ligament?
A) Ligament found outside the joint that is far more important for static support than intra-capsular ligaments
26
What fibers attach the capsule, ligaments, and tendons to bone?
A) Sharpeys fibers
27
What are sharpeys fibers composed of?
A) Collagen fiber bundles that intermingle with the collagen fiber of bone
28
What is wolffs law?
A) Bone forms in response to stress forces on that bone/landmark B) Bone responds to external stress. With more tension on the bone the more bone will be laid done
29
What do fibroblasts do?
A) They form collagen fibers in connective tissue, which are oriented in response to the direction of stress
applied to the tissue B) no stress on collagen causes random orientation C) fibroblasts are responsible for scarring in the CT.
30
Is the capsule innervated and vascularized?
A) Yes (both capsulated and non capsulated)
31
What are the two types of tissue that are the most vascularized in the extremities?
A) Bone and muscle B) increased vascularization leads to increased bruising and bleeding with injury
32
Define bursa.
A) Synovial membrane lined extra-capsular pouch/pocket that can and cannot communicate with joint
cavities, allowing smoother joint movement.
33
. Give example of bursa that do and do not communicate with joint cavities.
A) Communicating: suprapatellar and popliteus bursae
| B) noncommunicating: pre-patellar and pes anserine bursae
34
What effects does internal derangement/ injury of a joint have?
A) May lead to swelling of bursae that connect to the joint
35
What is the function of bursae?
A) They reduce friction between layers of tissue
36
What is the function of synovial sheaths that surround tendons?
A) They enhance gliding through restricted spaces. Ex: carpal tunnel
37
What cell type predominates in articular and intra articular cartilage?
A) Water is a main component of both, followed by collagen then GAGs.
38
What are the major functions of GAGs and collagen?
A) GAGs are hydrophilic (sponge like) and resist compressive forces whereas collagen resists expansion of cartilage, traction and shearing forces.
39
What direction is collagen oriented at the surface and deeper inside joints? What is this significance of this?
```
A) Collagen is oriented perpendicular to the joint surface in deeper layers and parallel to joint surfaces at the
superficial layers (to resist shear forces that would otherwise rip off the surface tissue when joint surfaces rub on each other.)
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40
Are all articular surfaces lined by hyaline cartilage?
A) Most joints are lined by hyaline cartilage
41
Which 3.5 surfaces are not line by hyaline cartilage?
Acromioclavicular joint, Sternoclavicular joint, and Temperomandibular joint + 1⁄2 SI joint
42
Name the most important GAGs in cartilage.
Chondroitin sulfate and glucosamine sulfate.
43
Know that sulfated GAGs are important. Why?
A) They enhance cartilage proliferation and healing
44
What cartilage changes occur with degenerative arthrosis?
A) Uneven wear pattern of cartilage and thinning
45
How would you characterize the normal chondrocyte population?
A) Not sure but: a recycling population of cells that are responsible for maintenance and repair of cartilage matrix.
B) Chondrocytes are flattened along the joint surface organized in chains parallel to articular cartilage and are round in shape in deep parts of the cartilage oriented perpendicular to the articular surface.
C) In normal adult cartilage there is no further mitosis and growth subsides.
46
What changes in cartilage occur in the aging population?
A) Chondrocyte population decreases resulting less fluid exchange to the tissue. B) Thus the rate and quality of proteoglycan production is also reduced leaving potential for repair and
regeneration of articular cartilage to diminish.
47
What is boundary lubrication and how does it occur at joints surfaces?
A) Boundary lubrication is like teflon. It is when synovial fluid glycoproteins bind to cartilage surfaces to create a slippery surface.
48
Is it effective at high or low compressive/shear loads?
A) Boundary lubrication is only effective when exposed to small loads and fails as a lubricant under high
loads
49
What is hydrostatic lubrication and how does synovial fluid move in/out of cartilage?
A) Hydrostatic lubrication also referred to as fluid film lubrication occurs when the interstitial fluid is squeezed out of the articular cartilage under compression and forms a viscous slippery fluid interface that separates and protects adjacent cartilage surfaces from damage due to compressive and shear stress.
B) Is good under high compressive loads but requires that the cartilage deform like a sponge
50
Why is rapid pressure oscillations bad and slow pressure fluctuations good?
A) Rapid oscillations reduces the cartilage proteoglycan water holding capacity. With less fluid being squeezed out when under high loads, there is a resultant increase in friction and accelerated wear and tear of articular surfaces as well as sustained pressure on cartilage.
B) Tissue also becomes dampened due to progressive loss of fluid C) Rapid oscillations/ no oscillations are bad because they decrease fluid exchange and cause cartilage to be
starved of nutrients
51
Note that most slow pressure oscillations occur with normal joint movements.
A) Pressure oscillations found in normal ADLs.
| B) Slow pressure fluctuations are good because it allows fluid exchange.
52
What produces fast oscillations?
A) Vibratory tools, motor vehicles, repetitious activity
53
How does lubrication change with degenerative arthrosis? Explain.
A) Cell population declines (natural process that occurs while you age and as tissue is damaged) B) GAGs decrease, but serous fluid increases C) Lubrication declines D) Calcification occurs
54
Name 4 joints with intra articular cartilages. Which one of the four has hyaline articular cartilage?
A) AC (early 20s) SC, TMJ and ulnocarpal. Disc has hyaline intra articular cartilage
55
What are the other 3 joints lined by?
A) Fibrocartilage
56
List 5 functions of intra articular cartilage.
A) Increased shock absorption, increased congruency, increased stability, decreased friction, increased motion
57
Are intra articular cartilage innervated or vascularized? If so, what parts?
A) Yes.
B) The outer transition w/ capsule is innervated for proprioception and nociceptors C) the outer 1/3 of the cartilage is vascularized the inner 2/3 is not vascularized and receives fluid via
diffusion
58
How do the collage fibers and blood supply change with aging? What does this lead to?
A) As we age collagen fibers are laid down in a more haphazard fashion and blood supply to the tissue progressively decreases. This leads to degeneration of joints over time due to lack of nutrients and proper waste removal.
59
What is the role of muscles and their tendons in the support of joints?
A) They provide dynamic support for the joint
60
What is dynamic stability?
A) The ability for muscles and tendons to support a joint externally. B) Is active protection by joint motion and muscle contraction called negative work and is the most
important factor in sparing synovial joints from excessive loading.
61
What is proprioception?
A) Awareness of a joint/muscle/tissue in space.
62
How does lack of muscle support and balance lead to joint injury and degeneration?
A) Lack of muscle causes inappropriate or uneven where on articular cartilage causing rapid degeneration/ joint injury. It may also lead to bone on bone joint interaction causing intense pain
B) abnormal ligament or bone structure results in delivery of excessive force to a joint; this requires more counteracting muscle effort leading to premature/excessive muscle fatigue in an attempt to absorb shock/ decelerate involved part.
C) As muscle fatigues bone fracture and joint injury increase due to increased frequency of unguarded unexpected movement when muscles are to week or unprepared to accommodate load.
D) The force applied to these weakened joints is often within normal limits but the force may cause injury without proper dampening effects of muscle.
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Popliteus Origin
ORIGIN: As the most proximal member of the deep posterior compart-ment of the knee it arises from the lateral aspect of the lateral femoral condyle, adjacent arcuate ligament and posterior capsule; the popliteofibular ligament forms along its anterolateral margin
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Popliteus Insertion
INSERTION: It courses obliquely inferomedially to insert on the posterior aspect of the proximal tibia above the popliteal/soleal line; it also attaches to the lateral meniscus as it crosses lateral to medial
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Popliteus innervation
INNERVATION: Tibial n (L4-S1)
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Popliteus action
ACTION: Internally rotates tibia in an open kinetic chain and externally rotates the femur when the tibia is fixed (closed kinetic chain); and assists knee flexion; it functions primarily as a knee stabilizer
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Popliteus key kinesiologic function
KEY KINESIOLOGIC FUNCTION: It unlocks the externally rotated tibia when flexion is initiated from a fully extended position (“unlocks the screw home”); it may be the most important stabilizer of the lateral side of the knee; it is important to stabilizing the knee at extremes of external tibial rotation through its action and by tensing the important popliteofibular ligament; it stabilizes the tibia when squatting by limiting anterior femoral slide and internal tibial rotation; it may also help posterior translation of the lateral meniscus during flexion & external rotation protecting it from being crushed during these actions; also assists quadriceps in resisting posterior translation of the tibia
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Popliteus Muscle Test
VECTOR: Both hands of examiner are active – upper hand rotates thigh medially & lower hand rotates leg laterally.PT supine w/ knee flexed ~20º & tibia internally rotated; PT stabilizes self
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SEMITENDINOSUS origin
ORIGIN: Ischial tuberosity; its tendon shares a “common origin” w/ tendons of the semimembranosus & biceps femoris (long h.)
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Semitendinosus insertion
INSERTION: Proximal medial surface of the shaft of the tibia just inferior to the medial condyle as the posterior portion of the pes anserinus (along w/ the sartorius & gracilis)
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Semitendinosus innervation
INNERVATION: Tibial division sciatic nerve (L5-S2; primarily L5)
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Semitendinosus action
ACTION: Primarily knee flexion (w/ biceps & semimembranosus) & when the knee is flexed it internally rotates the tibia (along w/ semimembranosus, gracilis, sartorius & popliteus); also assists extension & internal rotation @ the hip
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Semitendinosus Key Kinesiologic Function
KEY KINESIOLOGIC FUNCTION: Important to deceleration of the limb @ the end of the forward swing during the gait cycle and when kicking, and is also stretched and vulnerable to injury @ the end of forward swing during ballistic activities; provides dynamic stabilization across the knee resisting anterior tibial translation and thus protects the ACL, and resists external tibial rotation; also assists the quadriceps in the last stages of extension in a closed kinetic chain (= paradoxical extension)
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Semimembranosus origin
ORIGIN: Ischial tuberosity along with the semitendinosus & long head of the biceps femoris (“common hamstring origin”)
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semimembranosus insertion
INSERTION: Posterior aspect of the medial tibial condyle; also it has significant attachment to the posterior knee joint capsule and its tendon is the anchoring point of the inferomedial end of the oblique popliteal ligament (OPL); it also appears to have attachments to the posterior horn of the medial meniscus
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Semimembranosus innervation
INNERVATION: Tibial division sciatic nerve (L5-S2; primarily L5)
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Semimembranosus action (same as semitendinosis)
ACTION: Primarily knee flexion (w/ biceps & semimembranosus) & when the knee is flexed it internally rotates the tibia (along w/ semimembranosus, gracilis, sartorius & popliteus); also assists extension & internal rotation @ the hip
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Semimembranosus key kinesiologic function
KEY KINESIOLOGIC FUNCTION: Essentially the same as the semitendinosus; it dynamically supplements the ACL by resisting anterior tibial translation; it may assist in posterior translation of the medial meniscus during flexion similar to the effect of the popliteus on the lateral meniscus; its effect on the OPL is unclear; note that the semimembranosus & semitendinosus are injured less frequently than the biceps femoris
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SEMITENDINOSUS & SEMIMEMBRANOSUS muscle test
Examiner contacts medial ankle & pushes towards PT is prone w/ thigh adducted/internally rotated w/ knee flexed and internally rotated & foot relaxed. PT is prone w/ thigh adducted/internally rotated w/ knee flexed and internally rotated & foot relaxed
80
Biceps femoris origin
ORIGIN: 2 heads
Long head originates from the ischial tuberosity as part of the common tendon with the semitendinosus & semimembranosus
Short head originates from the lateral lip of the distal ½ of the linea aspera and lateral supracondylar line of the femur, and from the lateral intermuscular septum
81
biceps femoris insertion
INSERTION: Primarily the superolateral aspect of the fibular head with slips to the lateral tibial condyle and fibular collateral ligament
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biceps femoris innervation
INNERVATION: Sciatic - tibial division to the long head and peroneal/fibular division to the short head ( L5-S2; primarily S1)
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biceps femoris action
ACTION: Flexion @ the knee and when the knee is flexed it externally rotates the leg; the long head also assists extension and external rotation @ the hip
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biceps femoris key kinesiologic function
KEY KINESIOLOGIC FUNCTION: It is the most injured hamstring; it eccentrically decelerates the forward swinging limb and is most vulnerable to injury @ the end of the swing phase; it supplements the ACL by dynamically resisting anterior tibial translation; it also assists the quadriceps by paradoxically extending tibia @ terminal extension
85
biceps femoris muscle test
VECTOR: Examiner pushes towards knee extension...PT prone w/ knee flexed & externally rotated & w/ thigh abducted/externally rotated
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sartorius origin
ORIGIN: Anterior superior iliac spine (ASIS) and adjacent notch
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sartorius insertion
INSERTION: It passes obliquely inferomedially across the thigh and posterior to the medial femoral condyle. It contributes the anterior portion of the pes anserine tendon along with the gracilis & semitendinosus; it inserts on the medial aspect of the proximal end of the shaft of the tibia just below the medial tibial condyle
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sartorius innervation
INNERVATION: Femoral nerve (L2-L3)
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sartorius action
ACTION: Flexes, and internally rotates @ the knee; flexes, abducts and externally rotates @ the hip
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sartorius key kinesiologic function
KEY KINESIOLOGIC FUNCTION: Forms a force couple with the gracilis and semitendinosus @ the knee; if it were able to act alone it would position the lower limb in the “figure 4” or “tailor’s” position; note that it forms the anterior “roof” of the adductor canal; may assist ACL by resisting anterior tibial slide
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sartorius muscle test
Examiner pushes medially w/ upper hand...Examiner also pulls w/ lower hand...Patient is in figure 4 position AND stabilizes self by holding table
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rectus femoris origin
ORIGIN: It has 2 origins; the straight tendon arises from the anterior inferior iliac spine (AIIS) and the reflected tendon originates just superior to the brim of the acetabulum and adjacent hip joint capsule
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rectus femoris insertion
INSERTION: It forms the anterior middle part of the quadriceps tendon attaching to the superior pole of the patella and ultimately inserts on the tibial tuberosity by way of the infrapatellar tendon
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rectus femoris innervation
INNERVATION: Femoral nerve (L2-L4)
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rectus femoris action
ACTION: It extends @ the knee along with the other 3 heads of the quadriceps, and flexes @ the hip; this is the only part that crosses the hip (note that it also flexes the trunk @ the hip)
96
rectus femoris key kinesiologic function
KEY KINESIOLOGIC FUNCTION: One of the prime movers that flex @ the hip, especially above 70º (“high steppers”); the proximal muscle tendon junction of the rectus is the most commonly strained region of the quadriceps and is especially vulnerable to injury at the end of posterior swing when running
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rectus femoris muscle test
EXAMINER pulls towards hip extension...
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vastus intermedius origin
ORIGIN: It arises deep to the rectus femoris from the anterolateral surface of the proximal 2/3 of the shaft of the femur and the distal part of the lateral intermuscular septum
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vastus intermedius insertion
INSERTION: It forms the deep part of the quadriceps tendon attaching to the superior & lateral borders of the patella and ultimately inserts via the infrapatellar tendon to the tibial tuberosity and the by the lateral retinaculum to the lateral tibial condyle; the deep layer of this muscle referred to as the “articularis genu” inserts on the suprapatellar pouch/bursa
100
vastus intermedius innervation
INNERVATION: Femoral nerve (L2-L4; especially L3-L4)
101
vastus intermedius action
ACTION: Extends the leg @ the knee joint
102
vastus intermedius key kinesiologic function
KEY KINESIOLOGIC FUNCTION: Its contribution to the lateral retinaculum effects the position of the patella; the articularis genu pulls the suprapatellar bursa proximally presumably to protect its synovial lining from being pinched by the patella during extension @ the knee
103
vastus intermedius muscle test
Examiner palpates quads during test..Examiner pushes down towards knee flexion
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1. How many articular surfaces does a simple joint have?
A) 2 articular surfaces comprising 1 articulation
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How many articular surfaces does a compound joint have?
A) 2 or more articulations B) ex: subtalar joint with ant/post glide, medial/lateral rotation, medial/lateral tilt and distraction
106
How does a compound joint differ from a complex joint?
A) A complex joint is 1 or more articulations plus intra-articular disc/meniscus ex: knee or ulnocarpal B) Compound joint has 2 or more articulations with no intra articular disc/meniscus
107
How does a joint complex differ from a complex Joint?
A) Joint complex is several joints acting together as a functional group while a complex joint is 1 or more articulations plus intra-articular disc/meniscus
108
What are the 6 anatomical joint classifications?
A) Spheroid/ enarthrosis/ ball and socket B) ellipsoid/condyloid C) arthroid/planar/gliding D) ginglymus/ hinge
E) trochoid/pivoit
109
What are the 4 joint motion classification (based on traditional physiological categories)
A) Angular, translational, rotational, and circumduction
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What are the 4 classifications based on axes of motion (degrees of freedom/planes of movement)?
A) Uniaxial, biaxial, polyaxial, and nonaxial
111
The Glenohumeral and acetabulofemoral joints are examples of what category of anatomical joint?
A) Synovial ball and socket joint permitting movement in all planes as well as rotational movement.
112
The shoulder and hip joints are polyaxial joints with how many degrees of freedom?
A) Degrees of freedom describe the number of axes in which a joint is able to move (X, Y, Z) axes B) The shoulder as three degrees of freedom and can produce 8 different movements C) Hip joint has three degrees of freedom (DOF)
113
The ankle, elbow and interphalangeal joints are examples of what category of anatomical joint?
A) All are example of hinge joints or ginglymus joints
114
The talocural, ulnohumeral and interphalangeal joints are uniaxial joints with how many degrees of freedom?
A) Uniaxial= 1 degree of freedom
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Define the 4 joint motion classifications (the traditional physiological classifications)
A) Angular motion includes flexion, extension, abduction, adduction B) Translation (primiarly gliding) and is non angular C) Rotational (not spin) and is non angular but moving around a central axis
D) Circumduction is a combination of all of the above motions (angular, translation, rotation)
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13. Give an example of a uniaxial, biaxial, polyaxial and nonaxial joints?
A) Uniaxial: 1 plane ex. elbow B) Biaxial: 2 planes ex. knee C) Polyaxial: many planes ex. shoulder D) Nonaxial: no planes, gliding type joint ex: intercarpal
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Give an example of of a gliding joint?
A) Gliding joint= primarily translation type movement or non angular motion B) Ex: Intercarpal joint
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Give an example of a rotational joint?
A) Rotational joint (not spin)= moving a bone around an axis (non angular movement) B) ex: Atlas-Dens articulation (rotating head left and right) C) ex: hip joint
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Give an example of each of an arthroid joint?
A) Arthroid joint is a joint where both opposing surfaces glide relative to one another B) ex: acromioclavicular
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Give an example of a complex joint?
A) Complex joint= 1 or more articulations plus intra-articular disc/meniscus
B) ex: knee or ulnocarpal joints
121
Give an example of a trochoid joint?
A) Trochoid= pivot joint
| B) ex: proximal radio-ulnar joint
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Give an example of each of a sellar joint?
A) Sellar= saddle joint, the movements are the same as a condyloid joint and displays circumduction B) usually biaxial joints where a concave surface articulates with a convex surface C) ex. carpometacarpal joints and the sternoclavicular joint
123
Give an example of an enthrosis joint?
A) Enthrosis= spheroid joint= ball and socket B) ex: shoulder (also has some gliding motion)
124
Give an example of each of a ellipsoid joint?
A) ellipsoid=condyloid (often bicondylar) joint where a condyle is received in an elliptical cavity permitting
movement in two planes B) ex: metacarpophlangeal joints, wrist joint
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Why is there no such thing as a true hinge in the human body?
A) Hinge joint = ginglymus joint B) Hinge joints are usually accompanied by gliding (translation) movement
126
What is conjoint rotation of the knee?
A) Screw home mechanism, which is external rotation seen in the last few degrees of knee extension B) as you extend the knee the joint “screws” into place (aka rotates) which is seen in the last few degrees of
extension
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What is the significance of no flat articular surfaces?
A) Most joint surfaces are irregular and ovoid in shape.
| B) The significance is that this allows for nonlinear accessory motions between joint surfaces
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What are the significances of no straight bones?
A) Most bones are crooked or crank shaped bones which allows actions to differ from joint motion
B) ie. different shape of bone allowing unique joint motion
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26. What is osteokinematic movement base on?
A) Osteokiematics is based on the mechanical axis of rotation (not the axis of anatomical axis rotation)
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27. Define Spin.
A) Spin: stationary mechanical axis (does not equal rotation). However, Spin may lead to rotation when mechanical axis is parallel to long axis (shaft) of bone. Usually, spin does not equal rotation because bones are crooked/crank shaped where the mechanical axis does not parallel the long axis of rotation.
B) Spin usually accompanies swing
C) when spin occurs you will see a swinging movement of the long bone
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28. Define Swing.
A) Swing: mechanical axis of rotation moves on a stationary surface
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29. Does pure swing or pure spin occur?
A) Pure spin and Pure swing are very rare and/ or does not occur
B) Swing and spin occur almost always at the same time creating an accessory motion
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30. What is an impure swing?
A) Spin and swing occur together
134
31. Is impure swing very common?
A) Yes.
135
32. What is a chord?
A) Chord is a swing motion in a uniform curve ie. geodesic
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33. What is an arc?
A) Arc is swing motion in a non uniform curve ie. Non-geodesic
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34. What is the screw home mechanism and where does it occur?
A) Screw home mechanism is where a joint rotates externally in the last few degrees of motion “locking” it into place.
B) During the last 20 degrees of knee extension, anterior tibial glide (on the femur) persists on the tibias
medial condyle because its articular surface is long in that dimension than the lateral condyles. Prolonged
anterior glide on the medial side produces external tibial rotation ie. The “screw home mechanism”
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35. What does the screw home mechanism tighten and when?
A) The screw home mechanism tightens the knee joint via external rotation of the tibia in the last few degrees of extension
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36. What muscle reverses the screw home mechanism?
A) Then the popliteus muscle B) origin at lateral femoral epicondyle, which is deep to lateral collateral ligament and insertion at the
posterior medial tibia) creates minimal flexion of knee. C) Creates: external rotation of the femur when the foot is fix (ie. standing) D) Creates: internal rotation of the tibia when the foot is free (ie. sitting) E) the knee is a modified hinge joint due to the small amount or rotation found in terminal degrees of
movement
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37. Define tight packed position of joints.
A) The joint is in a closed or locked position
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38. Define loose packed position joints.
A) The joint is in an open or unlocked position. This is where joint play occurs.
B) Any other position than tight/closed packed
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39. Define Conjunct joints.
A) Conjoint rotation ie. A little bit of externally rotation is seen as extension occurs
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40. Define resting joints.
A) The most loose packed position
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41. Define anatomical and neutral position of joints.
A) Anatomical position: the standard position of joints of a human standing upright with arms externally rotated and thumbs facing laterally.
B) neutral position: standard zero degrees when measuring range of motion (paired antagonistic motions)
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42. Are there any other names for these positions? Are these names synonymous?
A) No these names are not synonymous
| B) There are other names for these positions
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43. What is arthrokinematic motion based on?
A) Arthrokinematic motion is based on movement at articular surfaces or small amplitude motion of bones at joint surfaces. Examples of movements would be roll, glide (or slide), and spin
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44. Is Arthrokinematic motion the same as osteokinematic motion?
A) No they are not the same. B) Osteokinematic motion is based on the mechanical axis of rotation. See gross movement of bones at joints.
Example of movements would be flexion, extension, abduction, adduction, internal rotation, external
rotation
148
45. How do arthrokinematic and osteokinematic motion differ?
A) Arthrokinematic motion occurs at joint surfaces. B) Osteokinematic motion is the gross movement of bones around joints. So the motion that we see produced
by muscle contracting and moving bone around joints.
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46. What is the accessory rotation that accompanies angular movement called?
A) Conjunct or conjoint rotation, which is a combination of roll, slide and spin
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47. Define roll.
A) Rolling of one joint surface on another
| B) multiple points along one rotating joint surface contact multiple points on another joint surface
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48. Define slide.
A) Linear translation of a joint surface parallel to the plane of adjoining joint surface B) A single point on one joint surface contacts multiple points on another joint surface (like a skid across a
surface)
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49. Define Spine.
A) Rotational movement of a joint surface on the fixed adjacent surface. B) A single point on one joint surface rotates on a single point on another joint surface.
C) Occurs about a central longitudinal axis of rotation. (think of a spin tip spinning on surface)
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50. How does roll and slide occur when a convex surface is moving? (think convex rule)
A) Concave/convex rule is used to establish joint stability B) When the convex surface is moving roll and slide occur in opposite direction C) The convex joint surface slides in the opposite direction of the roll on the concave surface
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51. When the convex surface is moving, which motion is in the same direction as the angular motion (roll/slide)?
A) Roll is in the same direction of angular motion
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52. When the convex surface is moving, which is in the opposite direction as angular motion (roll or slide)?
A) Slide is in the opposite direction of angular motion
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53. Describe how roll and slide occur when a concave articular surface is moving. Are they in opposite or same direction? (Think concave rule)
A) When the concave joint surface is moving roll and slide are in the same direction and occur
simultaneously.
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54. When the concave surface is moving, what direction is roll and slide relative to angular motion?
A) Roll and slide are in the same direction as angular motion = progression
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During gliding movement does roll occur?
No, only slide occurs
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56. During rotational movement does roll or slide occur?
A) Yes, both occur (in the same or opposite direction depending on which surface concave/convex is fixed)
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57. Relative to the concave convex rule, why is the convex surface always bigger than the concave surface?
A) To prevent the convex surface from falling off the concave surface.
B) the gliding movement is in the opposite prevents the convex surface from falling off the concave surface.
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58. Give an example of a joint demonstrating the concave rule?
A) Concave rule: concave surface moves, roll and slide in the same direction.
B) The knee joint. The concave tibia is the moving surface against a convex surface of the fixed femur.
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59. Give an example of a joint demonstrating the convex rule?
A) Convex rule: convex surface moves. Roll and slide in opposite directions. B) The shoulder joint. The humerus is the convex moving surface. The glenoid fossa is the concave fixed
surface.
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60. Define open vs. closed kinetic chain.
A) Open: exercises that are performed where the hand and foot are permitted to move
B) Closed kinetic chain: exercises that are performed where the hand and foot are fixed (not able to move)
