Kinesiology Flashcards
Test 1
1
Q
What is kinesiology the study of?
A
Movement
2
Q
What is a branch of biomechanics that describe the motion of a body WITHOUT regard to forces that produce the motion?
A
Kinematics
3
Q
What are the 2 types of kinematics?
A
Translation and rotation
4
Q
What are the two types of translation?
A
rectilinear and curvilinear
5
Q
Translation or rotation? All parts of the body move in the same direction
A
translation
6
Q
Example of rectilinear translation?
A
Walking in straight line, people riding in elevator, ball rolling down a path
7
Q
Example of curvilinear translation?
A
Cycling, turning of car, arc of ball being throw, roller coaster, running on a curved racetrack
8
Q
T or F? In walking, translation and rotation occur?
A
TRUE - the center of mass moves forward together (translation) but rotation of limbs is required to move forward and achieve the translation
9
Q
What is the term for motion of bones relative to cardinal planes?
A
Osteokinematics
10
Q
What is the term for the pivot point about which joint motion occurs?
A
Axis of rotation
11
Q
T or F? Axis of rotation is parallel to the plane of motion
A
FALSE - axis of rotation is perpendicular to the plane of motion
12
Q
What are the 3 axes of rotation?
A
Anterior-posterior (frontal plane)
Medial-lateral (sagittal plane)
Vertical/longitudinal (horizontal plane)
13
Q
Open or closed chain motion? Movement of distal segment of bone about a relatively fixed proximal segment. Ex. sitting down and kicking legs
A
Open chain motion
14
Q
Open or closed chain motion? Movement of proximal segment of bone about a relatively fixed distal segment. Ex. Squats
A
Closed chain motion
15
Q
Arthrokinematics or osteokinematics? Describes only the path of the moving bones (flexion/extension, abduction/adduction, etc). Ex. door swings open in the horizontal plane
A
Osteokinematics
16
Q
Arthrokinematics or osteokinematics? Describes the motion between the articular surfaces of joints. Ex. spinning of a hinge
A
Arthrokinematics
17
Q
What are the two benefits of a convex-concave joint relationship?
A
- Improves fit and stability
- Properly guides motion
18
Q
What are the 3 movements between joint surfaces (arthrokinematics)?
A
Roll, slide, and spin
19
Q
For convex on concave joint, does the roll and slide movement occur in the same or opposite direction?
A
Opposite
Ex. Abduction of shoulder - humerus rolls upward in socket and slides downward
20
Q
For a concave on convex joint, does the roll and slide movement occur in the same of opposite direction?
A
Same
Ex. When sitting and kicking your leg, the concave surface of the tibia is rolling and sliding on the convex surface of the end of the femur
21
Q
What is a push or pull that can produce, modify, or halt a movement?
A
Force
22
Q
What is the branch of mechanics that describes the effect of forces on the body?
A
Kinetics
23
Q
Internal or external force? Generated within the body from a muscular contraction or passive force such as tension generated from ligamentous or muscular elongation.
A
Internal force
24
Q
Internal or external? Generated outside the body such as from gravity, a weight, or a therapist applying resistance
A
External force
25
What is the rotational equivalent of force?
Torque
26
The amount of torque generated across a joint depends on what 2 things?
1. The amount of force exerted
2. The distance between the force and axis of rotation (moment arm)
27
What is an example of a first class lever?
Head and neck
Weigh, fulcrum, Force
28
What is an example of a second class lever?
Standing on your toes
fulcrum, Weight, Force
*Internal moment arm always longer than external moment arm*
29
What is an example of a third class lever?
Bicep curl
fulcrum, Force, Weight
*Internal moment arm always smaller than external moment*
30
What is the most common type of lever in the body and what does it favor?
Third class lever - favors speed and distance
31
T or F? Line of pull describes the direction of muscular force
True
32
In a medial-lateral axis of rotation, bony motion ____ to the medial-lateral AOR will produce flexion in the sagittal plane
Anterior to the medial-lateral AOR will produce flexion in the sagittal plane
33
In a medial-lateral axis of rotation, bony motion ____ to the medial-lateral AOR will produce extension in the sagittal plane
Posterior to the medial-lateral AOR will produce extension in the sagittal plane
34
In then anterior-posterior AOR, line of pull passing superior or lateral to the axis will produce ____ in the frontal plane
Abduction in the frontal plane
35
In the anterior-posterior AOR, line of pull passing inferior or medial to the axis will produce ____ in the frontal plane
Adduction in the frontal plane
36
In the vertical axis of rotation, anterior or medial pull produces ____
INTERNAL rotation
37
In a vertical axis of rotation, posterior or lateral pull produces ____
EXTERNAL rotation
38
In kinetics, what represent the magnitude and direction of a force, which can be combined (resultant)
Vector
39
T or F? Direction of a force represented by a vector is indicated by the orientation of the arrowhead.
True
40
T or F? The magnitude of a force is indicated by the relative length of the vector line
True
41
What parts of the body does the axial skeleton contain?
Skull, hyoid bone, spine, ribs, sternum
42
What parts of the body does the appendicular skeleton contain?
Extremities and scapula and pelvis
43
What is compact bone also called?
Cortical bone
44
Cortical (compact) or cancellous (spongey) bone? Dense and extremely strong, lines the outermost part of a bone, and absorbs compressive forces
Cortical (compact) bone
45
What is spongy bone also called?
Cancellous bone
46
Cortical (compact) or cancellous (spongy) bone? Porous and lightweight, composes inner bone portions, and redirects forces toward weight bearing sources
Cancellous (spongy) bone
47
Diaphysis or epiphysis? Central shaft of the bone, a thick hollow tube made of cortical (compact) bone
Diaphysis
48
Diaphysis or epiphysis? Ends of the bone, composed of spongy bone mainly, and transmits weight bearing forces across the body
Epiphysis
49
What lines the articular surfaces of each epiphysis acting as shock absorber between joints?
Articular cartilage
50
What is the thin, tough membrane called covering long bones where muscles and ligaments attach?
Periosteum
51
What is the central hollow tube within the long bone diaphysis called that stores bone marrow and provides a passage for arteries?
Medullary canal
52
What is the membrane called that lines the medullary canal surface and houses cells that are important for forming and repairing bones?
Endosteum
53
What type of bone, long, short, flat, or irregular, has an obvious axis or shaft and has an expanded bone portion at each end?
Long bone
Ex. femur, humerus, radius
54
What type of bone, long, short, flat, or irregular, has a length, width, and height that are about equal?
Short bone
Ex. carpal bones of hand
55
What type of bone long, short, flat, or irregular has a wide variety of shapes and sizes and can be a sesamoid (similar look to a sesame seed)?
Irregular bone
Ex. patella, vertebra bones
56
What type of bone, long, short, flat, or irregular is typically flat or slightly curved and is often the base for many muscle attachments?
Flat bone
Ex. scapula, sternum
57
What type of joint is a junction between bones allowing little to no movement?
Synarthrosis
58
What is the primary function of synarthrotic joints?
to firmly bind bones together and transmit forces from one bone to another
59
Examples of synarthrotic joints?
Fibrous:
-Suture (skull sutures)
-Gomphosis (teeth joint)
Cartilaginous:
- Synchondrosis (where ribs meet sternum)
60
What type of joint is a junction between bones allowing limited amounts of motion?
Amphiarthrosis
61
what are amphiarthrotic joints primarily composed of?
fibrocartilage and hyaline cartilage
62
What is the primary function of amphiarthrotic joints?
Provide shock absorption
63
Examples of amphiarthrotic joints?
Fibrous:
- Syndesmosis (interosseous membrane)
Cartilaginous:
-Symphysis (pubic symphysis)
64
What type of joint is a junction between bones allowing free movement?
Diarthrosis or a synovial joint
65
How many synovial/diarthrotic joints are there?
7
66
Which joint type is an articulation that contains a fluid-filled joint cavity between two or more bones?
Diarthrotic/synovial joint
67
What are the 7 common elements of synovial joints?
1. synovial fluid
2. articular cartilage
3. articular (joint) capsule
4. synovial membrane
5. capsular ligaments
6. blood vessels
7. sensory nerves
68
Which element of a synovial joint provides joint lubrication and nutrition?
synovial fluid
69
Which element of a synovial joint dissipates and absorbs compressive forces?
articular cartilage
70
Which element of a synovial joint is connective tissue that surrounds and binds the joint together?
articular (joint) capsule
71
Which element of a synovial joint produces synovial fluid?
synovial membrane
72
Which element of a synovial joint is thickened regions of connective tissue that limits excessive joint motion?
capsular ligaments
73
Which element of a synovial joint transmits signals regarding pain and propricoception?
sensory nerves
74
Which synovial joint type allows motion in only one plane about a single axis of rotation, similar to the hinge of a door?
Hinge joint
Ex. humeroulnar joint (elbow) - flexion and extension
75
Which synovial joint allows rotation about a single longitudinal axis of rotation, similar to the rotation of a door knob?
Pivot joint
Ex. proximal radioulnar joint - supination and pronation
76
Which synovial joint has a convex elongated surface on a concave surface, allowing motion to occur in two planes?
Ellipsoid/condylar joint
Ex. radiocarpal joint (wrist) - flexion and extension and abduction and adduction
77
Which synovial joint allows wide ranges of motion in all three planes and is an articulation between a spherical convex surface and a cup like socket?
Ball and socket joint
Ex. hip or shoulder - flexion and extension, abduction and adduction, internal and external rotation
78
Which synovial joint allows limited motion but can slide and rotate in many directions and is an articulation between two relatively flat bony surfaces?
Plane/gliding joint
Ex. intercarpal joints of the hand - flexion and extension, abduction and adduction
79
Which synovial joint allows extensive motion in 2 planes and is one concave surface on one convex surface?
Saddle joint
Ex. CMC joint of thumb - flexion and extension, abduction and adduction
80
Which synovial joint is an articulation between a large, rounded, convex member and a relatively shallow concave member with 2 degrees of freedom?
Condyloid/ellipsoid joint
Ex. tibiofemoral joint (knee) - flexion and extension and internal and external rotation
81
What are the 3 things that all connective tissues of joints of the body are consisted of and are mixed in various proportion depending on the joints function?
Fibers (collagen 1 and 2 and elastin), ground substance, and cells
82
Type 1 or type 2 collagen fibers? Thick and rugged that resist elongation and compose ligaments, tendons, and fibrous capsules?
Type 1 collagen fibers
83
Type 1 or type 2 collagen fibers? Thinner and less stiff that are found mainly in cartilage and provide a flexible woven framework for painting general shape and consistency of structures
Type 2 collagen fibers
84
What fiber is elastic in nature, resist forces but can have give when elongated, can be useful in preventing injury b/c of its flexibility, and is found in large arteries, skin and lungs?
Elastin
85
Collagen and elastin fibers are embedded within what element of connective tissue?
Ground substance
86
What is ground substance primarily composed of?
Water, solutes, and glycosaminoglycans
87
What element of connective tissue allows body fibers to exist in a fluid filled environment, dispersing repetitive forces?
Ground substance
88
What are cells within connective tissue responsible for?
Responsible for maintenance and repair of tissue that make up joints
89
What are the 4 types of connective tissue binds bones together and restrains unwanted movements of joints, composes ligaments and the tough outer layer of joint capsule and is primarily made of type 1 collagen fibers with low elastin content?
dense, irregular connective tissue
Ex. MCL, patellar tendon
90
Which of the 4 types of connective tissue resists and distributes comprehensive and shear forces transferred from articular surfaces covers the ends of articulating bones in synovial joints, and has high type 2 collagen fiber content which helps anchor the cartilage to bone?
Articular catilage
91
Which of the 4 types of connective tissue provides support and stabilizes joints, provides shock absorption, composes intervertebral discs and menisci of knee, and have bundles of type 1 collagen?
Fibrocartilage
92
Which of the 4 types of connective tissues forms the primary supporting structure of the body and a rigid lever to transmit muscle force to move the body, and has arrangements of type 1 collagen to provide a framework for hard mineral salts
BONE
93
What connects MUSCLE to bone to convert muscular force into bony motion, with parallel alignment of collagen fibers?
Tendons
94
What connects BONE to bone and maintains a joint's structure, with irregular crossing patterns of collagen fibers?
Ligaments
95
Bone conformation and ligamentous networks provide what?
Static stability
96
What do muscles function as?
Active stabilizers
97
T or F? Muscles cannot respond as quickly as ligaments to an external force, but allow a graded and more controlled response
True
98
T or F? Joint immobilization doesn't affect stiffness and tissue ability to withstand forces.
FALSE - joint immobilization increases stiffness and decreases the tissue's ability to withstand forces
99
T or F? Immobilization of a joint may be necessary but can make the joint susceptible to injury/instability.
True
100
What is the sole producer of active force in the body and what is it stimulated by?
Muscle, stimulated by the nervous system to contract and pull on bone, creating movement
101
T or F? When a muscle contracts the freest (or less constrained) segment moves
True
102
What is the term for shortening or contracting of muscle where the muscle is producing active force?
Ex. upward motion of bicep curl
Concentric
103
What is the term for a muscle attempting to contract but is pulled to a longer length by a dominant external force?
Ex. Downward motion of bicep curl
Eccentric
104
What is the term for a muscle that is generating active force while remaining at constant length?
Isometric
105
What does the term *proximal attachment* also refer to?
Origin
106
What does the term *distal attachment* also refer to?
Insertion
107
What is the term for a muscle or mm group most directly related to performing a specific movement?
Agonist
108
What is the term for a mm or mm group that can oppose the action of the agonist?
Antagonist
109
What is the term for what occurs when agonist and antagonist muscles are simultaneously activated in an isometric fashion?
co-contraction
110
What is the term for muscle that "fixes" or holds a body segment relatively stationary so that another muscle can more effectively perform?
Stabilizer -
Ex. our core stabilizes so we can kick our leg forward or the rotator cuff muscles stabilizing the GH joint
111
What is the term for muscles that work together to perform a particular action?
Synergists
112
What is the term for a synergistic action occurring when muscles produce force in different linear directions but produce torque in the same rotary direction?
Force-couple
Ex. upper trap, lower trap, and serratus anterior creating upward rotation of scapula together
113
What is the term for the shortening and lengthening of a muscle, where it can shorten or elongated about half its resting length?
Excursion
114
What layer surrounds the entire belly of the mm to help hold its shape?
Epimysium
115
What is the muscle belly composed of?
Numerous fascicles
116
What is a bundle of muscle fibers called?
Fascicle
117
What is the layer that surrounds and supports individual fascicles and serves as a vehicle to support nerves and blood vessels?
Perimysium
118
What is an individual cell with multiple nuclei that contains all the contractile elements (actin/myosin) within muscle?
Muscle fiber
119
What layer is a dense collagen fibril meshwork surrounding each muscle fiber that helps transfer contractile force to the tendon?
Endomysium
120
What composes muscle fiber?
Myofibrils
121
What is the basic contractile unit of muscle fiber
Sacromere
122
What 2 elements are sarcomeres made up of?
Actin and myosin
123
What is the hypothesis called that states actin filaments slide past myosin head filaments, resulting in contraction of an individual sacromere?
Sliding filament hypothesis
124
What is created when myosin filaments with numerous heads attach to thinner actin filaments?
actin-myosin cross bridges
125
What happens in actin-myosin cross bridges?
Myosin heads bind an actin filament, flexes, and produces a power stroke. The actin filament slides past the myosin, generating force and shortening a sarcomere. Simultaneous contraction of sarcomeres shortens the entire muscle.
126
What 3 factors determine functional potential of a muscle?
1. Cross-sectional area
2. Shape
3. Line of pull
127
T or F? The larger a muscle's cross sectional area, the greater its force potential?
True - a person with bigger muscles can generate larger force
128
What are the 4 main muscle shapes?
Fusiform (biceps brachii)
Triangular (gluteus medius)
Rhomboidal (gluteus max)
Pennate (rectus femoris)
129
Which muscle shape has fibers that run parallel to one another and are built to provide large ranges of motion?
Fusiform (large ROM)
ex. biceps brachii
130
Which muscle shape has many origins converging to a small distal attachment and provides a stabilized base for generating force?
Triangular (create force)
Ex. gluteus medius
131
Which muscle shape that has many origins and insertions and is shaped like a rhomboid or offset square? Also is suited to stabilize a joint or provide large forces, depending on its cross-sectional area
Rhomboidal (stabilize joint and create force)
ex. gluteus max
132
Which muscle shape is like a feather, muscle fibers approach central tendon at oblique angle, large force but limited ROM, and can be classified based on the number of fiber sets attached to a central tendon?
Pennate (large force, limited ROM)
Ex. rectus femoris
133
What is the difference between muscle shapes with parallel fibers and muscle shapes with pennate/oblique fibers?
Parallel muscles have a small cross section + small force, but can have large length change
Pennate muscles have a large cross section = large force, but have small length change
134
Muscle forces can be described as ____ because they possess both magnitude and direction
Vectors can describe muscle forces b/c they have magnitude and direction
135
Direction of a muscle's force is referred to as ____
line of pull
136
T or F? The length-tension relationship of muscle significantly impacts force output of muscle
True
137
Active or passive length-tension relationship? Force generated is highly dependent on sarcomere length
Active length - tension relationship
138
T or F? Muscles that are passively used and stretched rapidly to extreme length often become injured as well as the tendons or bony attacments
TRUE
139
What is the term for a mm that crosses 1 joint?
Mono-articular
140
What is the term for a mm that crosses 2 joints?
multi-articular
141
Can a multi-articular or mono-articular muscle be elongated more?
multi-articular
142
Active or passive insufficiency? Filaments overlap so potential for cross bridge is greatly reduced - the action is weakened or limited b/c the mm becomes too short to produce a useful or effective force
Active insufficiency
143
Active or passive insufficiency? Actin is out of range of the myosin so cross bridging is greatly reduced - action is weakened or limited b/c the antagonist mm is passively overstretched, preventing full ROM and strength
Passive insufficiency
144
Does active/passive insufficiency describe one or two joint mms?
Two jt mms
145
Active or passive insufficiency? The muscle is too short.
Active insufficiency
146
Active or passive insufficiency? The muscle is overstretched or too long.
Passive insufficiency
147
Maximally flexing the hip while keeping knee straight.
- Motion is passively being limited by what muscle?
- Motion is actively being limited by what muscle?
Motion is passively being limited by the hamstrings.
Motion is actively being limited by rectus femoris
148
Maximal hip extension with knee flexion.
- Motion is passively being limited by what muscle?
- Motion is actively being limited by what muscle?
Motion is passively being limited by rectus femoris.
Motion is actively being limited by hamstrings.
149
T or F? When measuring a muscle, you do not want there to be any active or passive over-stretching or shortening of any muscle?
True
150
T or F? A muscle during concentric contraction produces more force as speed of contraction increases?
FALSE - mm produces less force as the speed of contraction increases
Why? At higher speeds of contraction, actin-myosin cross bridges lack enough time to form, pull, and reform, so force is decreased
151
____ contraction creates greater force than any speed of concentric contraction?
Isometric
152
During an ____ contraction, passive force production increases slightly as the speed of elongation increases.
Eccentric
This can explain why you often feel greater mm soreness after high velocity eccentric activities
153
T or F? Muscles held in a shortened position will shorten and muscles held in an elongated position will lengthen
True
154
What is the term for a mm that is so tight that is severely restricts joint movement?
Contracture
155
What can result in some degree of adaptive shortening?
Disease, poor posture, immobility
156
T or F? An overly tight muscle causes the associated joints to assume a posture that mimics that muscle's primary actions
True
Ex. a tightened hamstring causes hip extension and knee flexion
157
T or F? To optimally stretch a muscle, the therapist has to hold the limb in a position that is opposite of all of its actions
True
158
What does the overload principle imply?
A muscle must receive enough level of resistance to stimulate hypertrophy (size increase)
159
What is the term for how a muscle adapts to the way in which it is challenged?
Ex. If you only strengthen the biceps by isometrically holding a weight a 90 degrees, the muscle only strengthens at that degree
Training specificity
160
T or F? While ligaments and muscles stabilize joints, only muscles can adapt to immediate and long term external forces that interrupt the body.
True
161
How do PTs and PTAs often improve stability of a joint?
By strengthening its surrounding mms
162
T or F? Injury such as ligamentous rupture can significantly destabilize a joint
True
163
T or F? Rarely do mms work individually, but as a group?
T
164
What are the 4 joints of the shoulder complex?
Sternoclavicular, acromioclavicular, scapulthoracic, and glenohumeral
165
What is the only direct bony attachment of the upper extremity to the axial skeletion?
Sternoclavicular joint
166
T or F? The SC joint is stable but also allows extensive mobility
True
167
T or f? The SC joint's high degree of stability explains why fractures of the clavicle occur less than dislocations of the joint
FALSE - the sc joint's high degree of stability explains why fractures of the clavicle occur MORE than dislocations of the joint
168
What type of synovial joint is the AC joint?
Saddle - convex and concave surface
169
The SC joint allows movement in all 3 planes - what are these movements?
Elevation and depression, protraction and retraction, and rotation
170
In terms of the SC joint, when the clavicle is elevating and depressing, what plane is this in?
Frontal
171
How many degrees of clavicular elevation and depression are there?
Elevation - 45 degrees
Depression - 10 degrees
172
In terms of the SC joint, when the clavicle is protracting and retracting, what plane is this in? What axis of rotation?
Horizontal plane (transverse) and vertical axis rotation
173
How many degrees can the clavicle protract and retract?
15-30 degrees
174
In regards to the SC joint, what motion has to occur with the arm so the clavicle posteriorly rotates?
Shoulder has to abduct for the clavicle to post rotate. Clavicle post rotates b/c the coracoclavicular ligament becomes taut and spins the clavicle posteriorly
175
In regards to the SC joint, what motion has to occur with the arm so the clavicle will anteriorly rotate?
When the shoulder goes back to resting position form ABD
176
What axis of rotation does anterior and posterior clavicular rotation occur in?
Longitudinal axis
177
Is the scapulothoracic joint a true joint?
No
178
What muscles are elevators of the scapula? (3)
Upper traps, levator scapulae, and rhomboids - these mms support proper st posture
179
T or f? Upper traps and rhomboids have opposite rotation action, but this cancels during contraction and produces elevation of the scaupla
True
180
What mm are scapular/shoulder girdle/humerus depressors which results in shoulder depression? (4)
Lower trap, lat dorsi, pectoralis minor, and subclavius
181
T or F? The shoulder depressor mms can be used in reverse action in instances like using a walker or crutch walking?
TRUE - the can elevate the thorax (o -> i)
182
What 3 muscles work together as a force couple to produce scapular upward rotation?
Upper trap, lower trap, and serratus anterior
183
What muscles creates scapulothoracic protraction?
Serratus anterior
184
What activities do we use the serratus anterior for?
Forward reaching and pushing activities
185
What is a sign of a weakened serratus anterior and during with activity do we see it?
"winging" effect - where the medial border of the scapula is lifting away from the rib cage
186
What activity can we do to strengthen the serratus anterior if someone has winging?
push up plus
187
What are the downward rotators of the scapula? (4)
Rhomboids, pec minor, lat dorsi, and levator scapula
188
What mms are scapular retractors? (2)
Rhomboids and middle traps
189
What activities do we use our scapular retractor mms in?
Rowing or pulling
190
What kind of joint is the acromioclavicular joint?
gliding or plane joint
191
AC joint has 3 degrees of freedom - what are its movements?
Upward and downward rotation (with the upward and downward rotation of the scapula - frontal plane
Anterior and posterior tilt (sagittal plane)
Internal and external rotation (horizontal plane)
192
What structures support the GH joint?
- Rotator cuff mms
- GH joint capsule
- Coracohumeral ligament
- Glenoid labrum
- Long head of biceps
193
How many degrees of shoulder abduction is there?
120 degrees
194
Full 180 degrees of shoulder abduction is obtained how?
Full 180 degrees of shoulder abduction is obtained by combining 60 degrees of scapular upward rotation
195
During abduction of the GH joint, does the roll and slide occur in the same direction?
NO - this is convex on concave, the roll is superior while the slide is inferior
196
During adduction of the GH joint, does the humerus roll inferiorly and slide superiorly?
Yes - it is convex on concave
197
What would happen if there was no inferior slide during abduction of the shoulder?
Impingement - the humeral head would jam into the acromion , smashing the bursa
198
T or F? GH flexion and extension happens in the sagittal plane while the humeral head spins about a relatively fixed axis
True
199
The GH joint can flex how many degrees?
120
200
The GH joint can extend to how many degrees?
60
201
T or F? 180 degrees of shoulder flex is obtained by using about 60 degrees of scapular rotation
True - 2:1 ratio
202
During internal rotation of the GH joint, what ways does roll and slide occur?
GH joint rolls anteriorly and slides posteriorly
203
External rotation of GH joint, what ways does roll and slide occur?
GH joint rolls posteriorly and slides anteriorly
204
How many degrees of horizontal abduction can occur?
About 90 degrees
205
