Biomechanics Test 2 Flashcards
(136 cards)
1
Q
Elbow- Function
A
shortening and lengthening of arm for positioning of hand; provides stability for use of wrist and hand
2
Q
Forearm- Function
A
mobility through pronation/supination to assist in the positioning of the hand
3
Q
Elbow Complex- General Structure
A
uniaxial, diarthrodial hinge joint; 1 degree of freedom of motion (transverse plane); 6 ligaments and 4 muscles involved with the two joints; elbow joints and proximal radioulnar joint are enclosed in the same joint capsule
4
Q
Elbow Complex: axis of motion
A
slight angulation from medial to lateral
5
Q
Elbow Complex: Carrying Angle
A
configuration of articulating surfaces results in normal valgus angle when in extension and supination; increased angle is termed cubitus valgus; women have more valgus
6
Q
Elbow Complex: Joint Stability
A
joint capsule, ligaments, and close packed position
7
Q
Elbow Complex- Ligaments
A
ulnar collateral ligament (MCL): resists valgus stress; radial collateral ligamen (LCL): resists varus stress
8
Q
Elbow Complex- closed pack position
A
humeroulnar joint is most stable when in full extension; humeroradial joint is most stable when in full flexion
9
Q
Elbow Complex: Osteokinematics
A
flexion and extension; normal range of motion 0-150 degrees
10
Q
Elbow Complex: Arthrokinematics-Flexion
A
Concave: ulna and radius roll and glide anteriorly
Convex: humerus rolls anteriorly and glides posteriorly
11
Q
Elbow Complex: Arthrokinematics- Extension
A
Concave: ulna and radius roll and glide posteriorly
Convex: humerus rolls posteriorly and glides anteriorly
12
Q
Elbow Complex: roll/glide rules
A
roll for convex is always the same for concave; radius and ulna are the concave portion; humerus is the convex portion
13
Q
Forearm Structure: Superior
A
proximal radioulnar joint; a pivot joint; articulation between ulnar radial notch, annular ligament, capitulum of humerus and radial head
14
Q
Forearm Structure: Inferior
A
distal radioulnar joint; pivot joint; articulation between ulnar notch of radius, head of ulna, and articular disc (TFCC)
15
Q
Forearm: Osteokinematics
A
longitudinal axis from center of radial head to center of ulnar head; pronation (0-80 degrees) and supination (0-90 degrees)
16
Q
Forearm: Pathologies
A
Compression injuries, distraction injuries, valgus and varus ligament injuries; lateral epicondylitis; medial epicondylitis
17
Q
Forearm: compression injuries
A
fall on an outstretched hand; can lead to radial head olecranon, or coronoid processes fracture; you could dislocate your capitate or fracture the end of your radius
18
Q
Forearm: Distraction Injuries
A
radial head may slip out of annular ligament with enough longitudinal force; small children are particularly susceptible due to the radial head not being fully developed; commonly caused when a child is unexpectedly pulled or lifted by the arm (NS not turning on)
19
Q
Forearm: Varus/Valgus Ligament Injuries
A
UCL and RCA in throwers may become overstretched or torn resulting in pain and laxity; UCL tears are much more common than RCL; RCL probably due to dislocation;
20
Q
Forearm: Lateral Epicondylitis
A
usually seen in racquet sports where increased demand is placed on wrist extensors; all of these originate in the lateral epicondylitis; leads to microscopic tears; can eventually lead to tendon tear
21
Q
Forearm: Medial Epicondylitis
A
often seen in tennis serve and golf swing when the elbow is extended and the pronator theres, flexor carpi radialis and flexor carpi ulnas are active; not as common as lateral; much stronger than extensors
22
Q
Wrist Joint: Function
A
controls the multi-articular muscles of the wrist and hand; fine adjustment of grip; often open chain movements; the most complex joint of the human body
23
Q
Wrist or Carpus: Structure
A
includes radoiocarpal and mid carpal joints;
24
Q
Wrist Structure: degrees of freedom
A
2 degrees of freedom; radial and ulnar deviation and flexion/extension
25
Wrist: Radiocarpal Joint
Proximally- radius and radioulnar disk; distally- scaphoid, lunate, and triquetrum; TFCC acts to cushion compressive loads on the wrist
26
TFCC
Triangular fibrocartilaginous complex
27
Wrist: Midcarpal Joints
proximally: scaphoid, lunate triquetrum; distally: trapezium, trapezoid, capitate, hamate
28
Wrist: Intercarpal Joints
scaphoid to lunate; a gliding or planar joint; articulations between carpal bones; proximal row is more mobile than the distal row
29
Wrist: Ligamentous Support
responsible for providing articular stability and guiding and checking motion; extrinsic ligaments connect radius or ulna to metacarpals; intrinsic ligaments connect carpals to carpals
30
Wrist: Arches of the Wrist and Hand
Proximal transverse arch (runs over distal carpal row), distal transverse arch (metacarpal arch), and longitudinal arch (connects the two transverse arches)
31
Wrist and Hand: Osteokinematics
Sagittal plane motion (mediolateral axis)- flexion and extension; frontal plane (anteroposterior axis)- radial/ulnar deviation
32
Wrist and Hand: Arthrokinematics: radius and radioulnar disk
concave; flexion-anterior roll and glide; extension-posterior roll and glide; ulnar deviation- medial roll and glide; radial deviation- lateral roll and glide
33
Wrist and Hand: arthrokinematics: proximal carpal row
convex side; flexion- anterior roll posterior glide; extension-posterior roll anterior glide; ulnar deviation- medial roll, lateral glide; radial deviation- lateral roll, medial glide
34
Finger Structure
Finger rays; one ray includes one metacarpal and three phalanges (two in the thumb); numbered from radial side to ulnar side (1-5)
35
Fingers: Joints
carpometacarpal joints (between distal carpal row and metacarpals); metacarpophalangeal joints (articulation between metacarpals and phalanges); and interphalangeal joints (articulations between adjacent phalanges)
36
Fingers: Thumb Structure
CMC joint: forms a saddle joint between the first metacarpal base and the trapezium; allows for a wide range of motion; the most important motion of the thumb is opposition
37
Opposition
allows for the thumb to touch the tip of each finger
38
Wrist and Hand: Muscular Activity of the Wrist
flexor carpi ulnaris- the most powerful motor of the wrist and hand; places the hand in flexion and in ulnar deviation; the pisiform increases power by increasing the lever arm; flexors are greater than twice as strong as the extensors
39
Wrist and Hand: Muscular Activity of the Hand
extrinsic muscles are responsible for placing and changing the shape of the working hand; intrinsic muscles are responsible for maintaining the configuration of the three arches in the hand
40
Wrist and Hand: Power Grip
all three finger joints are held in a flexed position and the wrist is slightly extended to tighten the wrist flexor tendons; includes the cylindrical, spherical, and hook grips
41
Wrist and Hand: Precision Grip
involves the use of the thumb and fingers to manipulate a small object in a controlled manner; includes the pad to pad, tip to tip, and pad to side grips
42
Wrist and Hand: Pathologies
carpal tunnel syndrome, ligament sprains, colles' fracture, deQuervain's tenosynovitis, scaphoid or lunate fracture, osteoarthritis of the thumb
43
Carpal Tunnel Syndrome
where median nerve runs through to the hand; can show atrophy in the phenar eminence and intrinsic muscles; more common in women; rarely affects young people; most often compression in the carpal tunnel; may be due to vascular insuficiency
44
Ligament Sprains
usually due to a fall on an outstretched hand; may lead to chronic wrist pain if left untreated; lunate/capitate and radiocarpal ligaments are most commonly involved
45
Colles' Fracture
refers to an extra-articular fracture of the distal radius; may also include fracture of the ulna; one of the most common fractures; commonly affects older people and are more common in women due to osteoporosis
46
DeQuervain's Tenosynovitis
relatively common; inflammation and swelling of the tendon sheath covering the abductor pollicis longus and extensor pollicis longus; results in pain and limited thumb/wrist rang of motion
47
Scaphoid Fracture/Lunate Dislocation
Fall on an outstretched hand in a younger person; scaphoid may fracture on impact or the radius may cause the lunate to dislocate towards the palm; at risk for avascular necrosis;
48
Osteoarthritis of the Thumb
more common in women; typically bilateral but can be unilateral with trauma or overuse; erosion of the CMC saddle joint leads to pain and subluxation; ultimately strength and function are diminished
49
Shoulder Complex: components
shoulder girdle (scapula, clavicle, proximal humerus, AC joint); glenohumeral joint (glenoid fossa of scapula and proximal humerus)
50
Shoulder Complex: functions
shoulder girdle provides stability and mobility but also has very active muscles and neural activation to control and stabilize; glenohumeral joint positions upper extremity
51
Shoulder Girdle Articulations
scapulothoracic, sternoclavicular, and acromioclavicular joint
52
Scapulothoracic Joint
shoulder blade on thoracic cage; snapping scapula syndrome can cause the scapula to bump over the ribs; premier example of dynamic stability in the human body; almost 19 muscles have attachments to the scapula
53
Sternoclavicular Joint
a modified ball and socket; larger ROM
54
Acromioclavicular joint
acromion of the scapula to the clavicle; AC joint separation is common
55
Shoulder Complex- Scapulothoracic Joint- Kinematics
no joint or capsule or cartilage; elevation/depression, upward/downward rotation; anterior/posterior tipping; protraction/retraction
56
Glenohumeral Joint
articulation between glenoid fossa and humeral head covered in hyaline cartilage; glenodi fossa is shallow and can contain only 1/3 of the diameter of the humeral head;
57
Shoulder Complex- Glenohumeral Joint- Stability
provided by articular cartilage, glenoid labrum, capsule, and musculature
58
Shoulder Complex- glenoid labrum
fibrocartilaginous rim that serves to increase stability (provides 50% of overall glenohumeral depth)
59
Shoulder Capsule: Glenohumeral joint capsule
provides a stabilizing role and tightens with various arm positions; twice the size of the humeral head; frozen shoulder is a shrinking of this capsule that, in a specific pattern, limits various directions of motion
60
Shoulder Complex: Coraco-Acromial Arch
covers the humeral head and creates a space for the subacromial bursa; supraspinatus tendon and biceps brachii long head tendon; protects underlying structures from trauma; major site of dysfunction in the upper extremity
61
Shoulder Complex: subacromial pain syndrome
we all have some kind of impingement in this space, but only some have pain
62
Shoulder Complex: arthrokinematics
how the humerus (convex) moves on the glenoid (concave); mostly in an open-chain movement
63
Shoulder Complex: arthrokinematics of movemnets
flexion- superior roll and postero-inferior glide; external rotation- posterior roll and anterior glide; internal flexion- anterior roll and posterior glide
64
Shoulder Complex: scapulohumeral Rhythm
scapula, humerus, and clavicle moving to achieve full arm elevation; 180 degrees total motion is normal; 120 from glenohumeral and 60 from the scapulothoracic joint
65
Shoulder Complex: arm elevation- 0-30 degrees
primarily glenohumeral; supraspinatus and deltoid
66
Shoulder Complex: arm elevation- 30-180 degrees
scapulothoracic and glenohumeral movement at a 2:1 ratio (upper rotation); upper and lower trapezius along with serratus anterior
67
Shoulder Complex: pathologies
sub-acromial pain syndrome; adhesive capsulitis; shoulder instability;
68
Sub-Acromial Pain Syndrome
superior translation of the humeral head into the subacromial space; most common form of shoulder pain; probably more complex than that; can lead to bursitis, rotator cuff tear, biceps long head tear
69
Adhesive Capsulitis
frozen shoulder; capsular tightening of unknown etiology; more common in women and middle-aged elderly individuals; can be hormonal; maybe a progression of rotator cuff inflammation that spreads to the joint capsule; ROM is continually lost and pain increases
70
Adhesive Capsulitis: 3 stages
freezing (cortisone can be helpful; gradually loses ROM; pain); frozen (no pain but frozen); and thawing (regaining ROM)
71
Shoulder Complex: shoulder instability
dislocation is losing 100% of contact between the humeral head and the glenoid fossa; anything less is subluxation
72
Shoulder Complex:Labral Tear
can occur due to subluxing or dislocation; tearing the labrum of the glenoid
73
Traumatic Dislocation
only 15% success rate with conservative therapy; related to a specific injury; usually unidirectional and unilateral
74
Atraumatic Dislocation
no injury but very lax shoulders (with symptoms) usually bilateral and multidirectional (85% success rate with conservative therapy); usually genetic
75
Extensibility
muscle's ability to be stretched or to increase in length
76
Elasticity
ability to return to normal resting length following a stretch
77
Parallel Elastic Component
passive elasticity derived from muscle membranes
78
Series Elastic Component
passive elasticity derived from tendons when a tensed muscle is stretched
79
Stretch/Shortening cyclee
eccentric contraction followed immediately by concentric contraction; eccentric contraction leads to storing energy which adds to concentric contraction; muscle acts like a spring; good for power
80
Irritability
muscle's ability to respond to a stimulus
81
Muscle Fiber
a single muscle cell surrounded by a membrane called the sarcolemma and containing specialized cytoplasm called cytoplasm
82
Structural Organization of Skeletal Muscle
sarcomere (the basic structural unit of the muscle; the alternating dark and light bands give muscle is striations); motor unit (single motor neuron and all fibers it innervates)
83
Fast Twitch Muscle Fiber
reach peak tension and relax more quickly than slow twitch fibers; have greater tension
84
Slow Twitch Muscle Fiber
peak tension is typically slower and less forceful than fast twitch
85
Parallel Fiber Arrangement
fibers are roughly parallel to the longitudinal axis of the muscle; biceps brachii, sartorius;
86
Pennate Fiber Arrangement
short fibers attach to one or more tendons with the muscles; gastrocnemius; angle of pennation increases as tension progressively increses
87
Motor Unit Recruitment Order
slow twitch fibers are easier to activate than fast twitch fibers; increasing speed, force, or duration of movement involves progressive recruitment of MUs with higher activation thresholds
88
Concentric Movement
involves shortening of muscle; against what gravity is tending to cause
89
Eccentric Movement
involves lengthening of muscle
90
Isometric Movement
involving no change in movement;
91
Stabilizers
act to stabilize a body part against some other force
92
Neutraliers
act to eliminate an unwanted action produced by an agonist; example-prevents biceps from supinating arm during hammer curl
93
Active Insufficiency
failure to produce force when slack; decreased ability to form a fist when in wrist flxion
94
Passive Insufficiency
restriction of joint range of motion when fully stretched; fingers and elbow need to be flexed to find true ROM of wrist
95
Force-Velocity Relationship
when resistance (force) is negligible, muscle contracts with maximal velocity; velocity decreases as force goes up; there is an isometric maximum where velocity is 0
96
Length-Tension Relationship
tension present in a stretched muscle is the sum of the active tension provided by the muscle fibers and the passive tension provided by the tendons and membranes; when muscle length is short, there is no force or contraction that can occur; force is maximal when sarcomere is the perfect length to allow all of the myosin to pull on actin
97
Electromechanical Delay
time between arrival of a neural stimulus and tension development by the muscle (30-100ms)
98
Muscular Strength
the amount of torque a muscle group can generate at a joint; torque is the force that has a tendency to rotate an object
99
Factors Influencing Muscular Strength
Tension (cross sectional area and neuromuscular efficiency) and moment arms of the muscles crossing the joint (distance between muscle attachment and joint center; angle of the muscle's attachment)
100
Muscular Power
the product of muscular force and the velocity of muscle shortening; the rate of torque production
101
Muscular Endurance
the ability of muscle to exert tension over a period of time;
102
Muscle Temperature
the warmer a muscle is, the faster the speeds of nerves and muscle function
103
Strain
injury to muscle; deformation of tissue; combination of stretch and load; usually during eccentric contractions; "popping sarcomere" when sarcomeres can become weaker and tear;
104
Tendinopathy-Symptoms
injury to a tendon; mechanism is not clearly understood; repetitive strain can lead to tendon degeneration; both mechanical and material properties change;
105
Tendinopathy- Treatment
METH- movement, elevation, traction heat; or RICE- rest, ice, compression, and elevation; isometric contractions and eccentric contraction can induce hypoalgesia and desensitize the tendons to pain
106
Skeletal System: Function
protection, support, link and levers, and is a site for muscle attachments
107
Bone Stiffness
stress/strain in a loaded material; stress divided by the relative amount of change in shape
108
Bone Compressive Strength
ability to resist compression;
109
What contributes to stiffness and compressive strength?
Calcium carbonate and calcium phosphate; smoking and caffeine can leech phosphorus
110
What affects bone strength?
bone porosity, bone structure,
111
Bone Porosity
the amount of bone volume filled with pores or cavities; the less the pores, the stiffer the bone, thus can withstand greater stress but less strain; with more porosity, the bone can withstand less stress but greater strain
112
Bone Structure
bone is anisotropic; it has different strength and stiffness depending on the direction of the load; bone is strongest in resisting compression, ok at resisting tension, weakest in resisting shear force
113
Cortical Bone
compact mineralized bone with low porosity; found in the shafts of long bones
114
Trabecular or Cancellous Bone
less compact bone with high porosity; found in the ends of long bones and the vertebrae; allows for the ends of bones to not give in to gravity
115
Axial Skeleton
skull, vertebrae, sternum, ribs
116
Appendicular Skeleton
bones composing the body appendages
117
Short Bones
approximately cubical; include the carpals and tarsals
118
Flat Bones
protect organs and provide surfaces for muscle attachments; include the scapulae, sternum, ribs, patellae, and some bones of the skull
119
Irregular Bones
have different shapes to serve different functions; include vertebrae, sacrum, coccyx, and maxilla
120
Long Bones
from the framework of the appendicular skeleton; include the humerus, radius, ulna, femur, tibia, fibula
121
How do bones respond to training?
the densities, the sizes, and the shapes of bones are determined by the magnitude and direction of the acting forces (SAID principle)
122
Wolff's Law
osteoblasts and osteoclasts are continually building and resorbing bone; increased or decreased mechanical stress leads to a predominance of osteoblast or osteoclast activity respectively; weight bearing programs promote bone density
123
What tends to diminish bone density?
lack of weight bearing exercise; spending time in the water; bed rest; traveling in space; cycling
124
Osteoporosis-general
disorder involving decreased bone mass and strength with pain and one or more fractures resulting from daily activity;
125
Osteoporosis- type I
postmenopausal; osteoporosis affects about 40% of women after age 50
126
Osteoporosis- type II
age-associated; osteoporosis affects most women and men after age 70
127
Osteoporosis-Treatment
postmenopausal hormone replacement; dietary calcium and vitamin D; avoid smoking, caffeine, and alcohol
128
Geenstick Fracture
one side of bone is broken, the other side is bent (in children)
129
Comminuted Fracture
broken into 3 or more pieces (shattered)
130
Stress Fracture
tiny cracks in the bone due to repetitive application of force
131
Fatigue Fractures
normal bone subject to repeated forces and does not have time to repair
132
Insufficiency Fractures
a weak bone (osteoporosis) fails under routine activity
133
Risk Factors for stress fractures
high impact sports, poor dynamic shock absorption, sudden shift from inactivity to frequent exercise, females with amenrorhea
134
Stress Fracture Prevention
start exercise programs gradually, avoid prolonged activity, avoid sudden changes in type of exercise or intensity; train to improve shock absorption/decrease ground reaction force; cross-training; use proper equipment
135
Osgood Schlatter Disease
overuse condition that develops in adolescents due to repetitive tension of patellar tendon on the immature tibial tuberosity;
136
Osgood Schlatter Disease- treatment
rest from high-load quad activities; stretchingof quadriceps and adequate warmup/cool down
