• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/61

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

61 Cards in this Set

  • Front
  • Back
Kinetics
focuses on the amount and type of movement, the direction of movement and speed or change of speed of the object
kinematics
Study that examines the forces acting on a system such as the human body; an attempt to define the forces that cause a movement
First Class lever
• When two forces are applied on either side of an axis at some distance from that axis, creating rotation in opposite directions.
• First class levers rarely occur in human body because point of application of muscle must be on the opposite side of joint axis from external force.

• Effort Arm: lever arm of the effort force.
• Resistance Arm: lever arm of the resistance force.
• Triceps extending the elbow; supraspinatus; the seesaw
2nd class lever
o When two resultant forces are applied so that the resistance lies between the effort force and the axis of rotation.
o Effort arm is always larger than resistance arm
-Gastrocnemius & Soleus acting to create PF; the wheelbarrow
3rd class lever
o When forces are applied so that the effort force lies closer to the axis than does the resistance.
o Effort Arm will always be smaller than Resistance Arm.
o A muscle creating joint rotation of its distal segment in the direction of its pull is most often part of a third class lever system.
Lever example
Biceps Brachii acting radius to create elbow flexion; the shovel.
*Because the effort force is directed very close to the axis, it allows for the large range of motion.
*With eccentric contraction, the EF and R forces are reversed. You would then have a very short resistance arm (created by biceps) and a very long effort arm (radius and ulna) and this is a 2nd class lever.
When a muscle is contracting eccentrically (actively lengthening)
the muscle must be acting in a direction opposite to the motion of the segment; that is, the muscle must be the resistance force (RF).
o Mechanical Advantage
o A measure of the efficiency of the lever and is related to the class of lever and used to develop an understanding of the relevance of the concept of classes of levers.
-M Ad = EA/RA
2nd class lever MA
o The magnitude of the effort force can be smaller than the magnitude of the resistance.
• This means that a small effort force can create more torque and overcome a larger resistance.
o When EA is greater than RA, i.e.. When M Ad is greater than one, the EF can be smaller than Resistance (R) and still create more force.
o The “advantage” to lever with a mechanical advantage greater than one is simply that the effort force can overcome the resistance without expending as much force as the resistance.
3rd class lever MA
, EA is always smaller than RA since the effort force lies closer to the axis than the resistance
o Tradeoff is (increased ROM); ie. Biceps at elbow joint
o M Ad of the third class lever will always be less than one.
o Inefficient in that the magnitude of the effort required to move the lever will have to be greater than the magnitude of the resistance.
Moment Arm
o The shortest distance between the action line and the joint axis and is found by measuring the length of a line drawn perpendicular to the force vector, intersecting the joint axis.
Agonist
- muscle that causes specific movement or possibly several movements to occur through the process of its own contraction. This is typically a term designated for skeletal muscles. Agonists are also referred to, interchangeably, as "prime movers", since they are the muscles being considered that are primarily
Antagonist
- acts in opposition to the specific movement generated by the agonist and is responsible for returning a limb to its initial position
Synergist
helps perform the same set of joint motion as the agonist
Neutralizers
help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion.
Stabilizer
a muscle acting on a segment to allow motion at an adjacent joint to occur
Open Chain
• When the ends of limbs or parts of the body are free to move without causing motion at another joint.
• Motion does not occur in a predictable pattern.
• Distal end of extremity free in space.
• Distal end of extremity not in contact with fixed object.
• Movement pattern is characterized by rotary stress in joint.
• Joint movements occur in isolation.
• Muscle recruitment and movements are isolated.
• Joint axis stable during movement.
• Proximal portion of joint stable – distal segment mobile.
• Movement pattern often non functional
• Movement causes shear forces in joint.
Closed chain
• Occurs when the ends of limbs meet a fixed resistance such as in weight bearing, i.e., the squat.
• Motion will occur in a predictable pattern.
• Distal end of segment fixed to something.
• Movement pattern is characterized by linear stress in joint.
• Multiple joint movements occur simultaneously.
• Both segments move together.
• Co-contraction of muscle around joint.
• Movement is not inhibited.
• Moving more than one joint
• OKC – “inhibited” in that only one joint is moving
• Loading is physiological and more functional.
• Movement causes compression, thus enhancing stability.
Skeletal muscles surrounded by? Which contain?
-epimysium
-muscle fascicles
Muscle fascicles surrounded by? which contain?
-perimysium
-muscle fibers
Muscle fibers surrounded by? which contain?
-endomysium
-myofibrils
Myofibrils composed of? which contain?
-sarcomeres
- dark thick myosin and light thin actin
Long bones
• Longer than they are wide
• Have shaft and diaphysis
• Shaft widens at end to form metaphysis
• End of bone is epiphysis
• End of bone consists of thin outer layer of compact bone covering spongy bone
• Periosteum is thin membrane covering bone
• Support body and create levers
• Length formed by compressive forces
• Protuberances formed by tensile forces
Short bones
o Consist of primarily spongy bone covered with thin layer of compact bone
o Play an important role in shock absorption and transmission of forces
o Forces are dissipated among all the bones (larger surface area with more bony contact)
Flat bones
• Represented by ribs, scapula, ilium and sternum
• Two layers of compact bone, with spongy bone and marrow in between
• Protect internal organs and offer surfaces for muscular attachment
Irregular bones
• Skull, pelvis and vertebrae
• Consist of spongy bone with a thin compact bone exterior
• Functions include weight bearing, dissipating loads. Protecting spinal cord, site for muscle attachments
Sesmoid bones
• Short bone embedded within a tendon or joint capsule
• Found in the quadriceps, base of first metatarsal in flexor hallucis brevis, thumb in the flexor pollicus brevis
• increase the moment arm of the given tendon = more powerful
fusiform muscle
fibers run parallel along the muscle’s length;
physiologic and anatomic cross-sectional areas are equal;
high amounts of shortening; high velocity movements;
longer than most muscles; fiber length greater than tendon length;
i.e. sternocleidomastoid, rectus abdominis, biceps brachii
pennate muscle
fibers run diagonally with respect to the muscle’s longitudinal axis;
physiologic cross-sectional area is greater than the anatomic cross-sectional area;
fibers shorter and more numerous fusiform muscle fibers; slower movement velocities;
produce greater maximal force than fusiform muscles of similar volume;
i.e. semimembranosus (unipennate), gastrocnemius (bipennate), deltoid (multipennate)
irritability
– the ability of a muscle to respond to stimulation; muscle is stimulated by chemical neurotransmitters; only nerve tissue is more sensitive than muscle tissue
contractibility
ability to shorten when sufficient stimulation is received; muscle shortens as much as 50-70% of resting length; average shortening length is 57% of the muscle’s resting length
extensibility
ability to lengthen out or stretch beyond resting length; this is determined by the connective tissue found in the perimysium, epimysium, and fascia surrounding a muscle
elasticity
– ability to return to resting position once stretch is removed; determined by a muscle’s connective tissue rather than its muscle fibers; protective mechanisms exist within a muscle to maintain its integrity and length; muscle will always return to its original length unless torn
Roll
• Refers to the rolling of one joint surface on another, as in a tire rolling on the road.
• In the knee the femoral condyles roll on the fixed tibia.
Slide
• A pure translatory motion, which refers to the gliding of one component over other.
• Like wheels sliding on ice.
• In the shoulder the humerus slides inferior during abduction.
Spin
• A pure rotary motion.
• The rotation of a movable component.
• At the elbow, the head of the radius spins on the capitulum of the humerus during supination or pronation.
Ovoid
one surface convex and one concave
Sellar
each surface has both convex and concave
Convex on concave
– roll and glide are in opposite directions
Concave on convex
roll and glide are in same directions
Finger flexor/finger extensors
Extending the wrist causes the fingers to flex due to passive insufficiency. In the hand this is called tenodesis.
Concurrent force system
i. Two or more forces acting at a common point of application but in divergent directions.
ii. Quite common in the human body.
iii. The net effect, or resultant, off concurrent forces appears to occur at the common point of application
Composition force
i. R is not equal to the sum of the magnitudes of AB and BB.
ii. The block would be pulled more efficiently if a single force is applied in the direction of R.
iii.
iv. PcLf and AcLf are a concurrent force system.
v. CLf must be equal in magnitude and opposite in direction to the sum of Gravity on leg and foot
Axial
- head, neck, trunk (ribs)
Appendicular portion
i. Humerus
ii. Radius and Ulna
iii. Carpals, Metacarpals and Phalanges
iv. Movements of the arm
v. Forearm movements
vi. Hand movements
vii. Thigh
viii. Leg
ix. Foot
x. Movement of Thigh
xi. Leg movements
xii. Foot movements
Suture joint
): a joint in which two bony components are united by a thin layer of dense fibrous tissue.
a. Edges generally interlock or overlap one another
b. Initially these joints are mobile.
c. Later in life lead to bony union called “synostosis” (no movement)
Gomphosis joint
(tooth): a joint in which the surfaces of bony components are adapted to each other like a peg in a hole.
a. A tooth – between mandible and maxilla.
Syndesmosis joint
(between Tibia and Fibula) (between Ulna and Radius): a type of fibrous joint in which two bony components are joined directly by a ligament, a fibrous cord or aponeurotic membrane.
a. Tri-malleolar fracture or severe ankle sprain can cause separation of tibia and fibula.
b. May require surgery to stabilize
Symphysis Joint
(Pubic Symphysis) : the two bony segments are covered by thin lamina of hyaline cartilage and directly joined by fibrocartilage in the form of disks or plates.
a. Allow limited to moderate amounts of movement
b. Intervertebral joints.
c. Manubrium and sternum.
d. Symphasis pubis in pelvis.
e. *Generally exist near the midline of the body
Sychondrosis
(primary cartilaginous joint) a type of joint in which the material used for connecting the two components is hyaline growth cartilage.
a. Permits growth while also providing stability and small amount of mobility
b. When bone growth is complete, some of these joints ossify and convert to bony unions (synostoses).
Condyloid Joint
a. Joint shaped so that the concave surface of one bony component is allowed to slide over the convex surface of another component in two directions.
b. MCP joint of fingers
c. Femoral Tibia
Saddle Joint
a. Joint in which each joint surface is both convex in one plane and concave in another.
b. Fit like a rider on a saddle.
c. CMC joint of thumb, sternoclavicular joint
Trochoid Joint
2. Pivot (Trochoid) Joint
a. Constructed so that one component is shaped like a ring and the other component is shaped so that it can rotate within the ring.
b. AA joint, radiohumeral joint
c. Pronation and Supination
Plane joints
a. Permit gliding between two or more bones.
b. Carpal joints.
c. Adjacent surfaces may glide or rotate with regard to one another in any plane.
Ball and socket joints
a. Formed by a ball-like convex surface being fitted into a concave socket.
b. Hip and shoulder joints.
Supination of foot
: combined set of movements; ankle plantar flexion, tarsal inversion and forefoot adduction.
Pronation of foot
: combined set of movements; Dorsi-flexion at ankle, eversion at the tarsals, abduction of forefoot.
Ruffini endings
outer layer of joint capsule
Pacinian corpuscles
Outer layer of joint capsule
Golgi-Mazzoni corpuscle
Inner layer of joint capsule
free nerve endings
Throughout capsule and in ligaments