BIOMECH 1 USE

3rd lever

MA<1 (force in the middle)

2nd lever

MA>1 (resistance in the middle)

1st lever

MA>1, <1, =1 (fulcrum in the middle)

Draw the force-length relationship

Draw stress-strain curve

Resistor (body)

body and environment

Machine (body)

bones and joints

Motors

skeletal muscle

Ball & Socket

3 DOF, acetabulofemoral

Saddle

2 DOF, Carpal metacarpal

Condyloid

2 DOF, radiocarpalis

Pivot

1 DOF, Proximal/distal radioulnar

Hinge

1 DOF, Humeroulna

Gliding

0 DOF, intercarpals

Electromechanincal delay (EMD), the time gap between the arrival of neural stimulus (or onset of muscle contraction) and the actual tension development by the muscle, is caused by ___ of the musculotendinous unit.

The series elastic component (SEC)

Which of the following statements about muscular power is incorrect?

Individuals with predominance of slow-twitch (ST) fibers (motor units) generate more power at a given load than individuals with high percentage of fast-twitch (FT) composition since ST fibers are characterized by slower but higher maximal tension

______ compose the contractile component (CC) of the muscle model.

Actin and Myosin filaments

Which of the following statements about the moment arm is incorrect?

Moment arm of a muscle becomes minimum when its angle of pull is 90 degrees

In human-machine systems, _____________ as motors

skeletal muscle

Over 95% of the joints found in the human body form _________, which are characterized by disadvantage in force but advantage in motion (displacement or velocity)

3rd class levers

In slow flexion/extension of the elbow in the arm curl exercise, with a dumbbell on the hand, _______ are the agonists

elbow flexors

Which of the following is not a component of Hill's muscle model?

Series of viscous component

Which of the following is not a basic property of the musculotendinous unit?

Repeatability

According to the force-length relationship of the skeletal muscle, the maximum amount of active tension (force) is produced at its ___

resting length (or optimal length/resting sarcomere length)

The ___________, the number of muscle fibers controlled by a single motor neuron in a motor unit, is a function of the functional role of the muscle (fine motor control vs. gross motor control)

innervation ratio

Which of the following muscle fiber types is the most resistant to fatigue?

slow-twitch and oxidative (SO)

Muscle activation involving lengthening of the muscle is _____________

eccentric contraction

According to the force velocity relationship of the skeletal muscle, a muscle can produce ________ active tension under eccentric contraction than under concentric contraction

a larger

___________, which can be found in the knee joint, is a form of articular fibrocartilage functions to distribute the loads over t surfaces to improve the fit of the articular surfaces to limit slip of one bone with another.

Meniscus

The angle through which a joint moves from the neutral position to the extreme limit of segment motion in a particular direction is called the __________. Joint flexibility is assessed by this allowed in each of the planes of motion at a joint.

range of motion

Which of the following is not a contributing factor to the knee stability?

Synovial fluid in the joint capsule

Which of the following is NOT a common cause of injury?

Excessively high activity of osteoblasts.

The best way to improve joint stability is ________ the connective tissue. while the best way to improve joint flexibility is ________ of the connective tissue.

strengthening , stretching

Which of the following statements about joint stability is incorrect? Joint stability is the opposite term of joint flexibility.

As joint stability increases as a result of training, joint flexibility always decreases.

The main mechanical function of the tendon sheaths and bursae, the anatomical structures commonly associated with synovial joints, is ______________.

lubrication and reduction of friction

The tibiofemoral joint is a ___________.

hinge joint

Which of the following is not a typical element of a synovial joint?

Fibrocartilaginous disk

Which of the following synovial joints provides the largest number of degrees of freedom?

Ball and socket joints

The proximal and distal radioulnar joints are ________.

pivot joints

The order of motor unit recruitment during activity is _________

1 > 2a > 2b

How do bones typically respond to exercise?

Hypertrophy

______ bone protects the underlying organs and soft tissues and also provides large areas for muscle and ligament attachments.

Flat

Which of the following statements about the bone is correct?

Bone grows when it is needed and is reabsorbed when it is not needed.

______ is a protein which provides bone with flexibility and contributes to its tensile strength.

Collagen

For a given force, a decrease in the cross sectional area would produce an __________ stress.

increase in mechanical

Pronation/Supination of the forearm occurs about the _________ axis of the forearm.

longitudinal

Which of the following is NOT an important property of force?

Plane of application

__________ is the distribution of force inside a solid body.

Mechanical stress

__________ is the pulling or stretching force directed axially through a body.

Tension

____________ are the directional terms used specifically for the limb segments, meaning "Closer to" or "away from" the trunk.

Proximal/distal

____________ is (are) the joint motions in the frontal plane.

Abduction/adduction

________ causes motion and is the primary quantity of interest in kinetics.

Force

The area of study in biomechanics that deals with description of motion is __________.

Kinematics