NESTA Biomechanics Specialist

In standard anatomical position, the body is described as standing upright with the feet together and the palms facing which direction?

• APosteriorly (backward)
• BSuperiorly (upward)
• CMedially (toward midline)
• DAnteriorly (forward)

The sagittal plane divides the body into which two parts?

• ARight and left
• BAnterior and posterior
• CSuperior and inferior
• DProximal and distal

Abduction and adduction of the limbs occur primarily in which plane of motion?

• ASagittal plane
• BOblique plane
• CTransverse plane
• DFrontal (coronal) plane

What is the key difference between kinematics and kinetics?

• AKinematics studies forces; kinetics describes motion without regard to forces
• BKinematics applies only to muscles; kinetics applies only to bones
• CThey are identical terms used interchangeably
• DKinematics describes motion (position, velocity, acceleration); kinetics studies the forc…

Which term describes a movement that decreases the angle at a joint, such as bending the elbow during a biceps curl?

• AExtension
• BPronation
• CAbduction
• DFlexion

Movement of a body segment toward the midline of the body in the frontal plane is called:

• AAbduction
• BRotation
• CCircumduction
• DAdduction

The transverse plane is associated with which axis of rotation?

• AMediolateral (frontal) axis
• BAnteroposterior axis
• CLongitudinal (vertical) axis
• DOblique axis

In anatomical directional terminology, the term 'distal' means:

• ACloser to the point of attachment or trunk
• BToward the midline
• CToward the front of the body
• DFarther from the point of attachment or trunk

A scalar quantity differs from a vector quantity in that a scalar:

• AHas both magnitude and direction
• BCan only be negative
• CAlways acts at a right angle to motion
• DHas magnitude only, with no direction

Which pair correctly distinguishes speed from velocity?

• ASpeed is a vector; velocity is a scalar
• BVelocity ignores time; speed includes time
• CThey are the same quantity measured in different units
• DSpeed is distance per unit time (scalar); velocity is displacement per unit time (vector)

Plantarflexion of the ankle, as occurs when rising onto the toes, takes place in which plane?

• AFrontal plane
• BTransverse plane
• CSagittal plane
• DScapular plane

The center of mass (center of gravity) of a standing adult in anatomical position is located approximately at the level of the:

• ASternum
• BBase of the skull
• CKnee joints
• DSecond sacral vertebra (anterior to S2), about 55% of standing height

Newton's first law (the law of inertia) states that an object will:

• AAccelerate in proportion to the net force applied
• BAlways return to its original position after deformation
• CExert a force equal and opposite to any force applied to it
• DRemain at rest or in uniform motion unless acted upon by a net external force

Newton's second law is most commonly expressed as which equation?

• AForce = mass × acceleration
• BForce = mass ÷ velocity
• CForce = work × time
• DForce = momentum × distance

Newton's third law states that for every action force there is an equal and opposite reaction force. During running, this is best illustrated by:

• AThe runner's muscles generating heat
• BGravity pulling the runner downward
• CAir resistance slowing the runner over time
• DThe ground pushing back on the foot with a force equal and opposite to the force the foot…

Torque (moment of force) about a joint is calculated as:

• AForce divided by the moment arm
• BForce multiplied by time
• CMass multiplied by acceleration
• DForce multiplied by the perpendicular distance from the axis to the line of force (moment…

A muscle generates 200 N of force acting at a perpendicular distance of 0.03 m from the joint axis. What torque does it produce?

• A6 N·m
• B60 N·m
• C0.15 N·m
• D6,667 N·m

In a first-class lever, the arrangement of components is:

• AEffort, then resistance, then fulcrum
• BEffort between the fulcrum and the resistance
• CResistance between the fulcrum and the effort
• DFulcrum located between the effort and the resistance

Most levers in the human body are third-class levers. A defining feature of a third-class lever is that the:

• AEffort is applied between the fulcrum and the resistance
• BResistance is always closer to the effort than to the fulcrum
• CFulcrum is always at the very end of the lever
• DMechanical advantage is always greater than 1

Rising onto the toes (standing calf raise) uses the foot as which class of lever, with the ball of the foot as the fulcrum and body weight as the resistance?

• AFirst-class lever
• BNot a lever system
• CThird-class lever
• DSecond-class lever

Mechanical advantage of a lever is defined as the ratio of the:

• AResistance arm to the effort arm
• BFulcrum length to the lever length
• CEffort force to the resistance force, regardless of arm length
• DEffort arm to the resistance arm

Which factor will INCREASE the stability of a standing client?

• ARaising the center of mass higher
• BNarrowing the base of support
• CWidening the base of support and lowering the center of mass
• DShifting the center of mass toward the edge of the base of support

An object is in static equilibrium when:

• AIt is accelerating uniformly
• BIts kinetic energy is maximized
• COnly the net torque is zero but net force is nonzero
• DThe sum of all forces and the sum of all torques acting on it are both zero

The 'line of gravity' is best described as:

• AA vertical line passing downward from the center of mass toward the ground
• BA horizontal line through the hips
• CThe path the body travels during a jump
• DThe boundary of the base of support

Inertia is most directly proportional to an object's:

• AVelocity
• BSurface area
• CAcceleration
• DMass

A barbell is balanced on a fulcrum. A 100 N load sits 0.4 m from the fulcrum on one side. To balance it, what force is needed 0.8 m from the fulcrum on the other side?

• A200 N
• B25 N
• C100 N
• D50 N

Which body lever example is most commonly classified as a third-class lever?

• AThe skull pivoting on the atlanto-occipital joint
• BA seesaw balancing two children
• CThe ankle during a heel raise
• DThe elbow during a dumbbell biceps curl (biceps as effort)

If the net external force acting on a body is zero, Newton's first law predicts the body will:

• ASpeed up gradually
• BSpiral toward its center of mass
• CReverse its direction of travel
• DMaintain constant velocity (including possibly remaining at rest)

Why do most human joints operate at a mechanical disadvantage (third-class levers)?

• ATo minimize the muscle force required for any task
• BTo reduce joint reaction forces to zero
• CBecause the body cannot generate large muscle forces
• DTo maximize the speed and range of motion of the distal segment

Angular motion (rotation) of a body segment occurs:

• AOnly when the segment moves in a straight line
• BExclusively during isometric contractions
• COnly in the absence of any torque
• DAround an axis of rotation, such as a limb rotating about a joint

The weight of an object is best described as:

• AThe amount of matter it contains, measured in kilograms
• BIts resistance to a change in motion
• CIdentical to its mass in all environments
• DThe gravitational force acting on its mass (mass × gravitational acceleration)

What is the approximate weight (gravitational force) of an 80 kg person on Earth (g ≈ 9.81 m/s²)?

• AAbout 80 N
• BAbout 9.81 N
• CAbout 8 N
• DAbout 785 N

Ground reaction force (GRF) is:

• AThe force the body's muscles produce internally
• BA purely horizontal braking force only
• CAlways exactly equal to body weight at all times during running
• DThe force the ground exerts back on the body in reaction to the force the body applies to…

The maximum static friction force between two surfaces is determined by the:

• ASurface area of contact only
• BVelocity of the moving object only
• CCoefficient of friction multiplied by the normal force
• DMass of the object divided by gravity

Linear momentum is calculated as:

• AMass × velocity
• BForce × distance
• CMass × acceleration
• DVelocity ÷ time

Impulse is defined as:

• AForce multiplied by the time over which it acts
• BMass divided by velocity
• CWork divided by power
• DForce divided by distance

Landing from a jump by flexing the hips, knees, and ankles ('soft' landing) reduces peak impact force primarily because it:

• AEliminates the ground reaction force entirely
• BIncreases the body's mass on contact
• CIncreases the time over which momentum is reduced, lowering the average force (impulse-mo…
• DRemoves the need for eccentric muscle action

Mechanical work is performed when:

• AA force acts on an object and causes displacement in the direction of the force
• BA muscle contracts isometrically with no joint movement
• CAn object remains perfectly still under load
• DTwo equal forces cancel each other

Power in mechanical terms is best defined as:

• AThe total force applied during a movement
• BThe product of mass and velocity
• CThe rate of doing work (work per unit time)
• DThe energy stored in a stretched tendon

A lifter raises a 60 kg barbell 0.5 m vertically. Approximately how much mechanical work is done against gravity (g ≈ 9.81 m/s²)?

• AAbout 30 J
• BAbout 120 J
• CAbout 294 J
• DAbout 1,177 J

Kinetic energy of a moving object depends on its:

• AMass and the square of its velocity
• BMass only
• CHeight above the ground only
• DSurface texture

Gravitational potential energy of a lifted object increases with:

• ADecreasing height
• BDecreasing mass only
• CIncreasing height above a reference point
• DIncreasing horizontal velocity

During the braking (early stance) phase of running, the horizontal ground reaction force typically acts:

• AForward, in the direction of travel
• BStraight downward only
• CBackward, opposing the runner's forward motion
• DStraight upward only

Why can a chalked grip help a lifter hold a heavier deadlift?

• AChalk reduces the normal force on the bar
• BChalk increases the bar's mass
• CChalk reduces moisture and increases the effective coefficient of friction between hand a…
• DChalk eliminates gravity acting on the bar

A force applied so that its line of action does NOT pass through an object's center of mass will tend to cause:

• APure linear translation only
• BNo motion at all
• CRotation (and possibly translation) of the object
• DAn increase in the object's mass

Why do vertical ground reaction forces during running commonly reach 2 to 3 times body weight?

• ABecause gravity increases during running
• BBecause muscles add mass to the body in flight
• CBecause the body must rapidly decelerate and reaccelerate its mass during each short grou…
• DBecause friction adds to the vertical force

The impulse-momentum theorem states that the impulse applied to an object equals its:

• AChange in momentum
• BChange in mass
• CTotal kinetic energy
• DCoefficient of friction

In a synovial joint, the structure that reduces friction by providing lubrication is the:

• APeriosteum
• BTendon sheath of the prime mover
• CSynovial fluid within the joint capsule
• DCortical bone surface