Kinesiology Exam 1

Analysis of forces acting on the neuromusculoskeletal system

Study of motion by position, velocity, and acceleration

Study of the effects of forces

Magnitude, direction, point of application

Mechanical interaction of an object and its surroundings

Perpendicular to the component

Parallel to the component

An object in motion will remain in motion unless a force acts upon it (inertia)

The larger the mass, the more force needed to accelerate the object (acceleration); F=ma

For every force, there is a force opposing it in the opposite direction with the same magnitude (FA=-FB)

GRF, EFm, Fc, RJF

Gravity/weight

Vertical, forwardack (A/P), side to side (M/L)

A/P and M/L GRF components

EFm and Fc

Points towards the joint

Points away from the origin or insertion site

Point of force application of body mass on the system; usually concentrated; can change position with motion

Concentrated GRF point

A force applied to an object that creates angular motion about an axis

Perpendicular distance between axis of rotation and line of action of the force

Increase torque

Decrease torque

EFR; =1, >1, or <1

Head and neck stabilization

Calves

FRE; >1

FER; <1

Biceps (most common lever in the body)

Two forces equal in magnitude and opposite in directions that cause pure rotation

Hip flexors and erector spinae

Hip extensors and abdominals

Linear; EF=0

Angular; EMo=0

Segment is not moving; EML=RJT

Segment is shortening and moving in the same direction as RJT; EML<RJT

Segment is lengthening and moving in the opposite direction as RJT; EML>RJT

Distal segment is moving; proximal segment is fixed

Proximal segment is moving; distal segment is fixed

GRF compresses joint (good for hypermobility and bad for osteoarthritis); co-contraction causes increased stability at joint; increases somatosensory and proprioceptive input; more functional position for LE; CAN'T isolate specific joints which can allow for compensation

Velocity is in the same direction as acceleration

Velocity is in the opposite direction as acceleration

Natural sequence of movement; cause to effect

Effect to cause

The motion of bone relative to the three cardinal planes of the body

The motion of the articular surfaces of the joint

Shape of joint surfaces

Multiple points along one articular surface contact multiple points on another articular surface

A single point on one articular surface contacts multiple points on another articular surface

A single point on one articular surface rotates on a single point on another articular surface

Roll and glide often occur together

Roll and glide in OPPOSITE directions

Roll and glide in SAME direction

ANTERIOR roll; POSTERIOR glide

ANTERIOR roll; ANTERIOR glide

SUPERIOR roll; INFERIOR glide

Spinning of radius on capitulum

The muscle whose action is to produce the desired motion

The muscle whose action is to oppose the agonist

When both the agonist and the antagonist contract simultaneously (stabilizes the joint)

A muscle whose action is to assist the prime mover to perform the desired motion by either directly performing the task, canceling out unwanted torques, or stabilizing proximal segments

Refers to agonist; when a muscle cannot shorten anymore; LT curve

Refers to antagonist; when a muscle cannot lengthen anymore

Relative displacement of any two points within the object

Stretching (muscle contraction)

Weight bearing joints; soft tissues during sitting

Combination of tension and shear; falling

Force parallel to a surface; skin, joint surfaces, ligaments

Twisting force

Combination of two or more types of loading

The steeper the curve, the harder it is to pull

Force/Area

Intensity of forces acting in the plane PERPENDICULAR to a cross-section of material (tensile or compressive)

Intensity of forces acting in the plane PARALLEL to a cross-section of material

Degree of deformation associated with axial forces (tensile or compressive)

Degree of deformation associated with shear forces

Change in length/original length

Elastic, plastic, or viscoelastic

Describe the way a material responds to imposed forces

Ability of a material to resume its original size and shape upon removal of applied loads

If stress-strain curve is a straight line

Young's modulus (E=stress/strain)

Inability of a material to resume its original size and shape upon removal of applied loads

Delineates elastic and plastic zones on stress-strain curve

Stress corresponding to yield point

Start length does not equal end length