Movement Science - Exam 3 (final)

Speed (distance/time)

how fast you’re traveling

Velocity (m x s)

speed in a given direction (time rate of change of displacement)

Acceleration (final velocity - starting velocity/time)

time rate of change of velocity

Mass

quantity of matter composing an object (grams, pounds, ounces)

Momentum (mass x velocity)

quantity of motion an object possesses

(tendency of body to stay in motion)

Force (F = m x a)

form of energy that causes movement and has direction and magnitude

Base of support

area of contact btw the body and supporting surface

Increasing BOS will ____ the stability and balance of human body

increase

Center of gravity

the point in the body or an object around which its weight is balanced and equal on all sides

Moves as we move

Where is the COG in the human body

anterior to the 2nd sacral vertebra (L5 in men)

Line of gravity

imaginary line that runs through the center of gravity

must fall within the BOS for object to be stable

Balance is maintained when COG remains over or within

BOS

Linear motion

movement in a straight line

Angular motion

rotational movement through an arc

All joints in the body produce ______, but movement of entire body through space is _____

angular motion; linear

Newtons 1st law of motion (inertia)

body remains at a state of rest or remains in uniform motion until a force acts on it

Friction

force that resists the relative motion of two surfaces in contact

Newtons 2nd law of motion (acceleration)

acceleration of an object is directly proportional to the force causing motion and inversely proportional to the mass of the object being moved

F = m x a

Newtons 3rd law of motion (action-reaction)

for every action there is an equal and opposite reaction

Moment/lever arm

length btw a joint axis and the line of force acting on that joint

Torque

when a force causes rotational movement

Torque is the product of what two aspects of the moment arm

force and length

Line of pull (applied force)

long axis of the muscle

Angle of pull

angle btw the long axis of the bone (moment arm) and the line of pull

What angle of pull produces the greatest torque

90 deg

Increased angle of pull causes the ability to produce rotational force to

decrease

Muscle’s non-rotational force will do one of two things

stabilize the joint (compression)

destabilize the joint (distraction force)

1st class lever (Cervical Extension)

fulcrum is btw the force and resistance arms

Force - Axis - Resistance

Basics of a 1st class lever

balanced movement

axis close to resistance + force

convert downward force to upward force

2nd class lever (Calf Raises)

resistance lies btw the force and fulcrum

Axis - Resistance - Force

Basics of a 2nd class lever

move large resistance w/little force

load moves in same direction as force applied

small ROM

3rd class lever (Elbow Flexion)

force point is btw the resistance and fulcrum

Axis - Force - Resistance

Basics of 3rd class lever

produces speed

more movement distally than near force

increased ROM

Which of the three class levers is the MC in the body

3rd

Physiologic advantage of muscles

muscles ability to shorten

Optimal length of a muscle for maximal physiologic advantage is at its

full resting length

Active and passive insufficiency occur in

multi-joint muscles

Active insufficiency

inability of a bi-articular or multi-articulate muscle to exert adequate tension to SHORTEN enough to complete full ROM in both joints simultaneously

Passive insufficiency

inability of a bi-articular or multi-articulate muscle to STRETCH enough to complete full ROM in both joints simultaneously

Summation of forces

sequence of movements timed so that each movement contributes to the next movement to produce a desired outcome

Types of Energy (capacity to do work)

Potential energy - capacity to do work that is stored in a body

Kinetic energy - energy a body has because of its motion

When a body stops moving, kinetic energy is converted into

potential energy

Elasticity

ability of an object to resume its former shape after deforming or distorting force is applied then released

Elastic deformation

a material will be able to deform and return to its original shape repeatedly without permanent deformation

Plastic deformation

loading force causes permanent change in the structure of a material

Creep

when a low-level stress (starting in elastic range) is applied over a long enough period to cause plastic deformation

causes a realignment of tissue’s collagen, proteoglycans, and water = permanent change!

Stiffness

ability of an object to resist deformation when a stress is applied to it

Having the ability to decelerate and control one’s own body is crucial for

lowering risk of injury

Stress

force that changes the form/shape of a body

Strain

amount of change in the size/shape of object caused by stress

Shear force

unaligned forces acting on one part of a body in a specific direction, and another part of the body in the opposite direction

Torsional force

twisting of an object due to an applied force

Structural fatigue

point at which a tissue or object can no longer withstand a stress and breaks or fails

can occur in a sudden movement or over time with accumulation of stress

ALL tissues are subject to this

Average joint moves through

3 different planes of movement

sagittal (X), horizontal (Y), frontal (Z)

Paraphysiological space (end range joint play)

small ROM that can ONLY be obtained passively by the examiner

How do adjustments work

restoring motion to fixated, sticky joints

restoring normal function to the segmental level + surrounding tissues

Joint manipulation occurs outside a joint’s

physiologic ROM

Skin-fascia interface onto underlying bone is frictionless therefore, when performing an adjustment, it is optimal to place the forces

perpendicular to the surface of the joint (otherwise tissue slides along bone)

Normal ROMs in cervical spine

flexion - 60 deg

extension - 80 deg

rotation - 80 deg (40 upper, 40 lower cervicals)

Coupled motion C2-7

rotation (most upper) + lateral flexion (most lower)

Protrusion

upper cervicals - extension

lower cervicals - flexion

Retraction

upper cervicals - flexion

lower cervicals - extension

Cervical flexion characteristics

facets - superior move upward and forward (open)

foramen - size increases

spinal canal - size increases

nerve roots, dura, spinal cord - tensions

Cervical flexion characteristics

facets - superior move downward and backward (close)

foramen - size decreases

spinal canal - size decreases

nerve roots, dura, spinal cord - slackens

Foramen size w/rotation

contralateral size increases

ipsilateral size decreases

Nerve roots and dura with contralateral flexion (lat bend)

tensions

What muscle acts as a dynamic anterior longitudinal ligament (ALL)

longus colli (initiates + produces stabilization of cervical spine and flexion pattern)

Flexors are only ____ as strong as Extensors, why?

60%

b/c gravity assists flexion movements

Deep muscles control segments and

local muscles are weakened in upper cross syndrome

Superficial muscles produce movement and

global muscles are tight in upper cross syndrome

Common postural signs of lumbar spine

lumbar hyperlordosis

anterior pelvic tilt

foot flare

knee valgus

Lumbar hyperlordosis

faciliated by - erector spinae and hip flexors (psoas)

inhibited by - abdominals

Anterior pelvic tilt

facilitated by - hip flexors (iliacus) and quads

inhibited by - gluteals and abdominals

Foot flare

facilitated by - external hip rotators (piriformis)

inhibited by - internal hip rotators

Knee valgus

facilitated by - hip adductors

inhibited by - hip abductors (gluteus medius/minimus)

Muscles used to create posterior pelvic tilt

external oblique, rectus abdominis, gluteus maximus, hamstrings

Muscles used to create anterior pelvic tilt

erector spinae, iliopsoas, rectus femoris

Sitting

lumbar spine flexion occurs (increased stress)

Temporary tissue deformation occurs at _____ of sitting/sustained posture

~20min

LBP is aggravated by

sitting and long bouts of flexion

Full spine flexion

silence of lumbar extensors, passive tissues take over, muscles still produce substantial force elastically through stretching, shear loading

Is spinal flexion avoidable

NO!

People with and without LBP spend more time in

flexion

Is flexion during lifting a risk factor for developing LBP

NO!

Flexed back posture is associated with _____ strength and efficiency of back muscles compared to lordotic posture

increased

What leads to pain/injury with flexion

deconditioned/underprepared, psychological factors, hx of LBP and sensitization, genetics, sedentary lifestyle, lack of motor control and mobility

When to worry about flexion

when individual is sensitized to spinal flexion or it is aggravating in the acute stage

When are the two MC times injury occurs

early morning lifting

after prolonged sitting

Monitor painful triggers like

early morning lifting, lifting after prolonged sitting, monotonous lifting w/o variability in task, infrequency rests, stoop posture lifting, lifting w/arms away from body

Core container walls

diaphragm, pelvic floor, transversus abdominus, int/ext obliques, multifidus

Optimal stabilization requires

adequate compression of joints and equal dispersion of compression and tension forces

Proximal stability for distal mobility

stabilize and reduce excessive/compensatory movement in the spine while moving the distal extremities

Tensegrity (tensional integrity/ floating compression)

system of isolated components under compression inside a network of continuous tension (like the spine!)

Compression (applied) - gravity

Tension (absorbed) - neuromuscular system

Spine stability depends on

symmetry of muscle stiffness and forces all around spine

no single muscle must exert too much force/too little

amount of co-contraction particularly in the moment antagonists

geometry of muscle guy wires and rigid segments

neutral spine is preferred along with a broad base

Cervical flexion dysfunctional criteria

noticeable forward translation

upper cervical flexion occurs before lower

cannot touch chin to chest or non-uniform curve

Deep neck flexor endurance test terminated if

lose chin tuck

head positioning changes

shaky motor control

Men = 40sec, Women = 30sec

OA cervical flexion procedure

pt supine, dr passively rotates pt’s head as far as possible, pt tucks chin

normal = 20 deg

dysfunctional test indicates OA joint mobility dysfunction

C1/C2 procedure

pt supine, dr fully flexes cervical spine and passively rotates pt head

normal = >44 deg

increased likelihood of cervicogenic HA = <32 deg

Cervicothoracic differentiation test

dec pain or >10 deg of improved motion is a positive test

suggests thoracic manipulation may provide benefit

Cervicothoracic differentiation test - Rotation most painful

pt turns upper thorax opposite from side of cervical rotational pain

dr stabilizes position and pt repeats the painful cervical rotation