kinesiology I - introduction to kinesiology

what is kinesiology?

study of movement

active and passive structures involved

kinematics

bodies in motion (2 types--> translation + rotation)

translation

all parts of a rigid body move PARALLEL to and in SAME direction as every other part of the body

rotation

rigid body moves in a CIRCULAR path around some pivot point

ex: ball rolling down a ramp

what are the two kinematic chains?

open kinetic chain

closed kinetic chain

open kinetic chain

distal segment is moving (NOT FIXED) on the proximal segment
ex: throwing a football

closed kinetic chain

Proximal segment is moving on distal segment (FIXED)
ex: push up

is a squat open or closed kinetic chain?

BOTH!

closed--> at the knees, the femur moves on the tibia (proximal moving on distal)

open--> at the illiofemoral joint, the femur is moving upon the pelvis (femur is distal to pelvis)

what does "GAP" mean with goniometry?

"GAP"

A- active ROM --> patient moves FIRST
P- passive ROM --> physical therapist adds overpressure

concave on convex

roll and slide occur in the same direction

"CC" = ConCave --> SAME

convex on concave

roll and slide occur in opposite directions

"CV" - ConVex --> different

osteokinematics

descriptions of the motions of bones relative to the 3 cardinal planes

saggital plane

divides the body into a right and left side

corresponds to z-coordinate

frontal (coronal) plane

divides the body into anterior and posterior parts

corresponds to y-coordinate

transverse plane

divides the body into upper and lower halves

corresponds to the x-coordinate

arthokinematics

description of motion between articular joint surfaces

-roll, slide/glide, pivot, spin, compression, distraction

roll (arthrokinematics)

multiple points along 1 rotating articular surface contact multiple points on another articular surface

1 bone rolling on another
ex: in shoulder abduction, the humeral head rolls superiorly in the glenoid fossa

spin (arthrokinematics)

a single point on 1 articular surface rotates on a single point on another articular surface

1 body spinning on another
ex: posterior spin of the femoral head in the acetabulum during hip flexion

slide/glide (arthrokinematics)

a single point on 1 articular surface contacts multiple points on another articular surface

sliding of 1 joint surface over another
ex: during a squat the femur rolls posteriorly and slides anteriorly on the tibia (convex and concave--> roll/slide occurs in opposite directions)

kinetics

the effect of forces on the body

force is a push or pull that can produce, arrest, and modify movement

forces

both internal and external forces act upon the body

produce joint motion if perpendicularly oriented to axis of rotation (torque)

internal forces

produced from structures located within the body

may be active or passive

active internal force

muscle

passive internal force

periarticular connective tissue, ligaments, joint capsules, etc

external forces

forces acting upon the body, that are outside the body

musculoskeletal torques

produced by forces applied perpendicular, at some distance to the axis of rotation

moment arm--> is the perpendicular distance between axis of rotation and the force

product of the moment arm and force produces ---> torque

isometric muscle contraction

no motion occurs
no change in muscle length

concentric muscle contraction

active shortening
ex: bicep curl

eccentric muscle contraction

active lengthening
ex: coming down from bicep curl

why is the elastic region in the stress-strain relationship good for post op patients?

the tissue already changed from surgery, therefore we want to stay in the elastic zone to ensure we protect it and prevent more change

if a patient has been dealing with the same chronic back injury for 15 years, what region of the stress-strain relationship curve should we want them in?

plastic zone, because he patient needs some sort of change, furthermore we are wanting a permanent change to the tissues to try and help

what does the ultimate failure point on the stress-strain curve mean?

mechanical failure, there was enough stress produced to fail/break/tear the material

viscoelasticity and creep

slow, constant deformation of a viscoelastic material caused by prolonged load/stress

creep --> reversible

ex: bungee cord hung from ceiling is holding a heaving object, overtime the bungee cord lengthens

agonist muscle action

prime mover, directly produces a desired movement

ex: biceps are agonist to bicep flexion

antagonist muscle action

muscles having the opposite action of agonist

ex: while doing a bicep curl, the agonist will be the biceps and the antagonist will be the triceps

synergist muscle action

a muscle that contracts at the same time as a prime mover and assists it in carrying out its action

ex: brachialis is the synergist because it assists the biceps brachii when lifting a cup up

force couples

2 or more muscles on opposing sides of a joint work together to provide joint stability/create movement