Week 1 Flashcards
What is the difference between kinematics and kinetics?
- kinematics - motion of a body, without regard to the forces or torques that may produce the motion
- kinetics - describes the effect of forces on the body
Define and give an example of the 2 types of motion: translation & rotation
- translation - linear motion in which all parts move parallel to and in the same direction ex: walking straight
- rotation - body moves in a circular path around some pivot point ex: flexion to extension
What are the 2 types of translation motion? Give an example of each
- curvilinear ex: walking (bobs up and down)
- rectilinear ex: sliding box on the floor
List the planes, their associated axis and the motions that occur in those planes
- sagittal - medial to lateral axis - flexion/extension, dorsi/plantarflexion, forward/backward bending
- frontal - anterior to posterior axis - ab/adduction, lateral flexion, ulnar/radial deviation, eversion/inversion
- transverse - superior to inferior axis - internal/external rotation, axial rotation
Define and give examples of open kinetic chain exercises and closed kinetic chain exercises
- Open kinetic chain - distal segment is not fixed and it is free to move. ex: bicep curl, throwing a ball
- closed kinetic chain - distal segment is fixed, proximal segment is free to move - squat, pull up, stance phase of gait
Compare and contrast the differences of osteokinematics vs arthokinematics
- osteokinematics - movement of bones, open or closed kinetic chain
- arthokinematics - motion that occurs between joint surfaces, convex and concave
What are the purposes of the convex-concave relationship?
- improve joint congruency
- increase surface area for dissipating contact forces
- helps guide motion between bones
Define the convex/concave rule
- convex on concave - roll and slide move in opposite direction
- concave on convex - roll and slide move in same direction
What is closed packed vs loose packed position? Why is it clinically important for us to know the loose and closed packed position of each joint?
- closed-packed - position of maximal congruency, usually near end range, most ligaments and capsule are taut, stable
- loose-packed - all positions other than closed-packed, least congruent near midrange, ligaments and capsule are slack, allows for increased accessory movement
- important to know positions for manipulations
Draw, label and define the stress-strain curve
- see slide 25 in ppt 1
- elastic region - range which muscle can be stretched: toe region - area must be taut before tension is measured, linear region - after slack is taken up, linear relationship between stress and strain
- plastic region - point of no return: yield point - elongation occurs beyond physiologic range, ultimate failure point - tissue is partially or completely separated
Define and describe the 2 properties of viscoelasticity
- time and rate dependent
- over time creep occurs - progressive strain of a material when exposed to a constant load over time
- as rate of loading increases, slop increases throughout elastic range, decreased viscosity with loads applied slowly and increased viscosity with loads applied rapidly
Define and give examples of internal and external forces
- internal force - produced within the body ex: muscle contraction
- external force - force produced outside the body ex: gravity, free weight
Describe and provide examples of 1st, 2nd and 3rd class levers
- 1st - axis of rotation is between opposing forces (balance) ex: yes/ no w/ head and neck extensor muscles
- 2nd - axis of rotation is at 1 end, resistance in middle and force at other end (power) ex: wheelbarrow, toe raises
- 3rd - axis at 1 end with the force in the middle and resistance at the opposite end (speed and distance) ex: elbow flexors
What is mechanical advantage? What is MA of each lever?
- ratio of internal movement arm to external movement arm
- 1st - less than, equal, or greater than 1
- 2nd - always greater than 1
- 3rd - always less than 1
Define the following terms agonist, antagonist, synergists and force couples. Provide examples.
- agonist - most directly related to initiation and execution of a particular movement. ex: tibialis anterior is agonist for dorsiflexion
- antagonist - considered to have opposite action of a particular agonist. ex: gastroc and soleus are antagonists to tibialis anterior
- synergists - muscles that cooperate during the execution of a particular movement. ex: flexor carpi ulnaris and flexor carpi radialis during wrist flexion
- force couple - when 2 or more muscles simultaneously produce force in different linear directions but produce torque in the same direction. ex: erector spinae and iliopsoas muscles during anterior pelvic tilt
Define concentric, eccentric, isokinetic and isometric contractions. Provide examples.
- concentric - shortening contraction ex: bicep curl
- eccentric - elongating contraction ex: sitting down
- isokinetic - ability to adjust resistance throughout ROM of the muscle to account for stronger/weaker areas ex: biodex
- isometric - maintaining constant length, allows contraction of muscle w/o movement through full ROM ex: wall push
Describe the active and passive insufficiency. Give examples of each.
- active - the point at which a 2-joint muscle reaches a point where it cannot shorten any farther ex: standing hamstring curl
- passive - when a muscle is of insufficient length to permit full ROM ex: unable to touch toes w/o bending knees
Describe the force-velocity curve
- concentrically - velocity of muscle shortening is inversely related to external load (increase load = decrease speed)
- eccentrically - velocity of muscle lengthening is proportional to the external load (increase load = increase speed)
Describe the force-time relationship
- the force generated by a muscle is proportional to the contraction time
- the greater the contraction time, the greater the force up to maximum contraction
Describe how to stretch a 1-joint vs 2-joint muscle by using an example in the body
- 2 joint muscles must be placed on slack to stretch 1 joint muscles
ex: runners stretch for gastroc, must bend knee to stretch soleus
Compare and contrast Synarthroses vs Diarthroses
- synarthroses - no movement, function to bind and transfer forces between bones, fibrous and cartilaginous connective tissue
- diarthroses - moderate to extensive motion, synovial fluid-filled cavity
List the 7 elements always associated with diarthrodial joints. What do they do?
- synovial fluid - coats surfaces of joints to decrease friction and provide nourishment
- articular cartilage - covers articular surface
- joint capsule - enclose joint
- synovial membrane - internal layer of articular capsule
- ligaments - protect from excessive movement
- blood vessels - provide blood supply
- sensory nerves - innervation
List the 5 elements that are sometimes associated with diarthrodial joints. What do they do?
- intra-articular discs or menisci - increase congruency and improve force dispersion
- peripheral labrum - deepen concave joint and support attachment of joint capsule
- fat pads - reinforce internal aspects of capsule and fill non-articulating joint spaces
- bursa - absorb force and protect periarticular connective tissue
- synovial plicae - helps to further reinforce the joint by including an over thickened area
List the 7 types of synovial joints and an example of each
1) hinge - elbow
2) pivot - humeroradial joint (capitulum)
3) ellipsoid - radiocarpal joint
4) ball and socket - shoulder
5) planar - carpometacarpal joints
6) saddle - sternoclavicular or carpometacarpal of thumb
7) condyloid - knee
Characteristics of dense connective tissue - what does it include? primary function, irregular or regular or both
- ligaments/tendons, fibrous layer of joint capsule,
- limited blood supply
- primary function to resist tension
- irregular to resist force in multiple directions (joint capsule) and regular to resist stretched parallel to ligament forces (ligaments/tendons)
Characteristics of articular cartilage - what does it include? primary function
- specialized hyaline cartilage
- primary function is to distribute and absorb joint forces and reduces joint friction
- avascular and aneural
- receives nutrition with compression
Characteristics of fibrocartilage - what does it include? primary function
- mixture of dense and articular cartilage
- menisci, labrum, discs
- primary function is to support and mechanically stabilize joints, dissipate loads across multiple planes and guides complex arthokinematics
- aneural and limited blood supply to outer rim
Characteristics of bone - what does it include? primary function
- type 1 collagen, osteoblasts and hard ground substance
- primary function is rigid support and systems of levers for muscles
- can accept tremendous compressive loads
- richly vascularized and innervated
What is Wolff’s law and how is it clinically relevant?
- bone will adapt to the loads under which it is placed
- Dehydrated disc puts more stress on vertebral body which may cause synthesis of more bone (osteophyte)
- Rapid decline in bone mineral density after spinal cord injury
What type of force is cortical bone the strongest to resist?
compression
How does immobilization impact connective tissues?
- changes in structure and function
- rate of decline is dependent on metabolic activity of the tissue
- rapid loss of strength occurs with prolonged reduce loading and recovery is slower
Define Newton’s 1st Law
- Law of Inertia
- body remains at rest or constant linear velocity until acted on by another force
Define Newton’s 2nd Law
- Law of Acceleration
- the linear acceleration of a body is directly proportional to the force causing it, takes place in the same direction in which the force acts and is inversely proportional to the mass of the body
- acceleration happens when a force acts on it
Define Newton’s 3rd Law
- Law of Action-Reaction
- for every force there is an equal and opposite directed force
- ex: walking force against ground is same as ground reaction force back up through foot
List the ways that we can objectively measure human movement
1) Do not take into consideration the forces that are involved at play
- electrogoniometry
- accelerometery (fitbit)
- imaging techniques (Kinect)
2) take into consideration the forces that are going to produce the motion
- mechanical devices -scale, grip dynamometer
- transducers - force plates
- electromechanical devices - isokinetic biodex
