(Kin) End of Module 2 to Module 3 Flashcards
- Human factor and ergonimcs - Gait cycle - Nervous system
Movement Assessment - Why is it important to be excellent observers of human form and movement?
- Skill development - coaching, training, injury risk reduction
- Clinical - retraining, recovery, rehab.
- Occupational - task training, injury risk reduction
Overall tips for movement assessment
- use correct language
- line of sight (plane of movement, view perpendicular to the motion)
- difference between static and dynamic movement
- focus on one joint in a plane at a time
- be organized when examining multiple joints (create tables)
- recording to review, camera position is perpendicular
What is human factor/ ergonomics (HFE)?
application of theoretical principles, data and methods to workplace design to optimize human well being.
An approach to design/systems/ products that humans can seemingly interact too.
Fitting environment to human
Why do we need human factor/ergonomics? (2 major effects)
Fitting the environment to the human leads to 2 major effects:
- Performance enhancement:
- better user experience
- shorter time of familiarisation, better fit, fewer mistakes - Well being:
- physical, social wellbeing
- motivation, growth, job satisfaction
- improved performance
What is a major domain of human factor and ergonomics that starts with an O , details and examples
Organizational:
- On a macro level to understand interactions
- how different points of leverage in a system can affect interaction between people
- ex. better resources for nurses
What is a major domain of human factor and ergonomics that starts with a P, details and examples
Physical:
- workplace layout and design to prevent harm/injuries
- ex. maladapated offices causes aches and strains
What is a major domain of human facotr and ergononmics that starts with a C, details and examples
Cognitive:
- task analysis + task analysis techniques
- how do humans behave / desicion making
Objectives when observing static positions?
- provide a description of the joint(s) relative to the anatomical or neutral position
- description of the joint angle based on body segments adjacent to the joint
- isolate joint in a specific plane
- no distraction from proximal segment or other joints
Objectives when observing dynamic positions?
- Assessing changes in joint(s) angle over time in phases
- an understanding of movement is needed in assessing multisegment dynamic movement
- isolate joint in complex movement
- repeated observations of a cycle or joint movement over time
The Gait cycle: a step can be partitioned in two phases, what are they?
- The stance phase
- The swing phase
When is the stance phase intiated? When does it end?
When a foot strikes the ground and ends when it is lifted
When is swing phase initiated? When does it end
When the foot is lifted and ends when it strikes the ground again
What does one complete gait cycle consist of? What can it also be called?
the time interval or sequence of motions occurring between two consecutive intial contacts of the same foot (ex. heel strike of same foot twice)
One gait cycle can also be called one stride
What is a step
one half of a stride, it takes two steps (one right step and one left step)
How many steps does it take to complete a stride/one gait cycle
3
What are the three types of nervous systems?
Central Nervous system, Peripheral nervous system, Autonomic nervous system
What is the central nervous (CNS) made up of? What are they protected by?
Brain and spinal cord, protected by bony structures
Peripheral nervous system (PNS) where does it exist, what nerves does it include?
its nerves exists outside the CNS.
Somatic component includes sensory nerves (detecting environment through senses) and motor nerves (skeletal muscle)
How do neurons in nervous system send signals
via action potentials
Autonomic Nervous system (ANS), what are its functions? What are the two branches of this system?
control system of body functions , ex. breathing, cardiovascular function , internal organs that cant be consciously controlled
Sympathetic branch and parasympathetic branch
What are the ridges of the cerebral cortex called?
gyrus
What are the grooves of the cerebral cortex called?
sulcus
Substructures of cerebrum (3) , and their functions
- Cerebral cortex (increased SA with gyrus and sulci)
- Amygdala (long term memory)
- Hippocampus (long term memory)
Where is the bulk of grey matter (cell bodies) in the brain?
Cerebrum
Substructures of the Diencephalon (2), and their functions
- Thalamus (involved with the sensory nerves of PNS)
- Hypothalamus (involved with maintaining homeostasis)
What does Cerebellum consist of that contributes to its SA, what is its function?
consists of ridges and grooves to increase SA
Maintain balance if muscles
Main function of the Brain Stem
Controls the autonomic nervous system features (Heart rate, blood pressure)
Substructures of the Brain stem (3)
- Midbrain
- Pons
- Medulla (cardiovascular control)
What is the spinal cord protected by
Vertabrae
What is grey matter of the brain and what does it consist of?
- a type of tissue in the brain + spinal cord (central nervous system)
- areas of synaptic connections (“neuron action”)
- consist of cell bodies, dendrites, axon terminals
What is the white matter of the brain and what does it consist of?
- allows the exchange of information and communication between different areas of your brain
- consist of axons
- creates pathways between grey matter areas
Where is peripheral nervous system coming from?
peripheral nerves project out of the spinal cord at every vertebrae forms the peripheral nervous system
What are the two types of peripheral nerves
- motor nerves aka efferent neurons
- Sensory nerves aka aka afferent neurons
What is a motor nerve of the PNS and what is its other name?
Other name is efferent neurons:
- Controls effectors ex. skeletal muscle
- sends signals from grey matter to the tissue
Function of sensory nerve of the PNS and what is its other name?
Other name is afferent nerves:
- detects stimuli
- relays sensory information to the CNS
What is a neuron’s general function?
- Basic information processing unit
- receives input
- processes information
- provides output
What do neurons have that allow them to do work?
Membrane potential - a difference in electrical energy charge between inside and outside of neuron
experience depolarization and repolarization
What is the charge on the inside of a neuron cell when it is at rest?
Negative at rest , -70 mV
What does depolarization mean?
membrane potential becomes positive
What does repolarization/hyperpolarization mean?
membrane potential becomes negative.
Brings cell back to resting potential
What are dendrites
finger like projections on a neuron that recieves information from other neurons
What is a synapse
The connection when a neuron interacts with another neuron or cell type.
Involves the release of neurotransmitters
What is an axon hillock
in between the axon and processing section of a neuron, which determines whether or not an action potential will be fired down axon after recieving information from the dendrites
What kind of signals do dendrites receive? (2) Where are these signals followed
- Turn on signals - depolarize to create an action potential
- Turn off signals - stays where they are
Followed by Axon illock
What are the two sections that make up a neuron ?
- Processing section (determines if an action potential is created)
- Communication section (movement of those signals through axon)
Purpose of gilial cells
cells in nervous system that support the strucutre, function, metabolism and repair of neurons
What is the process of an action potential
Going from the negative membrane potential to positive membrane potential through depolarization
What is a threshold in a neuron, what components of the neuron are involved
point needed to be met in order for an action potential to occur , controlled by the axon hillock
The _________ signal is converted to a _________ signal at the axon terminals
electrical , chemical
The _______ signal is converted to an ________ signal at the post synaptic neuron
chemical, electrical
How does an electroencephalography (EEG) measure the CNS and PNS
- measures electrical activity of the brain
- measures neuronal activity, action potentials
What is a Biopotential, what can measure biopotential?
An electric potential measured betwen two points in living cells, tissues, organisms.
Use electrodes, amplifiers, electrical activity
What is a sarcomere? What is made up of? What is it a component of?
- Fundamental unit of skeletal and cardiac muscle
- made up of actin and myosin filaments)
- many myofibrils make up a muscle cell
- make up a myofibril
Three types of muscle cells?
Skeletal, cardiac, smooth
What are Myofilaments
highly arranged structure within the muscle cell (sarcomere)
- composed of actin and myosin that interact with eachother to generate force
They are smaller structures of myofibrils
What is Sarcolemma
cell membrane of the muscle cell
How is force generated within muscle cell
myofibrils consists of sarcomeres that shorten so the Z-ends get closer together, which produces force. Requires NRG
What is the Cross bridge theory
binding of actin to myosin myofilaments to make cross bridgesand change in the confirmation myosin.
What does the sliding filament theory explain?
Theory explaining the mechanism of muscle contraction associate ih the cross bridge cycling and sliding of myofilaments past eachother to generate force.
What is a motor neuron
Neuron that synapses with skeletal muscle cells through action potentials
What is a Motor unit
motor neuron AND all the muscle cells it interacts with
What is a Neuromuscular junction
synapse between motor neuron and skeletal muscle cell
What is muscle action potential
action potential on the membrane of a skeletal muscle cell
Neuromuscular activation: what kind of signal is there during the depolarization of a motor neuron
electrical
Neuromuscular acitvation: what kind of signal is released when neurotransmitter release at the neuromuscular joint
chemical
Neuromuscular activation: what kind of signal is released during the depolarization of a muscle fibre
electrical
Neuromuscular Activation: what kind of signal is released during the cross-bridge formation and sarcomere shortening
mechanical
Neuromuscular activation: what is the neurotransmitter released at neuromuscular junction
Acetylcholine (ACh)
Since muscles activate in an “all or non manner” , how can the amount of force be controlled?
- Motor unit recruitment (control amount to activate)
- The amount of Action potential frequency
What determines the max. isometric force a muscle could generate?
“cross sectional area” of muscle
(more sarcomere, more force, more crossbridges)
What is the y-axis on EMG tracing?
milivolts
What is the x-axis on EMG tracing?
time
What is EMG? What are the two types of EMG?
electromyography; a technique to measure the electrical activity (action potentials) produced by muscles.
1. Surface
2. Intramuscular
Advantages/Disadvantages of surface EMG?
Advantages: non-invasive
Disadvantage: will be placed on superficial muscle, so it may be innacurate, interference from surface
Advantages/Disadvantages of intramuscular EMG?
Advantages: precision
Disadvantages: invasive
is there a relationship between EMG amplitude and muscle force?
A positive relationship, but cannot compare it between different muscles and people
What is a stimulus response? Give the order of what the process are involved
The neural information being processed (after following prior behavioural instructions)
stimulus -> sensory (afferent) -> cortical (processing) -> motor (efferent)
What is reaction time?
the time it takes the CNS to sense, process and initiate a response to a stimulus
What is movement time?
- time it takes for a movement to be executed
- onset of muscle activation to the end of the response
- reaction time is not included
What is response time?
- reaction time + movement time
- total time from stimulus detection to end of response
What are some factors reaction time is dependent on (3)?
- stimulus intensity and modality
- simple reaction time (SRT)
- choice reaction time (CRT)
What is stimulus intensity and modality?
Just refers to the type of stimulus that is a factor to one’s reaction time (visual, auditory)
What is simple reaction time (SRT)
there is only one stimulus and one response
What s choice reaction time (CRT)
There are a number of different stimuli presented each requiring a different response
What is dual task interference?
Simultaneous performance of two tasks leads to performance deficits
What is reciprocal contraction
the simultaneous activation of the agonist and inactivation of the antagonist
What is co-contraction
Simultaneous activation of the agonist and antagonist
stabilizing the joint
What are biomechanics
Study of the effects and control of forces that act on/produced by living beings
What are Kinematics
the study of the motion of objects
Kinetics
the study of forces that cause motion
What is Force? What are its units?
an action or influence that moves the body or influences the movement of the body.
Units = Newtons (N)
Moment? What are its unit/what do you need to achieve this?
Force that changes the rotational motion of an object
Units = N . m (newton metres)
What is the “m” in the moment equation? (N x m)? How can it be used to maximize moment force
moment arm - perpendicular distance from application of force
distance between pt of rotation and application of force
maximize force by increasing moment arm
What is needed when needed to calculate the force of gravity on an object?
the centre of mass - the point where the mass of the object is equally distributed in all distributions
acceleration due to gravity (9.8m/s^2)
F = m x a
dont forget direction of acceleration (-9.8)
Goniometer and potentiometer. their pros/cons?
Used to measure kinetics
An instrument to measure angles
cons; inacurate, a guess, potentiometer only stay in one spot
pro; can be done anywhere/anyone
Inertial sensors
measure acceleration
gold standard for kinematic analysis
optical/magnetic motion capture
Measurement methods for kinematics? (4)
- visual observation
- Goniometer
- Inertial sensors
- Optical or magnetic motion capture
Measurement methods for kinetics (study of forces that cause motion) ?
- Manual assessment
- Dynamometer (hand held or isokinetic)
- Force plates
Dynamometer
device measuring force , torque, power
control the speed of contraction, joint angle
Gold standard for kinetic analysis
Force plates
Force plates
measures how people interact with their environment
measures force in 6 directions
