Biomechanics Flashcards
(45 cards)
0
Q
Why study biomechanics?
Look at diagram on page 2 of notes
A
- AT, OT, PT students will benefit from learning biomechanics because it will help in:
- Determining the cause of injury
- Aid in preventing future injury
- Guide in determining best methods for rehabilitation
1
Q
Why study Biomechanics?
A
- Traditional teaching and coaching methods tell you what techniques to teach.
- Biomechanics tells you why those techniques are best to teach
- Tells you why some teaching and coaching techniques don’t work and need to be discontinued
2
Q
Why study biomechanics?
A
- Exercise science students will learn the best techniques for improving fitness and enhancing exercise performance
- Technique Improvement
- Improve current technique
- Develop new technique
- Equipment Improvement
- Shoes and apparel
- Implements
- Protection devices
- Training Improvement
- Rehabilitation and Therapeutic Techniques
3
Q
Why study biomechanics?
A
- To understand how people move…normal gait patterns
- Back in the day… They viewed people running naked to see all the muscles in the body and took pictures at different stances
4
Q
Why study biomechanics?
A
- To understand how people move…normal gait patterns.
- Today… They have video cameras that are set up all around a force plate where they can measure how much pressure you are exerting on your feet and where the pressure is located and the cameras can capture any part of the person’s running form.
5
Q
Why study biomechanics?
A
- To understand how people move…
- To enhance skill performance for all individuals
- Physical challenges
- ACL deficit
- Cap gait
- Wheelchair
- Age-related disease
6
Q
What are the 9 areas of study, research, and careers?
A
- Sport and Exercise Science
- Coaching
- Ergonomics
- Equipment Design
- Gait & Locomotion
- Orthopedics-Rehabilitation
- Physiotherapy
- Occupational Therapy - Prosthetics and Orthotics
- Motor Control
- Computer Simulation
7
Q
What is the introduction to biomechanics?
A
- During the past decade the term BIOMECHANICS has emerged as an area of inquiry in the sport science domain;
- Clinical Biomechanics
- The application of biomechanics to the treatment of patients
- Sports Biomechanics
- The study and analyses of human movement patterns in sport
- Biomechanics Engineering
- The application of engineering principles and design concepts to medicine and biology for healthcare purposes (diagnostic or therapeutic)
8
Q
What is Biomechanics?
A
- Biomechanics: Bio=Living
- Mechanics = Forces & Effects
- The application of mechanics to the living organism
- The study of forces and segment movement as they relate to human movement
- Combines engineering with anatomy and physiology
- Two divisions
1. Kinematics
2. Kinetics
9
Q
What is Kinematics?
A
- The branch of mechanics that describes the motion of objects
- The description of movement related to
- Displacement
- Velocity
- Acceleration - Can be described in two dimensions (plantar motion) and three dimensions (spatial motion).
10
Q
What are some of the basic Kinematic terms?
A
Units of kinematic measurement
- Displacement
- Velocity
- Acceleration
11
Q
What is displacement of the basic kinematic terms?
A
- Change in position (meters, degrees)
- Example: 123 degrees knee flexion active range of motion is a measure of angular displacement
12
Q
What is velocity of the basic kinematic terms?
A
- Rate at which an object moves in a given direction (meters/second)
- change position/change time
- Has a directional component, speed does not
13
Q
What is acceleration of the basic kinematic terms?
A
- The rate of change of velocity with respect to time (m/s squared)
- Change velocity/ change time
14
Q
What is linear Kinematic?
A
- Occurs when all points move equidistant in the same direction, at the same time
- Can occur in a straight line (rectilinear) or with curvature (curvilinear).
15
Q
What is Angular Kinematics?
A
- Occurs when an object moves along a circular path
- AKA rotation (clockwise or counter-clockwise)
- Measure in degrees or radians
16
Q
What is Kinetics?
A
- The branch of mechanics used to describe motion in terms of force
- Newtons three laws of motion form the basis for kinetics
- Basic Kinetic Terms
- Mass
- Inertia
- Momentum
17
Q
What is mass?
A
- The amount of matter that makes up an object
- The greater the mass, he harder the object is to move
- Measured in pounds (lbs.) or kilograms (kg.)
- Different from weight
18
Q
What is center or mass?
A
- The point about which the body’s mass is evenly distrusted
- Can be applied to the whole body or one segment of the body
- Some changes with different body positions and limb positions
19
Q
What is inertia?
A
- The amount of energy required to alter a body’s velocity
- Directly related to the mass of an object
- Clinical coordination:
- The risk of an ankle sprain potentially increases with an increase in body weight because of increasing movement of inertia acting about the ankle
20
Q
What is momentum?
A
- The quality of motion of an object and is equal to the mass in the velocity of an object (P=mv).
- Increasing The mass or velocity of an object increases the momentum
21
Q
What is clinical coordination within forces?
A
- Injuries are caused from abnormal forces on the body
- The type and extent of injury is based on the:
- Magnitude (the load)
- The location (where the force was applied)
- Direction
- Duration (how long)
- Frequency (how often)
- Rate (how quickly applied)
22
Q
What is a force?
A
- A force is the action of one body on another
- A vector with:
- Magnitude
- Direction
- Point of application
- Line of application
- The units for force are Newton’s or pounds
- A Newton is the force required to accelerate 1 kg mass a 1m/s squared
23
Q
Can forces be both internally generated or externally generated?
A
- YES
- Forces can be internally generated, or act on the body from external environment
- Internal example: muscle contraction
- External example: gravity
24
Name three specific types of forces?
1. Tensile forces
2. Compressive forces
3. Shear forces
25
What is tensile forces?
- Collinear forces acting in opposite directions to pull an object apart
- Example: ligamentous sprain
26
What is compressive forces?
- Collinear forces acting in similar directions to push tissues together
- Example: compression fracture
27
What is shear forces?
- Coplanar are opposite in direction, the forces cause one service of a body to slide past an adjacent surface
- Example: blister
28
What are beneficial forces?
- When we move from a nonweightbearing to a weight-bearing position…
- compressive loading on lower extremity joints
- compression at the joints to promote nourishment
- forces increase as weight increases
- injury to cartilage will occur when the forces become more than the tissue can handle
29
What is a force system?
-A force system is any group of two or more forces in relation to an object
30
What are some examples of force systems? There are five
1. Linear
2. Parallel
3. Concurrent
4. General
5. Force couple
31
What is a linear force system?
Two or more forces acting on the same line
32
What is a parallel force system?
Forces acting on an object in the same plane that are parallel but not collinear
33
What are concurrent force systems?
Forces with the common origin
34
What are general force systems?
A system of forces that includes a combination of linear, parallel, or concurrent
35
What are force couple systems?
Parallel forces that are opposite and equal in magnitude with the axis midway between, creating rotation of an object
36
What is friction?
- Friction is an opposing force that impedes or opposes motion between two contracting
- The resistance from friction is the result of molecular bonding between materials
- Static friction refers to no movement occurring between bodies
- Kinetic friction occurs when movement occurs between bodies creating a sliding force
- 0= frictionless surface
- ice on ice =0.05
- Basketball shoe on a wood floor =1.0
37
What is the clinical coordination of friction?
- Lack of friction could lead to falls
- High levels of friction could lead to quick deceleration and injury to tissue
- Friction between healthy articular surface is very low due to synovial fluid (0.01)
- Damage to cartilage increases the friction at the joint leading to irregular mechanics
- Artificial joints attempt to re-create the natural, frictionless mechanics
38
Describe Newton's laws of motion?
- Newton's laws describe the relationship between the forces acting on the body and the resultant motion due to those forces
- Three laws
1. Law of Inertia
2. Law of acceleration
3. Law of action-reaction
- Clinically it is important to understand these laws as it explains injury mechanics and concept of exercise prescription
39
Describe newton's law of inertia?
-A body at rest will remain at rest, or a body in motion will stay in motion (move in a straight line with constant velocity), unless acted upon by resultant force
40
Describe Newton's Law of Acceleration?
- A body subjected to a resultant force will accelerate in the direction of that force, and the magnitude of the acceleration will be proportional to the magnitude of the force
- Force equals mass times acceleration(f=mass x acceleration)
- Clinical coordination:
- Whiplash injury
- Non-medical term describing a range of injuries to the neck caused by a sudden distortion of the neck associated with extension
- A.K.A. cervical acceleration-deceleration
41
Describe newton's law of action-reaction?
- For every action there is an equal and opposite reaction
- Forces of action and reaction between interacting bodies are:
1. Equal in magnitude
2. Opposite in direction
3. Have the same line of action
- Example: ground reaction forces (GRFs)
- when you take a step, jump, leap, etc., the force exerts a force onto you that is equal in magnitude
42
What is work?
- Work is a force applied over a distance
- Work = force x distance
- Measured in Joules (Nm)
- Work is only done when an object is moving
- Example:
- Holding a 10 pound weight in your hand, bicep is exerting an isometric force, but is not moving anywhere
43
What is pressure?
- Pressure is a given amount of force applied within an area
- Example: a sharp object hurts more than a blunt object when pressed against the skin as the surface area has increased
- Pressure equals force times area (P= Force x area)
- Measured in Pascal's (1Pa=1N/m squared)
- Clinical coordination
- Measure center of pressure (COP) using a force platform and by knowing the dimensions of 1 foot
- COP is the point at which the weight of the object is transferred to the support surface
44
What is power?
- Power is the rate of work
- Power=Work/Time
- Measured in Watts (1Watt= 1 J/s1)
- A given amount of work performed in a shorter amount of time will have a greater power output
