KHS 301 Exam 1

Biomechanics

The study of forces & their effects on living systems

Exercise and Sport Biomechanics

The study of forces & their effects on humans in exercise & sport

Systems

any structure or organization of related structureswhose state of motion is of analytical interest

Why Study Biomechanics

• Improve sports performance by learning how to analyze human movements

- Expert observation, video, comparison to athletes/standards

• Effectively coach specific athletic skills

• Maximize efficiency & effectiveness

• Reduce the risk of injury

Qualitative

breaking down movement into basic elements & qualitatively examining these elements from a biomechanical perspective

- Observations & knowledge of skill technique

- Coaching, clinicians, teaching, therapy

- Motor skill analysis

Quantitative

biomechanicalanalysis that is measurable

- Numbers

- Systematic problem solving

• A) What information is given?

• B) What is the desired finding?

• How do I get from A to B?

- Mathematical formulas

Given, Diagram, Formulas, Units, Solution

Problem Solving Order

sine

opposite/hypotenuse

cosine

adjacent/hypotenuse

tangent

opposite/adjacent

Pythagorean Theorem

a²+b²=c²

Kinetics

forces that cause motion

• Scale: body mass & center of gravity

• Force/pressure transducers, strain gauges, & plates: measure force & pressure

- Isokinetic/isometric dynamometers

• EMG, MRI: force, neuromuscular characteristics

• Visualization of performance- Strength testing with free weights

Kinematics

study of motion

• Time, displacement, velocity, acceleration

- Timing devices: stopwatch, infrared sensors

- Video & and computer analysis: filming, digitizing

- Length measurement: tape measure, transducer- Goniometer/electro goniometers: ROM

- Accelerometer: acceleration of body segment

- Velocity: radar gun

Physiology

neural, muscular, connective tissue,metabolic, endocrine, cardiovascular, thermal

Anatomy

structure

Biochemistry

blood/muscle/CT analyses

Molecular Biology

cell function

Anatomical and Standard Position

Starting Positions for Movement Description

Anatomical Position

What's this

Center of Gravity

imaginary point representing the weight center of an object

Line of Gravity

imaginary vertical line that passes through COG

dynamic

The center of gravity is BLANK - changes with the body

Superficial

toward or the at body surface

Deep

Away from the body surface; more internal

sagittal plane

a vertical line that cuts the body into right and left sides

- moves forward and back

Frontal plane

vertical plane that cuts the body into anterior and posterior parts

- moves side to side

Transverse plane

horizontal plane that cuts the body into superior and inferior parts

- rotational

Degrees of freedom (planes of motion)

number of ways a system can move

Antero-posterior axis (sagittal)

- perpendicular to the frontal plane

- limiting motion to forwards and backward

Transverse axis

- perpendicular to the sagittal plane

- limiting motion to side-to-side

longitudinal axis

- perpendicular to transverse plane

- limiting motion to rotation

Sagittal Plane joint action

- Flexion

- Extension

- Hyperextension

- Dorsiflexion

- Plantar flexion

flexion

Decreases the angle of a joint

- elbow, shoulder, pelvis, knee, abs, neck

extension

increases the angle of a joint

- elbow, shoulder, pelvis, knee, abs, neck

Hyperextension

extension beyond anatomical position

- elbow, shoulder, pelvis, knee, abs, neck

Dorsiflexion

bending of the foot or the toes upward

- ankle

Plantar Flexion

bending of the sole of the foot by curling the toes toward the ground

- ankle

scapula

BLANK has an up/tilt in the sagittal plane

pelvis

BLANK has an anterior/posterior tilt in the sagittal plane

frontal plane joint actions

- Abduction

- Adduction

- Lateral flexion

- Elevation

- Depression

- Eversion

- Inversion

- Radial deviation

- Ulnar deviation

- Up/down rotation

- Lateral tilt

Abduction

Movement away from the midline of the body

- shoulders, hips

adduction

Movement toward the midline of the body

- shoulders, hips

lateral flexion

Side-bending left or right

- neck, hips

elevation

raising a body part

- traps, hips

depression

lowering a body part

- traps, hips

eversion

turning outward

- ankle

inversion

turning inward

- ankle

radial deviation

Movement of the wrist towards the radius or lateral side

ulnar deviation

Movement of the wrist towards the ulna or medial side

up/down rotation

scapula in frontal plane

lateral tilt

pelvis in frontal plane

transverse plane joint actions

- External rotation

- Internal rotation

- Supination

- Pronation

- Protraction

- Retraction

- Pelvic rotation

external rotation

turning the joint outward

- pelvis, shoulder girdle

internal rotation

turning the joint inward

- pelvis, shoulder girdle

supination

movement that turns the palm up

- forearm

pronation

movement that turns the palm down

- forearm

protraction

moving a part forward

- pelvis, shoulder girdle, scapular specific

retraction

moving a part backward

- pelvis, shoulder girdle, scapular specific

pelvic rotation

one side of the pelvis is forward of the other side

horizontal abduction

Movement of the arm or thigh in the transverse plane from an anterior position to a lateral position

horizontal adduction

Movement of the arm or thigh in the transverse plane from a lateral position to an anterior position

Yes

Can any joint action occur in any plane or multiple planes simultaneously?

Multi-Planar Movements

circumduction, opposition, foot pronation, foot supination

Circumduction

flexion, extension, abduction, adduction

Opposition

thumb, little finger

Foot Pronation

dorsiflexion, forefoot ABD, subtalar eversion

Foot Supination

plantar flexion, forefoot ADD, subtalar inversion

Kinematic Chain

System of linked rigid bodies subject to force application

Open Kinematic Chain

distal segment is free (open) to move

• More ROM and DOF

• Curls, reaching, kicking, throwing movements

- increase joint compressive forces

- increase joint congruency (increase stability)

- decrease shear forces

Closed Kinematic Chain

distal segment is stationary (closed)

• Less ROM and DOF

• Squats, push-ups

- increase joint distraction and rotational forces

- increase joint deformation (decreases stability)

- increase shear forces

Motor Skills

a function that involves specific movements ofthe muscles to perform a task

Discrete

motion with a definitive beginning & end point

- Baseball pitch, basketball free throw, tennis serve

Continuous

- cycles of motion performed repeatedly with no well-defined beginning or end

- Walking, swimming, cycling, racing

Repeated discrete

continuous motion with recovery intervals in between

- Rowing

serial

- movements that comprise a series of discrete motions

- Triple jump

Arthrology

study of joint classification, structure, and function

Open Packed Position

contact between articulating structures is minimal = ↑ ROM

Close Packed Position

maximal contact between articulating structures = ↓ ROM

Fibrous Joints

- suture

- syndesmosis

- gomphosis

suture

An interlocking line of union between bones

syndesmosis

bones connected by ligaments

gomphoses

A type of fibrous joint such as a tooth into the alveolus

Cartilaginous joints

- Synchondroses (hyaline)

- Symphyses (fibro)

Synchondroses

bones united by hyaline cartilage

Symphyses

Bones united by fibrocartilage

Synovial joint

joint cavities

- increase movement

Plane

• Irregular joint surfaces, flat or slightly curved

- Mono-axial - only permits sliding/gliding

- No movement planes

convex

curved outward

concave

curving inward

convex, concave

When a BLANK surface moves on a stationary BLANK surface, gliding occurs opposite of rolling

concave, convex

When a BLANK surface moves on a stationary BLANK surface, rolling & gliding occurs in same direction

Knee during closed-chain flexion

posterior femur roll, anterior glide

Knee during open chain flexion

posterior roll & glide

Loading

• Magnitude

• Location

• Direction

• Duration

• Frequency

• Variability

• Rate

increases

Probability of injury BLANK when loads exceed the physiological range loads exceed the physiological range

single

Injury can result from BLANK overload or overuse

(**Improper Loading Often**)

Basic Injury Mechanics

Contact & impact

Dynamic overload

Overuse

Volume, intensity, technical breakdown, nutrition deficiency, lack of recovery

Structural vulnerability

Inflexibility

Magnitude/rate of tissue deformation

Postural deficit

Muscle imbalance

Strength, length

Rapid growth

Skeletal acceleration - body ACC

Energy absorption - ability to absorb energy impact

Contributing Factors to Injury

• Age

• Gender

• Genetics

- Neuromuscular, CT

• Training status

• Nutrition

• Psychological stress

• Fatigue

• Environment

• Equipment

• Previous injury

• Disease

• Drugs

• Pain

• Experience

• Skill level

• Anthropometrics

• Rehabilitation

Rigid Body

Mechanics -> BLANK -> Dynamics -> Kinematics, Kinetics

Biomechanical Modeling

• Representation of ≥ 1 of an object/system’s characteristics

• Types:

– Physical

– Mathematical (Computer)

• Development of equations to characterize motor skills

– Hybrid

• Forward Solution Approach – measured kinetic data are used to predict kinematics

• Inverse Solution Approach (Inverse Dynamics)– measured kinematic data are used to predict kinetics