Mechanical Considerations during Qualitative
Analysis of Movement
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Presentations
Lever Class Review
Activity Analysis
◦ Push up
◦ Bench press
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PNF Techniques
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Take good notes, especially for those you are
unsure of
These activities will be on the Midterm
Practical!
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Movement occurs around joints
◦ Flex, abduct, upwardly rotate, etc.
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Movement also occurs on a single plane,
about a single axis
◦ Ex. Frontal
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These movements are caused by muscle
contractions
◦ Concentric/Eccentric/Isometric
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These movements can occur against a
resistance
◦ Gravity, body weight, resistive equipment
*Load=Resistance
*Fulcrum= Pivot Point= Axis
A
R
E
xis
esistance
ffort
◦ Seesaw
◦ Where the axis is determines the mechanical
advantage
 Axis close to effort results in greater speed and ROM
 Axis close to resistance results in greater force
production
◦ Elbow Extension
 Effort= Olecranon Process (Insertion of Triceps)
 Axis= Elbow Joint
 Resistance= Forearm [+/- additional weight]
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Wheelbarrow
Produces largest force production but has less ROM
Very few examples exist in the body
Plantar Flexion
 Effort= Calcaneous through Achilles tendon (insertion
of calf muscles)
 Resistance= Whole body (+/- added weight)
 Axis= Ankle Joint
◦ Tongs
◦ Elbow Flexion
 Axis= Elbow Joint
 Effort= Insertion of Biceps Brachii
 Resistance= Forearm (+/- added weight)
◦ This lever has the advantage of higher speed and
greater ROM
◦ Most common lever in the human body
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Chart breaking down the movement by joint FOR
BOTH PHASES
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Osteokinematic motion (Flex, adduct, etc.)
Muscle Functional Group (i.e. Wrist Flexors)
Agonist & Synergists
Contraction Type
Planes and axes
Effects of gravity (Resisting, Assisting, No effect)
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Diagram of movement (up phase/down phase)
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Diagram of a single joint
◦ Use arrows for gravities effect
◦ Identify muscle group and Contraction Type
◦ Identify the type of lever
◦ Label the Axis, Effort and Resistance
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Techniques to Increase ROM at a tight muscle
Commonly used on Hamstrings
◦ Why is hamstring flexibility a problem in modern
society?
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Two principles
◦ Golgi-Tendon Organ (GTO) Firing
◦ Reciprocal Inhibition
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The GTO are receptors of the tendons of
skeletal muscle
They detect changes in tension along the
muscle fibers
They relay this information to the spinal cord
and brain
When muscle tension is too great, the GTO
send inhibitory impulses, causing the muscle
to relax (stop contracting)
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Impulses that cause an antagonist muscle to
relax (decrease tension) in order for agonist
muscle to contract
Occurs on opposite “sides” of joint in
sequence
“Pulled Hamstring” occurs when reciprocal
inhibition backfires and quads and hams are
contracted at the same time
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Hold- Relax
Contract-Relax
Agonist Contraction
Hold-Relax with Agonist Contraction
These techniques are often combined
clinically
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Flex subjects hip to end of ROM
◦ Take measurement with Goniometer
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Have subject isometrically contract
hamstrings (antagonist to hip flexion) for 6
seconds
◦ Use verbal cues, “Push against my hands”, etc.
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Tell subject to relax hamstring
Flex subjects hip further and hold for 10-30
seconds
◦ Take second Goniometer measurement
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Flex subjects hip to end of ROM
◦ Take measurement with Goniometer
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Have subject isometrically contract
hamstrings (antagonist to hip flexion) for 6
seconds
◦ Use verbal cues, “Push against my hands”, etc.
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Tell subject to relax hamstring
Have subject concentrically contract
quadriceps to flex hip and hold for 10-30
seconds
◦ Take second Goniometer measurement
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Have subject concentrically contract quadriceps
to flex hip to end of ROM
◦ Take measurement with Goniometer
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Have subject isometrically contract hamstrings
(antagonist to hip flexion) for 6 seconds
◦ Use verbal cues, “Push against my hands”, etc.
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Tell subject to relax hamstring
Have subject concentrically contract quadriceps
to flex hip and hold for 10-30 seconds
◦ Take second Goniometer measurement
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Have subject concentrically contract
quadriceps to flex hip to end of ROM
◦ Take measurement with Goniometer
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Have subject isometrically contract
hamstrings (antagonist to hip flexion) for 6
seconds
◦ Use verbal cues, “Push against my hands”, etc.
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Tell subject to relax hamstring
Flex subjects hip further and hold for 10-30
seconds
◦ Take second Goniometer measurement
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Lab Report 3
Readings: H&K: Ch5 cont’d. ,TG: 149-166