Kinesiology Laboratory 3:

Mechanical Considerations during Qualitative Analysis of Movement

Presentations Lever Class Review Activity Analysis

◦ Push up◦ Bench press

PNF Techniques

Today’s Activities

Take good notes, especially for those you are unsure of

These activities will be on the Midterm Practical!

Presentations

Movement occurs around joints◦ Flex, abduct, upwardly rotate, etc.

Movement also occurs on a single plane, about a single axis◦ Ex. Frontal

These movements are caused by muscle contractions◦ Concentric/Eccentric/Isometric

These movements can occur against a resistance◦ Gravity, body weight, resistive equipment

How our bodies produce movement

Lever Classes*Load=Resistance*Fulcrum= Pivot Point= Axis

ARE

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]

1st Class Lever

◦ 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

2nd Class Lever

◦ 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

3rd Class Lever

Chart breaking down the movement by joint FOR BOTH PHASES◦ 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)

Diagram of movement (up phase/down phase)◦ Use arrows for gravities effect

Diagram of a single joint◦ Identify muscle group and Contraction Type ◦ Identify the type of lever◦ Label the Axis, Effort and Resistance

Activity Analysis: Push Up/Bench Press

Techniques to Increase ROM at a tight muscle

Commonly used on Hamstrings◦ Why is hamstring flexibility a problem in modern

society? Two principles

◦ Golgi-Tendon Organ (GTO) Firing◦ Reciprocal Inhibition

Proprioceptive Neuromuscular Facilitation (PNF) Stretching

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)

Golgi Tendon Organs

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

Reciprocal Inhibition

Hold- Relax Contract-Relax Agonist Contraction Hold-Relax with Agonist Contraction These techniques are often combined

clinically

Proprioceptive Neuromuscular Facilitation (PNF) Stretching

Flex subjects hip to end of ROM◦ Take measurement with Goniometer

Have subject isometrically contract hamstrings (antagonist to hip flexion) for 6 seconds◦ Use verbal cues, “Push against my hands”, etc.

Tell subject to relax hamstring Flex subjects hip further and hold for 10-30

seconds◦ Take second Goniometer measurement

Hold-Relax

Flex subjects hip to end of ROM◦ Take measurement with Goniometer

Have subject isometrically contract hamstrings (antagonist to hip flexion) for 6 seconds◦ Use verbal cues, “Push against my hands”, etc.

Tell subject to relax hamstring Have subject concentrically contract

quadriceps to flex hip and hold for 10-30 seconds◦ Take second Goniometer measurement

Contract-Relax

Have subject concentrically contract quadriceps to flex hip to end of ROM◦ Take measurement with Goniometer

Have subject isometrically contract hamstrings (antagonist to hip flexion) for 6 seconds◦ Use verbal cues, “Push against my hands”, etc.

Tell subject to relax hamstring Have subject concentrically contract

quadriceps to flex hip and hold for 10-30 seconds◦ Take second Goniometer measurement

Agonist Contraction

Have subject concentrically contract quadriceps to flex hip to end of ROM◦ Take measurement with Goniometer

Have subject isometrically contract hamstrings (antagonist to hip flexion) for 6 seconds◦ Use verbal cues, “Push against my hands”, etc.

Tell subject to relax hamstring Flex subjects hip further and hold for 10-30

seconds◦ Take second Goniometer measurement

Hold-Relax with Agonist Contraction

Lab Report 3 Readings: H&K: Ch5 cont’d. ,TG: 149-166

For Next Week