kinesiology lecture 2

what is bone

Functions as a tissue (physiological organ) and anatomical structure (biomechanical organ)

what does bone do as a tissue

calcify matrix

rich in blood supply

stores and releases calcium, phosporus, magnesium, and sodium

what does bone do as a structure

support to the body

levers for muscle action

resists compression> tension> shear

What types of forces are there on tissue

compression, tension, bending, shear, torsion, combined

what types of biological tissues are there

bone, articular cartilage, fibrocartilage, tendons, ligaments, fascia, muscle

How do forces act on segments with a designated load?

move or deforms tissue

what is the hueter-volkmann law

pediatric patients

skeletally immature/ growth plates

compression= inhibits bone regrowth

tension=accelerates growth on cartilage

what is wolff’s law

skeletally mature

adult patients

compression= stronger bones

tension= accelerating osteoclasts

bone adapts and remodels

How can bone fatigue occur

few sudden large loads or many reps of small loads

What is the difference in bone by age?

younger bone = pliable and growing

older bone= rigid and loss of ability to deform

what is the stages to bone response of a force

1. type of force

2. direction of load

3. rate of load (static or dynamic)

4. frequency of load

5. distribution of load

what is articular cartilage?

distributes joint forces and reduces friction

avascular and anueral

ex: synovial joint

what is fibrocartilage

stabilizes joints, guides arthrokinematics, shock absorber

resistance to tension, shear, and compression

anueral, limited blood supply

ex: discs and labrum

what is a tendon

transfers large tension load between muscle and bone

higher amounts collagen fibers

golgi tendon proprioceptve feedback

very stiff

passive

what is a ligament

attaches bone to bone

restricts joint motion and resists tension

higher elastin fibers

poor blood supply

proprioceptive feedback

passive

what is fascia

supports surrounding connective tissue

mix of collagen and elastic fibers

passive

plantar, trunk, muscle

Is tendon or a ligament best suited to transfer muscle force to move a bone? Why?

tendon= muscle to bone , more stiffness

what is anueral

no pain receptors or nerves

where is perimysium located

around a bundle of fibers

middle layer

where is endomysium located

around an muscle fiber

internal layer

where is epimysium located

around muscle belly

external layer

what is the said principle

specific action imposed demand

what is active tissue

Length that allows the greatest number of cross

bridges, produces greatest potential force, muscle belly contracting

what is passive force

tissue stretched to create tension

ligaments, tendons, fascia, lacking contraction stiffness

what is stress

a physical load applied on an area

what is strain

the percentage change in tissue length

Motion moving with gravity is what type of muscle

contraction?

eccentric

Motion moving against gravity is what type of muscle

contraction?

concentric

what is the equation for total force on a tissue

total force = active + passive

What is the cross-bridge theory

the most corssbridges at resting length allows the most force

what is active insufficiency

inability for muscle to produce enough force to over either joint at full ROM at the same time

what is passive insufficiency

inability for a muscle to stretch enough to allow full ROM at either joint at the same time

What bi-articular muscles act at both the shoulder and the elbow?

bicep and tricep

Which muscle would be lengthened by shoulder flexion and elbow flexion?

triceps

Which muscle would be shortened by shoulder flexion and elbow flexion?

bicep

If you try to contract the over-lengthened muscle and cannot produce more force, what type of insufficiency is this?

passive

If you tr y to contract the shortened muscle and cannot produce more force, what type of insufficiency is this?

active

what is the definiton of tissue stiffness

ratio of applied stress caused by the applied strain

What is a common activity that considers changing a

tissue length and time?

stretching

what is elasticity

the length change and deformation

what is viscosity

the fluid resistance to flow

most muscles have this

what is stress/ load relaxation

the longer the load is applied the less force will be needed

what is creep response

force applied to a tissue is constant

What is the level of tension at a shortened length for active tissues and passive tissues?

active= some

passive=none

What is the level of tension at a resting (ideal) length for active tissues and passive tissues?

passive = none

sctive= max

What is the level of tension at an increased length for active tissues and passive tissues?

active= none

passive=max

what is a motor unit

a single alpha motor neuron and the motor fibers it innervates

what is recruitment

the number of motor units activated

what is rate coding

how fast neuron signals are being sent