Kinesiology Final RoR 4,5,6

What is an EMG and what does it measure?

An EMG is also known as an Electromyography

an EMG measures contraction and relaxation patterns as well as the amount of muscle activity

What is an isometric contraction?

the muscle produces force but there is no change

What is a Concentric contraction?

shortening of the muscle

What is an eccentric contraction?

lengthening of the muscle

Predicting muscle function is possible when what happens?

- The proximal attachment is stabilized

- The distal attachment moves toward the proximal attachment

-The distal segment moves against gravity or resistance

- The muscle acts alon

What is Viscosity?

The resistance to an external force that causes a permanent deformation

What is Elasticity?

The ability to succumb to an elongating force and then go back to a normal length when the force is released

What is Viscoelastic?

The ability to resist changing its shape when a force is applied, but if the force is strong enough to cause change it may not return to original shape

What is Low Load Prolonged Stretch (CREEP)?

The elongation of tissue from the application of a low level load over time

What does the stress/strain curve tell us?

It tells us basically that all natural or man-made structures have their own relationship between stress and strain

Muscles arranged in a series are what?

Longer, used for mobility

Muscles arranged in a parallel are what?

Shorter, used for stability

What is cross sectional area and how does it relate to muscle strength?

It’s how we measure muscle strength and larger CSA shows more ability to generate force

How else can we measure muscle strength in the clinic?

Circumferential measures, hypertrophy, and atrophy of muscles

When muscle fibers are arranged in a “pennate” fashion: what does that do for the force of that muscle?

The muscle fibers arranged in a “pennate” produce greater force

If you are trying to build strength: should you instruct the client to do repetitions faster or slower? Why?

Slower reps because it requires longer time under tension which breaks the muscle down more and builds it back up more

What happens with Passive Insufficiency?

The muscle becomes elongated over two joints simultaneously, it prevents shortening in the opposite muscle

What happens with Active Insufficiency?

Muscle at its shortest length when its ability to produce physiologic force is minimal

What is the most efficient type of muscle contraction? Explain why

Eccentric muscle contractions are the most efficient because it requires fewer motor units and less oxygen

What does DOMS stand for and when does it occur?

Delayed Onset Muscle Shortness and it occurs when exercise is induced and there is damage at the sarcomere level of the muscle

What are the 4 shoulder joints?

Sternoclavicular

Acromioclavicular

Scapulothoracic

Glenohumeral

What are the three main bones of the shoulder?

- Humerus

- Clavicle

-Scapula

Which joint connects the upper extremity to the rest of the skeleton?

Sternoclavicular Joint

What are the 5 functions of the scapulothoracic joint?

1. Increases the ROM of the shoulder

2. Maintaining favorable length-tension relation ships for the deltoid muscle to function above 90° of glenohumeral elevation to allow better shoul der joint stability throughout a greater motion

3. Providing glenohumeral stability through main tained glenoid and humeral head alignment for work in the overhead position

4. Providing for injury prevention through shock absorption of forces applied to the outstretched arm

5. Permitting elevation of the body in activities such as walking with crutches or performing seated push-ups during transfers by persons with a disability

What kind of joint is the glenohumeral joint and how many degrees of freedom does it have?

Ball-and-socket joint

three degrees of freedom

What is the “roof” of the shoulder?

The Acromion

Explain how subacromial impingement syndrome happens?

-The deltoid overpowers the rotator cuff to pull the humeral head into the superior aspect of the glenoid socket

- the scapula shrugs upward rather than rotating upward

What are the OSTEOkinematic motions of the glenohumeral joint?

Abduction/Adduction frontal (Full Abduction)

Flexion/Extension (Full flexion)

Medial/Lateral rotation

(90 degrees of abduction= 160 degrees of rotation present)

What are the end feels of the glenohumeral joint?

All Firm

What is the closed packed position of the glenohumeral joint?

Full abduction and lateral rotation

What is the resting position of the glenohumeral joint?

20- 30 degrees of horizontal abduction, 55 degrees flexion

How does the Scapulohumeral rhythm work?

The scapulohumeral rhythm is a ratio between the glenohumeral joint and the scapulothoracic joint where for every 3 degrees of shoulder elevation there is 2 degrees at the glenohumeral and 1 at the scapulothoracic

What are the “SITS” muscles of the rotator cuff?

Supraspinatus

Infraspinatus

Triceps Brachii

Subscapularis

What dynamic shoulder stabilizer muscle has “low level activity” even at rest?

Local Stabilizers

Explain the “force couple” of the deltoid and the rotator cuff?

The deltoid and rotator cuff work together to stabilize and move the humeral head

The elbow has how many joints in one joint capsule?

Three synovial joints

Name all 3 elbow joints?

-radioulnar

-humeroradial

-humeroulnar

Which of the elbow bones is the MOST IMPORTANT related to flexion extension: the radius or the ulna?

The Ulna

Where does the elbow get it’s stability?

- bony geometry

-ligamentous support

What kind of joint is the humeroulnar joint?

a hinge joint

What is the carrying angle?

Combination of Glenohumeral joint lateral rotation, elbow extension, and forearm supination

What is the normal ROM for the elbow extension to flexion?

0-145 degrees for elbow extension to flexion

What are the end feels for elbow extension and elbow flexion?

Extension- bony, hard

Flexion- usually soft tissue

What is the closed pack position for the humeroulnar joint?

Full Extension (close packed position for humeroulnar joint)

What are the “resting positions” aka open pack positions for the humeroulnar joint?

70 degrees flexion, 10 degrees supination

What structures need SUFFICIENT LENGTH in order to allow full FLEXION at the elbow?

Posterior capsule, posterior fibers of medial collateral ligament (MCL), ulnar nerve, and elbow extensors

What structures need SUFFICIENT LENGTH in order to allow full EXTENSION at the elbow?

anterior capsule, anterior fibers of MCL, elbow flexors

What are the arthrokinematics (convex/concave rule) of the humeroulnar joint when the ULNA moves on the HUMERUS?

Concave (ulnar trochlear notch) on Convex (humeral trochlear)

What are the arthrokinematics (convex/concave rule) of the humeroradial joint when the Radius moves on the Humerus?

Concave (proximal radius) on convex(capitulum)

Is the radial head CLOSER to the humerus when the elbow is EXTENDED or FLEXED?

radial head is closer to humerus when FLEXED

What is the purpose of the olecranon bursa?

Absorbs force and reduces shock

How many degrees of freedom does the forearm have?

One Degree of Freedom

What plane does pronation/supination of the forearm take place in?

Transverse plane for forearm supination/pronation

Name two of the stabilizers of the proximal radioulnar joint?

Lateral Collateral Ligament (LCL)

Oblique Cord

Name two of the stabilizers of the distal radioulnar joint?

Articular Disc

Triangular Fibrocartilage Complex

Which muscle is the primary flexor of the elbow?

Brachialis

Which muscle is our primary supinator?

Biceps Brachii

Which muscle INITIATES elbow extension?

Triceps Brachii

Explain the syngergistic muscle action of the bi/triceps when opening a doorknob?

-The triceps stabilize the elbow and prevent elbow flexion as the forearm supinates

-affected by the demands of the task, force required, direction of load, type of contraction

Why does our body recruit “one joint muscles” first??

-Active insufficiency can occur with multi-joint muscles

-We don’t want our muscles to get fatigue