Biomechanics Exam 2

Synarthroses

Immovable joints found only in the skull, forming around the age of 1.

Syndesmoses

A type of joint where fibrous tissue binds bones together, exemplified by the mid-radioulnar joint.

Amphiarthroses

Slightly movable joints, including synchondroses and symphyses.

Synchondroses

Joints where articulating bones are joined by a thin layer of hyaline cartilage, such as sternocostal joints.

Symphyses

Joints characterized by a hyaline cartilage disc, like the pubic symphysis.

Diarthroses

Freely movable joints characterized by articular cartilage, articular capsule, and synovial fluid.

Articular cartilage

Dense white connective tissue covering articulating bone surfaces, providing protection and lubrication.

Articular capsule

A double-layered membrane surrounding a joint.

Synovial fluid

A clear liquid providing lubrication inside the articular capsule of diarthroses.

Associated Bursae

Small capsules filled with synovial fluid that cushion structures in joints.

Knee

An example of a synovial joint with a ligamentous capsule and articular cavity.

Types of diarthroses/synovial joints

Gliding, hinge, pivot, condyloid, saddle, and ball and socket joints.

Ball and socket joint

A type of joint exemplified by the hip and shoulder.

Condyloid joint

A joint type represented by the knuckles.

Pivot joint

A joint type exemplified by the axis and atlas (head and neck).

Saddle joint

A joint type represented by the thumb.

Hinge joint

A joint type exemplified by the elbow and knees.

Articular fibrocartilage

Soft-tissue discs that distribute loads and improve fit between articulating bones. It limits the slip between articulating bones, protects the joint periphery, lubricates the joint, and absorbs the shock at the joint

Tendons

Connective tissues that connect muscles to bones.

Ligaments

Connective tissues that connect bones to other bones.

Joint stability

The ability of a joint to resist abnormal displacement of articulating bones or joint displacement.

Factors increasing joint stability

Close matching of bone surfaces, strong ligaments and tendons, and absence of muscle fatigue.

Joint flexibility

The range of motion allowed at a joint in different directions.

Range of motion

The angle through which a joint moves from anatomical position to the extreme limit of segment motion in a particular direction

Synarthroses

this joint has a very slight amount of movement. This includes syndesmoses like the mid-radioulnar joint where the fibrous tissue binds the bones together

Articular Cartilage

A dense white connective tissue that coats the end of bones articulating at diarthrodial joints and spread load over a wide area reducing contact stress. It provides a protective lubrication that minimizes friction and mechanical wear at the joint.

Insertion Point

the point in which movement occurs

Origin Point

The point when movement begins

Golgi Tendon Organs

organs that inhibit and increase tension in muscles, and initiate tension development in antagonists. These are located near the muscle tendon junction in series with muscle fibers. They promote overall stretch in muscles being stretched.

Muscle Spindles

Provoke reflex contraction in stretched muscle and inhibit tension in antagonists. They are interspersed among muscle fibers in parallel with the fiber and increase in muscle length

Active stretching

produced by active development of tension in the antagonist muscles. you are stretching alone.

Passive Stretching

Produced by a force other than tension in the antagonist muscles. Someone else is stretching you.

Ballistic Stretching

A series of quick, bouncing type of stretches

Static stretching

maintaining a slow, controlled, sustained stretch over time. Usually lasts about 30 seconds

Proprioceptive neuromuscular facilitation (PNF)

a group of stretching procedures involving alternating contraction and relaxation of the muscles being stretched. Requires the assistance of a partner.

Osteoarthritis

A common degenerative disease of articular cartilage in which the symptoms include pain, swelling, restriction of ROM, and stiffness. The cause is unknown and both too. much and too little mechanical stress can promote the development of it.

Subluxation

an injury where the body resets itself on its own

Dislocation

an injury where it needs to be reset by someone else.

Tissue Proximity

Concentric

Muscle is shortened (a positive muscle contraction).

Eccentric

Muscle is lengthened or stretched (a negative muscle contraction).

Isometric

No change in the length of the muscle.

Isotonic

Both shortening and lengthening are occurring (e.g., bicep curl).

Isokinetic

Both shortening and lengthening occur, but the resistance stays the same.

Agonist

Muscle that works to cause a movement.

Antagonist

Muscle that acts to slow or stop a movement.

Stabilizer

Secondary muscle that stabilizes against the force.

Neutralizer

Muscle that eliminates unwanted motion.

Active insufficiency

Condition when a two-joint muscle cannot shorten enough for full range of motion at both joints simultaneously.

Passive insufficiency

Inability of a two-joint muscle to stretch enough for full range of motion at both joints simultaneously.

Muscular strength

Measured by the amount of torque a muscle group can generate at a joint.

Torque (Tm)

Product of muscle force (Fm) and muscle moment arm (d) at the joint center of rotation.

Factors affecting muscular strength

Muscle cross-sectional area, training state of muscle, moment arms, distance, and angles.

Muscular power

Product of muscular force and the velocity of muscle shortening.

Muscular endurance

Ability of muscle to exert tension over time; opposite of muscle fatigue.

Importance of warmups

Excites nerves and muscles, making them more effective before workouts.

Sternoclavicular joint

Modified ball and socket joint between the proximal clavicle and the manubrium of the sternum.

Acromioclavicular joint

Irregular joint between the acromion process of the scapula and the distal clavicle.

Coracoclavicular joint

Syndesmosis with the coracoid process of the scapula bound to the inferior clavicle by the coracoclavicular ligament.

Glenohumeral joint

Ball and socket joint in which the head of the humerus articulates with the glenoid fossa of the scapula. aka shoulder joint

Scapulothoracic joint

Articulation between the anterior scapula and the thoracic wall.

Rotator cuff

Composed of the supraspinatus, infraspinatus, teres minor, and subscapularis (SITS).

Scapulohumeral rhythm

Regular pattern of scapular rotation that accompanies and facilitates humeral abduction.

Major flexor muscles at the glenohumeral joint

Clavicular pectoralis major and anterior deltoid, with assistance from coracobrachialis and short head of biceps brachii.

Major extensor muscles at the glenohumeral joint

Sternal pectoralis major, latissimus dorsi, and teres major, with assistance from long head of triceps brachii and posterior deltoid.

Abductor Muscles at the glenohumeral Joint

Muscles that move the arm away from the body, primarily the latissimusndorsi, teres major, and sternocostal pectoralis

Adductor Muscles

Muscles that move the arm towards the body at the glenohumeral joint, including latissimus dorsi, teres major, and sternocostal pectoralis, with assistance from biceps brachii and triceps brachii.

Medial Rotator Muscles of the humerus

Muscles that rotate inward, including subscapularis and teres major

Lateral Rotator Muscles of the humerous

Muscles that rotate outward, primarily infraspinatus and teres minor

Horizontal Adductor Muscles of the humerous

Muscles that move the arm horizontally towards the body, including pectoralis major, anterior deltoid, and coracobrachialis. Also include the infraspinatus, middle and posterior deltoid, and teres minor

Horizontal Abductor Muscles

Muscles that move the arm horizontally away from the body, including infraspinatus, middle and posterior deltoid, and teres minor, assisted by teres major and latissimus dorsi.

Humeroulnar Joint

Hinge joint where the humeral trochlea articulates with the trochlear fossa of the ulna; considered the elbow joint.

Humeroradial Joint

Gliding joint where the capitellum of the humerus articulates with the proximal end of the radius.

Radioulnar Joint

Pivot joints at the proximal and distal ends; the middle radioulnar joint is a syndesmosis.

Flexor Muscles at the Elbow

Muscles responsible for flexion, including brachialis, biceps brachii, and brachioradialis.

Extensor Muscle at the Elbow

Muscle responsible for extension, primarily the triceps brachii, assisted by anconeus.

the Forearm

Muscle responsible for pronation, specifically the pronator quadratus;

Radiocarpal Joints

Condyloid articulations between the radius and three carpal bones, forming the wrist.

Function of Retinacula at the Wrist

Fibrous bands of fascia that create protective passageways for tendons, nerves, and blood vessels.

Flexor Muscles at the Wrist

Muscles responsible for wrist flexion, including flexor carpi radialis, flexor carpi ulnaris, palmaris longus, flexor digitorum superficialis, and flexor digitorum profundus.

pronation

Pour the soup down

supination

hold the soup up

The flexor muscles at the wrist

the flexor carpi radialis, flexor carpi ulnaris, and palmaris longus

The extensor muscles at the wrist

extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris

Joints between the carpal bones of the wrist and the metacarpal bones of the hands.

what are the carpometacarpal joints?

The carpometacarpal joint of the thumb is a saddle joint. The other carpometacarpal joints are gliding joints.

The carpometacarpal joint of the thumb is a _______ joint. The other carpometacarpal joints are _______ joints.

Intermetacarpal Joints

Irregular joints between the metacarpals and the carpometacarpals

Metacarpophalangeal joints

Condyloid joints between the rounded distal heads of the metacarpals and the concave proximal ends of the phalanges these joints form the knuckles of the hand

interphalangeal joints

The proximal and distal interphalangeal joints of the fingers and the single interphalangeal joint of the thumb are all hinge joints.

Flexion, Extension, ABduction, Adduction, and Circumduction

What motions are permitted at metacarpophalangeal joints 2-5?

Hip Joint

A Ball and socket joint where the head of the femur articulates with the concave acetabulum. The integrity is enhanced by the strong ligaments crossing the joint.

Hip joint

the _____ joint is more stable than the shoulder because of the bone structure and number and strength of the muscles and ligaments crossing the joint.

The pelvic girdle

The_______ includes the two ilia and the sacrum. It can be rotated forward, backward, and laterally to optimize positioning of the hip.

Flexor muscles at the hip are iliacus and psoas major, assisted by pectineus, rectus femoris, sartorius, and tensor fascia latae

____ muscles at the hip are iliacus and psoas major, assisted by pectineus, rectus femoris, sartorius, and tensor fascia latae

Extensor

_____muscles at the hip are gluteus maximus and the hamstrings: biceps femoris, semimembranosus, and  semitendinosus.

The abductor muscle

The_______ muscle at the hip is the gluteus medius, assisted by gluteus minimus.

The adductor muscles

The ______muscles at the hip are adductor magnus, adductor longus, and adductor brevis, assisted by gracilis.