Kinesiology Block 2

Which articulation of the elbow is primarily responsible for elbow flexion and extension?

a. humeroulnar joint

Which of the following ADLs would be significantly limited by a loss of elbow flexion in the dominant upper extremity?

d. both A and C

You are working with a patient with stiffness of the forearm that significantly limits their active forearm supination. Which of the following motions would compensate for this specific loss of forearm motion?

c. shoulder adduction and external rotation

Which of the following structures provides the most medial stability to the elbow?

a. ulnar collateral ligament

The humeroulnar joint is best described as what type of articulation?

b. uniaxial hinge

For which of the following would the biceps brachii muscle be most active?

b. using a screwdriver to tighten a screw with your right hand, with the arm at the side

Which of the following would be most difficult for an individual who has a significant deficit in pronation of both forearms?

d. typing on a standard keyboard

Laxity of the medial collateral ligament (MCL) of the elbow may contribute to which of the following?

a. cubitus valgus

Prolonged repetitive elbow flexion may contribute to tension and compression on the ulnar nerve at which elbow landmark?

c. cubital tunnel

A fall on outstretched hands (FOOSH) with the elbow extended would most likely cause which of the following at the elbow?

c. posterior dislocation

acquired amputation

the surgical amputation of a limb

bony congruity

the degree of conformity of bone surfaces at a joint

carrying angle

the natural valgus angulation of the elbows that allows the arms to swing wide of the hips

cubital tunnel syndrome

a condition of chronic compression or tension on the ulnar nerve within the cubital tunnel of the elbow

cubitus valgus

angulation of the elbow positioning the forearm farther (laterally) from the body than normal

cubitus varus

angulation of the elbow positioning the forearm closer to the body (medially) than normal

cumulative trauma disorder (CTD)

a musculoskeletal pathology that involves repetitive trauma to soft tissues leading to painful inflammation and fatigue

flexion contracture

a type of joint contracture in which the joint is positioned in some degree of flexion due to restrictions of surrounding soft tissues and the passive and active extension of the joint are limited

lateral epicondylosis

degenerative tendinopathy involving the extensor muscles of the wrist and hand

medial epicondylosis

degenerative tendinopathy involving the flexor muscles of the wrist and hand

pronator teres syndrome

a condition in which the median nerve is compressed between the two heads of the pronator teres as it enters the forearm

upper limb amputation

the loss of a portion of or the entire upper extremity due to disease process, trauma, or surgical removal

Humeroulnar Joint

Uniaxial, diarthrodial, modified hinge joint

flexion/extension

Radioulnar joints

Diarthordial, uniaxial joint of pivot (trochoid) type

Rotation of forearm via supination/pronation

Lateral Collateral Ligament

Protects against varus stress

Radial side

Medial Collateral Ligament

Ulnar side

Provides stability to Ulnar side limiting valgus stress

Cubitus valgus

The forearm is excessively lateral to the humerus in the frontal plane

Carrying angle is increased beyond the average

Cubitus Varus

Deformity in which the angulation of the part is toward the midline of the body

forearm bent inward/closer to the body

Annular Ligament

Encircles the head of the radius

Maintains radial head in place

Prevents inferior displacement

What injury is associated with the annular ligament

nurse’s maid injury

annular ligament keeps elbow from dislocating

is the range of motion less or more more active flexion vs passive flexion and why

Active flexion is less than passive flexion

the bulk of the contracting flexors interferes with the forearm contacting the upper arm

Active insufficiency of triceps occurs during..

shoulder extension

Active insufficiency of the biceps occurs during..

shoulder and elbow flexion

what is the closed pack position when talking about the elbow

Full extension with the olecranon process in the olecranon fossa, and the joint capsule, medial and lateral collateral ligaments are taught

what muscles make up the elbow flexors

Brachialis

Biceps brachii

Brachioradialis

what everyday activities are affected by elbow flexors

personal hygiene, self-feeding, lifting objects, and similar functional activities

where does brachialis originate

anterior side of the lower humerus

where does brachialis insert

coronoid process of the ulna

what is the origination of biceps brachii

shorthead from coracoid of scapula and long head from supraglenoid tubercle of scapula

where does biceps bracii insert

tuberosity of radius

origin of brachioradialis

supracondylar ridge of the humerus

insertion of brachioradialis

lower end of the radius just proximal to the styloid process

what muscles make up the elbow extensors

Triceps brachii

Anconeus

what type of movements are important for elbow extensors

move the hand away from the body for open-chain movements- fishing, etc

upper body functions in closed-chain movements- patient transfers, adaptive devices

where do the triceps originate

medial and lateral heads from the humerus

long head from the infraglenoid tubercle of the scapula

insertion of triceps

olecrenon prcoess

when are triceps active during elbow flexion

during closed kinematic movements such as pushups

origin of anconeus

lateral epicondyle of the humerus

insertion of anconeus

both the olecranon process and the posterior ulna.

action of anconeus

assists in elbow extension

stabilizes during supination and pronation

Structure of Proximal Radioulnar Joint

Ulnar radial notch

Annular ligament

Capitulum of the humerus

Head of the radius

Structure of Distal Radioulnar Joint

Ulnar notch of radius

Articulation disc

Head of ulna

what is the relationship between the Proximal/Distal Radioulnar Joints

are mechanically linked.  Motion at one joint is always accompanied by motion at the other joint.

Loads from hand are carried by radioulnar joint with ____% on the radius and ____% on the ulna

80% / 20%

Pronation occurs by the radius crossing over the ________ superior at the _______________________.

ulna

proximal radioulnar joint

Pronation and supination occur around a _______ axis

longitudinal

what muscles are the primary rotators of the forearm

pronator teres

pronator quadratus

biceps brachii

supinator

which arm muscles are pronators

pronator teres

pronator quadratus

which muscles are supinators

biceps brachii

supinator

Pronator teres origniates where

medial epicondyle of the humerus

Insertion of pronator teres

lateral side of the radius

which muscle Stabilizes the proximal radioulnar joint

pronator teres

pronator quadratus originates where

the ulna

pronator quadratus inserts where

radius

which muscle Maintains compression of the distal radioulnar joint

pronator quadratus

Supinator originates where

lateral epicondyle of the humerus

lateral aspect of the ulna

Where does supinator insert

the radius

Supination action of biceps brachii

Active in resisted supination and fast supination when the elbow is flexed to 90 degrees

ADLs require elbow flexion between_____ to _____ degrees, ___ degrees of pronation and ___ degrees of supination.

30 to 130

50 , 55

common elbow fractures

Fracture of radial head by impact on capitulum

Fracture of the coronoid or olecranon process of the ulna by impact on the humerus

Fracture of the supracondylar area, if the radius and ulna absorb shock

Nursemaid’s elbow

Dislocation of the elbow

when the annular ligament slips over the head of the radius, partially dislocating the elbow joint

often occurs when caretakers quickly pull up on a child’s arms

Medial collateral ligament repetitive stress

Over time, the ligament becomes irritated, inflamed, and weakened. Micro‑tears accumulate, reducing its ability to stabilize the joint

Seen in throwing sports like baseball

Tennis elbow (lateral epicondylosis)

repetitive strain on the forearm muscles and tendons, particularly the extensor carpi radialis brevis (ECRB) tendon

often seen in tennis, typing, swimming, painting

Medial tendonitis or medial epicondylitis (golfer’s elbow)

inflammation of the flexor-pronator mass tendons (common flexor tendon) at the medial epicondyle

Repetitive wrist flexion, forearm pronation, or gripping

Cubital tunnel syndrome

ulnar nerve compressed

causing numbness, tingling, pain, and possible weakness in the ring and little fingers

Frequent elbow bending (e.g., phone use, sleeping with bent elbows); Leaning on the elbow for long periods

Radial nerve injury

damages the nerve in your upper arm that controls triceps movement, wrist/finger extension, and sensation in part of the hand, often causing pain, weakness

wrist drop (a deficit in the hand limiting extension of the wrist, digits, and/or thumb)

Median nerve injury

affect wrist and middle fingers

Repetitive flexion of the wrist

Weakness in wrist flexion, forearm pronation, and hand muscles; “hand of Benediction” when making a fist

Articulation of the humeroulnar joint

trochlea of the humerus (convex)

trochlear notch of the ulna (concave)

Humeroradial joint

Uniaxial, pivot joint

Humeroradial joint articulations

capitulum of the humerus (convex)

fovea of the radius (concave)

When the radius and ulna move in flexion and extension, are they convex-concave or opposite

Concave on convex (moving in same direction in open kinematic chain)

when the humerus moves in elbow flexion and extension, is it convex-concave or opposite

convex on concave (rolling in opposite directions)

muscles that attach to the lateral epicondyle do what 3 motions

wrist extension, finger extension, and supination

muscles that attach to the medial epicondyle do what 3 actions

wrist flexion, finger flexion, and pronation

wrist flexion/extension are in which plane/axis

sagittal with frontal

what plane/axis is radial an ulnar deviation in

frontal with sagittal axis

radiocarpal and midcarpal joints are what kind of joints

uniaxial

where is the radioulnar disc located

between the head of the ulna the lunate and triquetrum

Midcarpal Joint is made up from the articulation of…

between the scaphoid, lunate, and triquetrum proximally and the trapezium, trapezoid, capitate, and hamate distally.

radiocarpal joint is formed by articulation of…

Radius and radioulnar disc proximally and by the scaphoid, lunate, and triquetrum distally

which bone on the proximal row, does not help form the radiocarpal joint

pisiform

Independence in ADLs requires a functional motion of ____ degrees flexion and ____ degrees of extension.

10, 35

is radial/ulnar deviation easier in full extension or full flexion

flexion

what muscles make up the dorsal wrist

Extensor carpi radialis longus (ECRL)

Extensor carpi radialis brevis (ECRB) – Active during most grasp and release hand activities.

Extensor carpi ulnaris (ECU)

Extensor digitorum (ED)

Extensor indicis (EI)

what muscles make up the palmer wrist

Palmaris longus (PL)

Flexor carpi radialis (FCR)

Flexor carpi ulnaris (FCU)

Flexor digitorum superficialis (FDS)

Flexor digitorum profundus (FDP)

Flexor pollicis longus (FPL)

which muscles are involved in ulnar deviation

which muscles are involved in radial deviation

Smith’s fracture

Volar displacement of distal bone (inward)

Colles’ fracture

Dorsal displacement of distal bone (outward)

Secondary complications of smith and colles fractures

edema, scar tissue, nerve compression, unresolved joint stiffness