Functional anatomy forearm

PRU joint supination roll, glide

Mainly spinning motion within the annular ligament, but some roll, glide. Convex radial head rolls posterior and glides anteriorly on the concave radial notch of the ulna

PRU joint pronation roll, glide

Mainly spinning within the annular ligament, but some roll,glide, Convex radial head rolls anterior and glides posterior on the concave radial notch of the ulna

The _____ sustains most of the compressive forces with muscle contraction. This is because most of the elbow flexors, pronators and supinators attach on the radius and pull the radius proximally with contraction causing compression at the _______ joint. The interosseous membrane the transfers a part of the muscle force applied to radius onto the ulna

radius, Humero-radial

PRU bony stabilizer: At the end range pronation the shaft of the _____ contacts the ____ and limits further pronation

radius, ulna

Oblique Cord fibers are at ____ angles from the interosseous membrane. Resist _______ forces. May assist in preventing separation of the radius from the ulna

right, distraction

The interosseous membrane is ______ by distally applied forces to the radius. necessitate stability from other less capable structures and _________

slackened, brachioradialis

___ degrees of supination is possible at the forearm. ___ degrees is necessary for most daily activities. Prime movers: At end range supination the radius and ulna are parallel. End feel is ____ due to ligament stretch.

90, 50 Biceps brachii, supinator firm

PRU Ligaments

Annular ligament, Quadrate ligament, Oblique cord

Supinators _______ provides most of the torque during supination while the supinator is used for _________ tasks.

Biceps, low powered

Reverse action In a _____ situation the humerus/ulna externally rotate on the fixed radius causing a relative pronation of the forearm. This is a reverse action of the pronators. WB pronation is produced by the _______ of GH, ER. Opposite occurs during supination

CKC, force couple

If patient has trouble supinating they will compensate with

Glenohumeral external rotation

Capsule stabilizer PRU The elbow capsule encloses the _________ joint, ______ joint, and ______ joint

Humero-ulnar, humero-radial, proximal radio-ulnar

Pronation prime movers: the radius rotates on a relatively fixed ulna. At end range pronation, the distal radius has crossed over the ulna. End feel is _____ because of bone to bone contact of the radius on the ulna

Pronator Quadratus, Pronator Teres hard

Pronators ____________ is active during high power pronation actions compared to _______ which is active during all pronation movements including high and low powered tasks. The pronator quadratus also stabilizes the ________ joint

Pronator teres, Pronator quadratus, DRU

DRU joint pronation roll, glide

The concave distal radius rolls and glides anteriorly on the convex head of the ulna

DRU joint supination roll, glide

The concave distal radius rolls and glides posteriorly on the convex head of the ulna

Stabilizing structures of DRU joint

Triangular fibrocartiliage complex capsule Tendon of extensor carpi ulnaris Pronator quadratus Interosseous membrane Anterior and posterior radio-ulnar capsular ligaments

Annular ligament fits snugly around the radial head holds the proximal radius against the ulna and resists ______ forces

distraction

With weight bearing the ______________ allows part of the compressive force to be transferred from the radius to the ulna. This allows for a more ______ share of the compressive force

interosseous membrane, equal

If a patient has trouble pronating they may compensate by

medially/internally rotating the shoulder

Interosseous membrane fibers run ______ medially and distally from _______ to ______. Binds the radius to the ulna. It has a role of _______ force transmission. Serves as an attachment for several extrinsic hand muscles

obliquely, radius, ulna, compressive

PRU Pronation is the movement of turning the ______ down toward the floor. ____ degrees is available at the forearm. While _____ degrees is needed for most daily activities.

palm, 75, 50

Proximal Radio-Ulnar joint is a synovial, uniaxial ________ joint. The _____ rim of the head of the radius articulates with the concave radial notch of the ulna. Closed Packed position is at maximum ________ or ________. Resting position is ______ degrees supination with _____ degrees elbow flexion.

pivot, convex, supination, pronation. 35, 70

Main motion occurring at the DRU joint is _______ and _______. Movement of the DRU joint is __________ of the movement of at the PRU joint. Axis of motion runs longitudinally from the _________ to the ________

supination, pronation, interdependent, radial head, ulnar head

The main motion at PRU joint is ________/________. The axis of motion runs _________ from the redial head to the ulnar head. Muscle must lie on _______ side of the axis of rotation.

supination, pronation. longitudinally, either

Quadrate ligament

supports the proximal RU joint

When biceps is used to supinate the _____ must be activated to counteract flexion action of the biceps at the elbow and ________ at the shoulder

triceps, posterior deltoid

Triangular fibrocartilage complex (TFCC) occupies most space between ______ and ______ bones on the ulnar side. It is the _________ stabilizer of the DRU joint. Includes the ________ and ________ such as the Ulnar collateral ligament

ulna, carpal, primary, articular disc, ligaments

DRU joint is a synovial, _____ axil _____ joint. The convex head of the ______ articulates with the _______ ulnar notch of the distal radius and the _________. Closed packed position is at max pronation or supination. Resting position is ____ degrees supination

uni, pivot, ulna, concave, articular disc, 10