Lecture 21 Flashcards
What is the movement of the elbow and hand relative to?
elbow- relative to arm at elbow
hand - relative to forearm at wrist
What are the intrinsic movements of the forearm?
Rotatory
-radius move medially over ulna for pronation
-radius moves laterally for supernation
Pivots = proximal and distal Radio-ulna Joints
Hinge = interosseus membrane
What is the movement of the hand?
rotated almost 360 degrees around the long axis of the limb
What muscles function in the rotatory movements in the arm?
- Pronator Teres (PT)
- Pronator Quadratus (PQ)
- Supernator
What is the exception to the forearm containing just a bulk of muscles that control the hand ?
Brachioradialis
- Inserts on Distal Radius
- Elbow Flexor
What 3x things separate the anterior flexor compartment and posterior extensor compartment in the forearm?
- Interosseus membrane
- M.I.S. Medial Intermuscular Septae
- L. I. S. Lateral Intermuscular Septae
When are the compartments of the forearm symmetrical?
at distal end
What are the 5x groups of movements created by the forearm muscles?
- Extension/Flexion of elbow
- Extension/Flexion at wrist
- Extension/Flexion at digits
- Adduction/Abduction at wrist
- Supernation/Pronation of hand
20 muscles
What starts earlier out of ulna or radius?
Ulna - has Olecranon
What are the 3x functions of the humerus and forearm and elbow?
- Distance hand from body
- Move hand
- Apply force to environment
Is it he broad triangular cross section or the round head which generates the most strength?
broad triangular base of ulna
- where most of the strength comes from in the Ulna
- Reciprocal b/w distal and proximal ends
Distally what does the round head of the Ulna help with?
Pronation and Supernation
Out of the radius and Ulna, which articulates with the wrist joint proper?
Radius’ broad articulating surface (Triangle)
-ulna doesnt articulate at wrist joint, as is barred by the TFC/Triangular Fibrocartilage Complex/Fibrous Articular Disc
Where are your strong collateral ligaments of your wrist located from?
Strong styloid processes
-sides of ends of bone
What are the 4x components of the Distal Radio-Ulna Joint?
- Ulna Notch (in radius, named by what is filling it)
- TFC/Triangular Fibrocartilage complex/ FAD Fibrous Articular Disc
- Head of Ulna
- Ulnar Styloid process
Does the ulna rotate at all?
Not AT ALL
-radius rotates over ulna allowing supernation and pronation
What si the sacciform recess?
Budlging of the synovial membrane between radius and ulna
Due to alot of movement in the wrist joint
Anular ligament
wraps around proximal radius
holds Proximal radius in place
so just rotates -doesnt roll over ulna like distal joint
-keeps the 2x bones together
What sort of movements does the ulna do?
Nothing much
No rotation
only a little bit of abduction/adduction
What are the 3x function of Interosseus membrane?
- Hinge: flexibe hinge. holds radius in relation to ulna (for most of its length) during pronation and supernation -soft to occur - cannot just rely on anular ligament and TFC.
- Muscle Attachment
- Force transmission. Most force transmitted up to small proximal circular head of radius.1. Radius moves up. 2. Oblique fibres placed unfer tension. 3. Force transmitted down into broad stronger base of ulna at same Proximal end
What is the triangular ligament?
FAD - fibrous articular disc
TFC -triangular fibrous complex
What forms the true wrist?
carpals