The Elbow

Specific Readings:
Behnke: pgs. 64-75
Thompson and Floyd: pgs. 103-123

Bony Articulations

• Humeroulnar Articulation

• Humeroradial Articulation

Stability of Elbow

 

Collateral Ligaments

1. Radial Collateral Ligament

2. Ulnar Collateral Ligament – Anterior and Posterior Bands

 

Radioulnar Joint

Pivot type joint that produce pronation and supination of the forearm

1.      Anular Ligament (Radioulnar Joint)

• For radioulnar joint to be stable:

Stabilizers

Restraining Force During Displacement

Position	Stabilizing Element	Distraction	Varus	Valgus
Extension	MCL	12	-	31
	LCL	10	14	-
	Capsule	70	32	38
	Articulation	-	55	51
Flexion	MCL	78	-	54
	LCL	10	9	-
	Capsule	8	13	10
	Articulation	-	75	33

3 Types of Forces:

1. Distraction 

2.      Varus         

3. Valgus       

Muscles of the Elbow in order of function:

• Elbow Flexors

1. Brachialis -
2. Biceps Brachii -
3. Brachioradialis
4. Extensor Carpi Brachialis

 

• Elbow Extensors

1. Medial head of Triceps Brachii -
2. Flexor Carpi Ulnaris
3. Anconeus -

• Pronation

1. Pronator Quadratus
2. Pronator Teres – Mostly active during rapid pronation or pronation against resistance.
3. Brachioradialis

• Supination

1. Supinator
2. Brachioradialis

Innervation

3 Main Nerves:

• Musculocutaneous Nerve
• Radial Nerve and
• Median Nerve

Innervation by Nerve:

C6                                           C7                                           C8

All except:                              Triceps Brachii                      Pronator Quadratus

Pronator Quadratus              Anconeus

                                                Pronator Teres