elbow anatomy and biomechanics
DESCRIPTION
Elbow Anatomy and Biomechanics . Mimi Renaudin, DPT University of Mississippi Medical Center. Objectives. Describe the anatomy and joint articulations at the elbow Discuss the static and dynamic constraints acting at the elbow Identify the neurovascular contributions within the elbow joint. - PowerPoint PPT PresentationTRANSCRIPT
Elbow Anatomy and Biomechanics
Mimi Renaudin, DPTUniversity of Mississippi Medical
Center
Objectives• Describe the anatomy and joint
articulations at the elbow• Discuss the static and dynamic
constraints acting at the elbow• Identify the neurovascular contributions
within the elbow joint
Elbow Snap Shot• Trochoginglymoid joint
– 2 Degrees of freedom Flexion/Extension and forearm rotation
• Humerus• Radius • Ulna
Anatomy Overview
Joint Articulations
Humeroulnar
Proximal Radioulnar
Humeroradial
Anterior Muscular Component• 9 muscles cross the anterior aspect of
the joint– Only 3 have primary action on the elbow
• Radioulnar joint - rotation• Remaining 4 muscles arise from
common flexor tendon on medial epicondyle
Elbow Flexors
Radioulnar Motion• Supinator,
pronator teres with assistance from pronator quadratus distally
Anterior Musculature• Final 4 muscles
attach on medial epicondyle
• Primary actions occur at the wrist and digits– PL– FCR– FCU– FDS
Posterior Muscular Component• Elbow extensors: triceps, anconeus
– Triceps: 3 heads Long: crosses GH and elbow Medial/Lateral: only cross elbow
– Anconeus• Common extensor tendon
Elbow Extensors
Lateral Epicondyle Attachments• Extensor carpi
radialis longus• Extensor carpi
radialis brevis• Extensor
digitorum• Extensor carpi
ulnaris• Extensor digiti
minimi
Capsuloligamentous Complex• Medial collateral ligament• Lateral collateral ligament
Medial Collateral Ligament• Resists valgus stress • Limits extension• Taut throughout arch of
motion– Anterior fibers most taut
in extension– Posterior bundle is taut
in flexion• Transverse fibers
provide valgus stability and help with joint approximation
Vascular Contribution
Normal Elbow Motion• Normal ROM:
– Elbow 0-145°– Pronation: 80°– Supination: 85°
Functional ROM:Elbow 30-130°Pronation: 50°Supination: 50°
Carrying Angle• Formed by valgus tilt of the axis of
rotation (humeral articulation) and the valgus orientation of the ulnar shaft in reference to the olecranon
References1. DeLee, Drez. DeLee and Drez’s
Orthopaedic Sports Medicine. 3rd ed. 2009.
2. Levangie PK, Norkin CC. Joint Structure & Function. 4th ed. 2005. 273-295.
3. Moore KL, Dalley AF, Agur AM. Clinically Oriented Anatomy. 6th ed. 2010. 734-762.
Questions