BIOMECHANICS OF ELBOW COMPLEX

INTRODUCTION

• The joints and muscles of the elbow complex are designed to serve the 

hand.They provide mobility for the hand in space by shortening and lengthening

the upper extremity.

• Rotation at the elbow complex provides additional mobility for the hand.

• The elbow complex structures also provide stability for skilled(or)forceful

movements of the hand when performing activities with tools or

implements.

• Many of the 16muscles that cross the elbow complex also act at either the

wrist or shoulder, and therefore the wrist and shoulder are linked with the

elbow in enhancing (increase)of the hand.

 

INTRODUCTION 

ABOUT -  HUMERO-RADIAL and HUMERO-ULNAR JOINT

• Type- Synovial joint (diarthrodial).

• Variety- Modified(or)Loose Hinge joint.

• Why it is called as modified or loose hinge joint?

-> As light bit of axial rotation and side-to-side motion of the ulna occurs during Flexion and Extension.

-> So it is not pure Hinge joint.

• Uniaxial- One degree of freedom possible at elbow, permitting the Flexion and Extension (Which occur in

sagital plane around coronal axis).

Ligaments- 2 Major ligaments

• Muscles- 5 muscles are directly associated with elbow joint. Which crosses it.

• 3 Muscles Flexors Anteriorly

• 2 Muscles Extensors 

STRUCTURE

Articulating surface on the Humerus

• Bones taking part- Distal part of

humerus.

• Anterior aspect:

->Trochlea

->Capitulum

• These structure are articulating

between the medial and lateral

epicondyle of humerus.

Trochlea:

• Which forms part of the Humero-ulnar

articulation.

• Hourglass - shape

• Location:-

->Angle on the medial aspect of distal

humerus.

->And lies slightly anterior to the humeral

shaft.

• A groove called trochlear groove.

CARRYING ANGLE:-

->The medial portion of the trochlea projects

distally more than the lateral portion and

results in a VALGUS ANGULATION of the

forearm called the carrying angle.

->Normal ;

->Male- 13 degree,

->Female-15 degree

REASON - Because of medial portion of

trochlea grows longer in a shorter

person than in a taller person.

Height of females is usually less

than men, and Wider pelvis.

• The indentation in the humerus located

just above the trochlea is called the

coronoid fossa.

• And this designed to recieve the coronoid

process of the ulna at the end of the elbow

flexion.

CAPITULUM

• Which is the part of Humeroradial

articulation.

• Spherical shaped.

• Location:

->It is the located on the anterior

lateral surface of the distal

humerus.

->It lies anterior to the shaft of the

humerus.

• A groove is called

capitulotrochlear groove

separates the capitulum from

trochlea.