BIOMECHANICS OF ELBOW COMPLEX
U.RADHAKRISHNAN.M.P.T
INTRODUCTION
 Elbow complex is designed to serve hand.
 They provide MOBILITY for Hand in space by
apparent shortening and Lengthening of upper
extremity.
 They provide Stability for skillful and forceful
movements
ELBOW JOINT
HUMERO ULNAR JOINT
 ARTICULATIONS OF HUMEROULNAR JOINT
 The articulating surface on the Humerus is Hour glass
shaped TROCHLEA
 The articulating surface on Ulna is a semicircular shaped
concave surface called TROCHLEAR NOTCH
HUMERO RADIAL JOINT
 ARTICULATION OF HUMERORADIAL JOINT
 The articulating surface on the Humerus is spherical –
shaped CAPITULUM
 The articulating surface on the RADIUS is the cup shaped
Radial head surrounded by a rim
ARTICULATIONS OF JOINT
 IN EXTENSION
 The OLECRANON PROCESS enter the olecranon fossa in
Humeroulnar Joint
 There is no contact between the articulating surfaces in
Humeroradial Joint.
ARTICULATIONS OF JOINT
 IN FLEXION
 The Trochlear ridge of Ulna slides along the Trochlear groove
until the Coronoid process reaches the Coronoid fossa in
Humeroulnar joint
 The radial head slides over capitulum and reaches Radial
fossa in Full Flexion.
JOINT CAPSULE
 The Humeroulnar , Humeroradial and Superior Radioulnar
Joint are enclosed in a single Joint capsule.The capsule is
fairly loose .
 Anteriorly, it is attached above coronoid and radial fossa
 Posteriorly ,it is attached above Olecranon fossa.
LIGAMENTS
 MEDIAL COLLATERAL LIGAMENT
Extends from Medial epicondyle of Humerus to Coronoid and
Olecranon process of Ulna
 LATERAL COLATERAL LIGAMENT
Extends from Lateral Epicondyle of Humerus to Annular
Ligament and Olecranon process.
 ANNULAR LIGAMENT
It encircles the head of Radius
LIGAMENTS OF ELBOW
Movements of Elbow Joint
 FLEXION-EXTENSION ( 0-140 degree)
 AXIS-------Medio Lateral Axis (Passess through Trochlea)
 PLANE------Saggital plane
 MUSCLES:
 FLEXORS OF ELBOW
 Biceps Brachi---Powerful flexor when elbow is in 90 degree
Flexion.
 Brachialis----Flexor of elbow in all position
 Brachioradialis---Flexor of elbow in midprone position
BICEPS BRACHI
EXTENSORS OF ELBOW
 TRICEPS is the powerful extensor of the Shoulder
 Long head of Triceps depends on Shoulder Position
 Medial head of Triceps is active in unresisted Elbow
extension
 All three Heads of Triceps are active when heavy resistance is
given to Extension.
CARRYING ANGLE
 The angle formed between the axis of Humerus and the
Longitudinal axis of Forearm
 Normal angle:
In MEN=5 degree ,
In WOMEN=10 degree
 The angle is more in Women due to Wider Pelvis
 CUBITUS VALGUS: Increase in Carrying Angle
 CUBITUS VARUS: Decrease in Carrying Angle
CARRYING ANGLE
SUPERIOR RADIOULNAR JOINT
 ARTICULATION
 The Radial notch on Ulna articulate with Head of Radius
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along with Annular Ligament & Capitulum.
LIGAMENTS
Annular Ligament-----circle the head of Radius and keeps the
Ulna together.
Quadrate Ligament----extends from the Inferior edge of
radial notch to Neck of Radius
Oblique cord------attached to inferior part of Radial notch
on Ulna to just below Radial Tuberosity
INFERIOR RADIOULNAR JOINT
 ARTICULATION
 The Ulnar notch of Radius articulates with head of Ulna
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along with Articular Disc.
LIGAMENTS
Anterior Radio Ulnar Ligament----attached to anterior
aspect just above the Ulnar head to above Ulnar notch.
Posterior Radio Ulnar Ligament---attached to posterior part
of Ulnar head to above Ulnar notch.
Interosseous Membrane---binds the shaft of Radius and Ulna
together.
MUSCLES
 PRONATOR TERES----- helps in Pronation,it acts in all
position of Elbow, helps in Stabilization of Superio Radio
Ulnar Joint. Active during rapid and resisted Pronation.
 PRONATOR QUADRATUS---- helps in Pronation in all
position of Elbow
 SUPINATOR---------helps in Supination in all position of
Elbow
 BICEPS BRACHI-------- helps in Supination when Elbow is
flexed to 90 degree
MOVEMENTS
 Pronation & Supination
 Axis of movement extends from radial head to Ulnar head
 Pronation and Supination movement is good when Elbow is
Flexed to 90 degree
 In Elbow extended position Pronation is limited due to
passive tension in Biceps Brachi. Supination is limited due to
passive tension in Interosseous Membrane.
PROBLEMS OF ELBOW
 TENNIS ELBOW or LATERAL EPICONDYLITIS:
 Inflammation at origin of Extensors of Wrist at Lateral
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Epicondyle.
It is caused due to repeated forceful contraction of Wrist
Extensors.
Extensor carpi radialis brevis is affected
GOLFER’S ELBOW or MEDIAL EPICONDYLITIS:
Inflammation at origin of Flexors of Wrist at Medial
Epicondyle.
Repetitive contractions of Pronator Teres,Flexor Carpi
Ulnaris
PROBLEMS OF ELBOW
 NURSEMAID’S ELBOW or PULLED ELBOW
 In small children the radial head is not fully developed ,lifting
small child up in to by one hand may cause the RADIAL
HEAD to slip out of Annular Ligament.
 CUBITAL TUNNEL SYNDROME
 Repetitive forceful contractions of Flexor carpi Ulnaris may
compress Ulnar Nerve as it passess through the cubital tunnel
between Medial Epicondyle of Humerus and Olecranon
process of Ulna.