The elbow complex provides mobility and stability to the hand. It is made up of three joints: the humeroulnar joint between the humerus and ulna, the humeroradial joint between the humerus and radius, and the superior radioulnar joint between the radius and ulna. These joints allow for flexion-extension and pronation-supination movements. The elbow is stabilized by ligaments connecting the humerus, ulna, and radius. Common problems affecting the elbow include lateral epicondylitis, medial epicondylitis, nursemaid's elbow, and cubital tunnel syndrome.

1. U.RADHAKRISHNAN.M.P.T
BIOMECHANICS OF ELBOW
COMPLEX

2. 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

3. ELBOW JOINT

4. 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

5. 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

6. 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.

7. 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.

8. 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.

9. 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

10. LIGAMENTS OF ELBOW

11. 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

12. BICEPS BRACHI

13. 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.

15. 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

16. CARRYING ANGLE

17. SUPERIOR RADIOULNAR
JOINT
 ARTICULATION
 The Radial notch on Ulna articulate with Head of
Radius 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

18. INFERIOR RADIOULNAR
JOINT
 ARTICULATION
 The Ulnar notch of Radius articulates with head
of Ulna 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.

19. 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

20. 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.

21. PROBLEMS OF ELBOW
 TENNIS ELBOW or LATERAL EPICONDYLITIS:
 Inflammation at origin of Extensors of Wrist at
Lateral 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

22. 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.