The document summarizes the biomechanics of the elbow complex. It describes the main joints and muscles that make up the elbow, including the elbow joint itself, the proximal and distal radioulnar joints. It discusses the range of motion, ligaments, common injuries like tennis elbow, and factors that can affect elbow muscle activity. Treatment options for some injuries are also mentioned.
2. 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 OF UPPER EXTREMITY.
3. ELBOW JOINT
• IT IS A COMPOUND JOINT THAT
FUNCTIONS AS A MODIFIED OR
LOOSE HINGE JOINT.
• ONE DEGREE OF FREEDOM IS
POSSIBLE i.e FLX. AND EXT. IN
SAGITTAL PLANE AND CORONAL AXIS.
4. COMPOSITION OF
ELBOW COMPLEX
1. IT INCLUDES
• ELBOW JOINT
(HUMEROULNAR
(H.U)AND
HUMERORADIAL (H.R)
JOINTS)
• PROXIMAL
RADIOULNAR JOINT
• DISTAL RADIOULNAR
JOINT.
5. STRUCTURE:ELBOW JT.
HUMEROULNAR & RADIOULNAR
ART
1. ARTICULATING SURFACES ON
HUMERUS
– ANTERIORLY,TROCHLEA AND CAPITULUM.
– POSTERIORLY,DISTAL HUMERUS
INDENTED BY A DEEP FOSSSA CALLED
OLECRANON FOSSA.
6. 2 ARTICULATING SURFACES ON
RADIUS & ULNA
– ULNAR ARTICULATING SURFACE
ON H.U JT. IS TROCHLEAR NOTCH.
– DISTAL END BY ULNAR CORONOID
PROCESS.
– THE RADIAL ARTICULATING
SURFACE IS HEAD OF RADIUS.
– RADIAL HEAD’S CONVEX RIM FITS
INTO CAPITULOTRCHLEAR NOTCH
13. Factors affecting elbow
mscl activity
• NO. OF JOINTS CROSSED BY MSCLES
• PHYSIOLOGIC CROSS-SECTIONAL
AREA(PCSA)
• LOCATION IN RELATION TO JT.
• POSITION OF FOREARM
• MAGNITUDE OF APPLIED LOAD
• TYPE OF MSCLE ACTION
• SPEED OF MOTION(SLOW OR FAST)
• MOMENT ARM AT DIFF. JT POSITION
• FIBER TYPE
18. CARRYING ANGLE
• THE FOREARM LIES SLIGHTLY LATERAL TO
THE HUMERUS WHEN THE ELBOW IS FULLY
EXTENDED IN ANATOMIC POSITION.
• THE LONG AXIS OF HUMERUS AND LONG
AXIS OF FOREARM FORM THE CARRING
ANGLE
• NORMAL IN MEN = 5’ , WOMEN = 10’ TO 15’
19. • INCREASE IN CARRYING ANGLE IS
CONSIDERED TO BE ABNORMAL ,ESPECIALLY
IF IT OCCURS UNILATERALLY.
• WHEN THE ANGLE INCREASED BEYOND THE
AVERAGE , IT IS CALLED CUBITUS VALGUS
• THE CONFIGURATION OF THE TROCHLEAR
GROOVE DETERMINES THE PATHWAY DURING
FLEXION AND EXTENSION.
20. Effects of age& injury
• AGE- DUE TO ADVANCING AGE,THE
DEC. IN MSCLE STRENGTH AND LESS
PHYSICAL ACTIVITY TENDS TO DEC IN
ROM
• INJURY-IJURIES ARE FREQUENT. IT
IS ONE OF THE MOST COMMON SITES
FOR APOPHYSITIS (STRAIN AT
APOPHYSIS)
21. Compression injuries
• EXCESSIVE COMPRESSION OFTEN RESULT
IN BONY FAILURE.
• FALLING ON HANDS WHEN ELBOW IS IN A
CLOSE –PACKED POSITION RESULT IN
TRANSMISSION OF FORCES
IF FORCES R TRANSMITTED TROUGH
RADIUS,DUE TO CONCOMITANT VALGUS
STRESS,A FRACTURE OF RADIAL HEAD ON
CAPITULUM
22.
23. Compression injuries
IF FORCE IS TRANSMITTED TO
ULNA,FRACTURE OF CORONOID OR
OLECRANON PROCESSES MAY OCCUR FROM
IMPACT OF ULNA ON HUMERUS
IF NEITHER RADIUS NOR ULNA ,THE
FORCE MAY B TRANSMITTED TO HUMERUS&
RESULTS IN SUPRACONDYLAR FRACTURE.
24. Distraction injuries
• A TENSILE FORCE OF SUFFICIENT
MAGNITUDE EXERTED ON A PRONATED OR
EXTENTED FOREARM MAY CAUSE RADIUS TO
BE PULLED INFERIORLY OUT OF THE
ANNULAR LIGAMENT
• COMMON IN YOUNG CHILDREN & RARE IN
ADULTS.
• LIFTING A SMALL CHILD UP IN AIR OR
YANKING A CHILD BY ONE HAND IS THE
USUAL CAUSATIVE MECHANISMAND
THEREFORE THE INJURYIS REFFERED TO AS
EITHER NURSEMAID’S ELBOW OR ’’PULLED
ELBOW’
25. Varus or Valgus Injuries
• DISTRACTION & COMPRESSION FORCES R
CREATED IF EITHER ONE OF COLLATERAL
LIG. IS OVERSTRETCHED OR TORN.
• OTHER CONDITIONS THAT MAY OCCUR IN
THROWING ELBOW INCLUDE ULNAR
NEUTRITIS, FLEXOR PRONATOR MSCL
STRAINS& MED. EPICONDYLITIS, LAT.
EPICONDYLITIS(TENNIS ELBOW)
26. TENNIS ELBOW
• THE CLASSIC TENNIS
ELBOW (EPICONDYLITIS
OF LAT.
EPICONDYLE)APPEARS TO B
CAUSED BY REPEATED
FORCEFUL CONTRACTION
OF WRIST EXTENSORS.
• SOME TREATMENT
INCLUDE
SPLINTING,FOREARM
SUPPORT BANDS &
TAPING,ULTRASOUND,
MANIPULATION,EXERCISE,
MOBILIZATION TECH.s
• STEROID INJECTIONS R
EFFECTIVE IN RELIEVING
PAIN.
