1. Pathomechanics of elbow)
Dr .Manal Radwan Salim
Lecturer of Physical Therapy
BiomeII
Fall
Tuesday

2. Elbow/ Forearm Anatomy
Arthrology and Movements
Humeroulnar Humeroradial
Proximal & Distal Radioulnar
Ligaments and Capsule:
Joint Capsule
Ulnar Collateral (UCL)
3 bundles
Lateral Ulnar Collateral (LUCL)
Radial Collateral (RCL)
Annular Interosseus Membrane

3. Common elbow abnormalities
1- Changes in Carrying Angle
the normal value of carrying angle is
10-5 degrees valgum
a) Cubitum Varum: abnormal decrease in carrying angle.
b) Cubitum Valgum: abnormal
increase in the angle.

4. 2- Changes in bony alignment following fractures:
Fracture of distal humerus or proximal ulna can alter the normal orientation of the articular surfaces of humeroulnar articulation.

5. a)From frontal view:
Any change in the relative alignment olecranon between the two humeral epicondyles affects both flexion and extension ranges

6. ii. a hypothetical increase in the superior orientation of the trochlear notch increases extension ROM and decreases flexion ROM.
2- Cubitum Recurvatum:
hyperextension of elbow joint.

7. 3-Humeroulnar Disolcation
Posterior dislocation:
As there is little bony limitation to the trochlear notch being pushed off trochlea.
b) Posterolateral dislocation:
More frequent, occur in a combination of lateral and posterior movement of the forearm resulting from a force directed laterally on the distal forearm.

8. 4- Superior radioulnar dislocation “pulled elbow injuries”
Occur at preschool children due to weakness of the annular ligament that allow the radial head to slip away from its ring by the tensile force applied to fore arm

9. 5-Joint swelling and elbow flexion
Position of comfort in case of swelling is significant elbow flexi which is due to minimized tension on joint capsule at 80 degree flexion thus reducing stress on ligaments and minimize pain. But if condition persists this leads to flexion contractures.

10. 6-Bursitis
Superficial location makes it extremely susceptible to injury (acute or chronic) --direct blow

11. 7-Musculature/Tendinitis
a) Medial Epicondylitis – chronic “Pitcher’s, Golfer Elbow” :
Caused by repeated flexion (common flexor tendon), valgus stresses, faulty biomechanics
b) Lateral Epicondylitis – chronic “Tennis Elbow”
Caused by -overuse of extensor /supinator muscles, faulty biomechanics (common extensor tendon).
-faulty backhand, too much topspin, too small or large grip.

12. 9- pathomechanics of Muscles around elbow
Biceps Brachii
Brachioradialis
Pronator Teres
Brachialis
a) Flexor groups:

13. i. Biceps brachii Effect of weakness:
Loss of flexion and radioulnar supination strength that is compensated by other muscles.
Also may cause slight weakness in shoulder flexion
Supinated pronated

14. Effect of tightness:
Limited extension range in elbow and shoulder with tightness degree changes by alteration in other joint positions
if Shoulder in extension position lead to limit extension range at elbow and vice versa
Forearm pronation lead to limit extension range at elbow and vice vera

15. ii. Brachiallis
Brachialis
Effect of weakness: Decreased elbow flexion in all forearm ranges.
Effect of tightness: Limited extension range regardless of shoulder and forearm position.
n.b. differentiate between brachialis tightness and anterior capsular tightness
Tight muscular tissue feel rubbery or springy at end range. Capsular tightness end feel is harder and less spring

16. iii. brachioradialis Effect of weakness: Effect of tightness:
Decreased elbow flexion strength in addition to decreased resisted pronation and supination as forearm moves toward neutral position
Effect of tightness:
Limited extension range in elbow and supination and pronation range
During rapid elbow flexion it acts as stabilizing to elbow joint against radial aaceleration

17. iv. Supinator Effect of weakness:
Decreased forearm forceful supination strength in case of intact biceps.
No supination with elbow extended.
Effect of tightness:
A two joint muscle thus max tightness appear when performing elbow extension and pronation

19. i. Pronator teris Effect of weakness: Effect of tightness:
Pronator Teres
Effect of weakness:
Decreased elbow flexion and
forearm pronation strength
In loading situations as
loosening a screw
Effect of tightness:
Limited extension range in elbow and supination. A two joint muscle thus max tightness appear when performing elbow extension and supination

20. ii.Triceps brachii Effect of weakness: Effect of tightness:
A profound decrease in elbow extension.
In tetraplegia with zero triceps push up could be done with elbow mechanically locked in hyperextension.
Effect of tightness:
Limited flexion range in elbow and may contribute to diminished shoulder elevation ROM that could interferes with functional daily activities as most daily activities can be performed with a total elbow flexion excursion of about 100°. Ex personal care activities as feeding and hygeine.

21. Other j positions
Effect of tightness (range)
Effect of weakness (strength)
Muscle
-Shoulder radioulnar
Elbow ext. range
pron. Range
Elbow flex. strength
flex. strength at shoulder
Sup. strength
Biceps brachii
Non
elbow ext
elbow flex. strength in all forearm positions
brachialis
elbow flex strength
resisted pron. and sup. force output as forearm moves toward neutral position
brachioradialis
pron
forceful sup and pron with extended elbow
supinator
Radioulnar
sup
resisted elbow flex
resisted in pron
Pronator teres
elbow flex
elbow flexion strngth
Triceps brachii