This document discusses the pain mechanisms involved in lateral epicondylalgia (LE), commonly known as tennis elbow. It outlines that LE pain occurs at the lateral epicondyle due to overuse and microtrauma of the wrist extensor tendons. The mechanisms of pain in LE are multifactorial, involving degeneration of the tendon collagen, changes in the pain system through peripheral and central sensitization, and motor impairments including reduced grip strength. Trigger points in the forearm muscles can also perpetuate LE pain through referred pain patterns and central sensitization processes. While the pain initially occurs at the lateral epicondyle, motor impairments and trigger points may help maintain the chronic pain state in LE.

1. WHAT DO WE KNOW ABOUT
THE PAIN MECHANISMS?
LATERAL EPICONDYLALGIA
Elena Ozaes Lara
e.ozaes@gmail.com
Centre de Fisioteràpia Punsola

2. Pain over the lateral epicondyle
Location: insertion of the extensor muscle mass of the
wrist and fingers
Pain can refer over the back forearm and the wrist
LATERAL EPICONDYLALGIA (LE):
CLINICAL SIGNS:
- Pain to direct palpaction over the lateral epicondyle
- Pain to resisted extension of the wrist and fingers
- Pain and weakness during grip strength testing

3. MECHANISMS OF PAIN
Multifactorial Character
Coombes B, Bisset L, Vicenzino B 2009
Pathophysiological
mechanisms of the
local tendon
Changes in
the pain
system
Impairment
in the
motor
system
LE

4. Repetitive microtraumas or direct trauma in the
proximal insertion of the extensors muscles of the
wrist and fingers
PATHOMECHANICS OF THE TENDON
Repetitive contractions of the muscle
- Degenerative process Tiny tears
- Anomalous vascular repair
- Angiofibroblastic tendinosis
Bales CP 2007, Kraushaar BS 1999, Fedorczyk JM 2006
MECHANISMS OF PAIN
Disorganized
collagen fibers

5. Muscles involved in the LE:
- ECRB (Extensor Carpi Radialis Brevis)
- ECRL (Extensor Carpi Radialis Longus)
- EDC (Extensor Digitorum Communis)
- Brachioradialis
The most frequent
MECHANISMS OF PAIN

6. - Overuse of the tendon
- Reparation of the tendon overwhelmed
- Non-inflammation process
absence of inflammatory cells
- Degenerative process
degenerative changes in the connective tissue
Actual studies…
Nirschl RP 2003, Vizencino B 2003
MECHANISMS OF PAIN

7. CHANGES IN THE PAIN SYSTEM
Mechanical stress
ECRB
stimulate
Peripheral liberation of neuropeptides:
• Substance P
• CGRP (Calcitonin Gene Related
Peptide)
Peripheral Sensitization
R. Torres 2005, Slater 2005, Coombes 2012
NEUROGENIC INFLAMMATIONStimulation of
more nociceptors
Mechanical
sensitization
Nociception
PRIMARY HYPERALGESIA
MECHANISMS OF PAIN

8. Central Sensitization
Changes primary
nociceptors
Neuronal excitability in
the spinal cord
CNS
stimulate
SECONDARY HYPERALGESIA - Pain outside injury area
- Acute pain to Chronic pain
Slater 2005, R. Torres 2005
MECHANISMS OF PAIN

9. MOTOR IMPAIRMENTS
- Reduction grip capacity Grip strength test
- Diminished muscle strength wrist and fingers extensors
- Morphological changes of the muscles moth eaten fibres,
fibre necrosis and signs of muscle fibre regeneration
- Altered motor control
TRIGGER POINTS AND MIOFASCIAL PAIN!!!
Coombes B, Bisset L, Vicenzino B 2009
MECHANISMS OF PAIN

10. TRIGGER POINTS (TP) AND MIOFASCIAL PAIN
Causes of formation Trigger Points:
- Trauma
- Forced posture
- Mechanical overcharge
- Psychological stress
Simons et al. 1999
Implication of the TP of the
forearm muscles in the
sensory and motor
impairments in LE patients
MECHANISMS OF PAIN

11. Referred pain in Trigger Points…
 Referred pain in active Trigger Points in the forearm
muscles (ECRB, ECRL, EDC, brachioradialis) have similar
patterns to the elbow and forearm pain in LE
O. Mayoral 2001, Ferández-Carnero 2007
MECHANISMS OF PAIN
CENTRAL PHENOMENA
liberation
Strain
Hypoxia
Distress
tissue
SENSITIZING
SUBSTANCES
Trigger
Point

12. Strain TP in the skeletal muscle (Central TP)
transmission
- Myotendinous insertion
- Tendon
- Bony insertion of the muscle
ENTHESOPATHY
TENDINOPATHY
(Insertional TP)
Central TP are perpetual factors of the LE?
First of all we have to treat the Central TP in LE?
MECHANISMS OF PAIN
Simons 2002, O. Mayoral 2001

13. Activation mechanisms of the Central TP:
 DIRECTS:
- Trauma
- Overstretched muscle
- Overstretched motor nerve
- Overcharge muscle
 UNDIRECTS:
- TP in muscles that refer pain to the afected muscle
- TP in antagonist muscles
- Nerve entrapment
MECHANISMS OF PAIN
O. Mayoral 2001

14. Muscles to know:
1. Inserted muscles in the lateral epicondyle:
ECRB, ECD, ECRL, brachioradialis, anconeus, supinator
2. TP that refer pain to the lateral epicondyle:
Supinator, brachioradialis, ECRL, tríceps, supraspinous, EDC,
anconeus
3. TP that active TP in muscles from section 1 and 2:
Scalene, Infraspinous, Supraspinous, Subclavious and Triceps
4. TP from agonist/antagonist muscles from section 1:
Biceps and Brachial / Wrist and fingers flexors
MECHANISMS OF PAIN
Continuous afferent
nociceptive inputs
from active TP
Pain Perception
Mechanical pain sensitivity
Pain intensity elbow and
forearm

15. QUESTION:
What come first…
…the pain over the lateral epicondyle?
OR
…motor impairment with the TP?
MECHANISMS OF PAIN

16. BIBLIOGRAFIA:
• Bales CP, Placzek JD, Malone KJ, Vaupel Z and Arnoczky SP. Microvascular supply of the
lateral epicondyle and common extensor origin. J Shoulder Elbow Surg. 2007 Jul-Aug;
16(4): 497-501
• Kraushaar BS, Nirschl RP. Tendinosis of the elbow (tennis elbow). Clinical features and
findings of histological, immunohistochemical, and electron microscopy studies. J Bone
Joint Surg Am. 1999 Feb; 81(2): 259-78
• Fedorczyk JM. Tennis elbow: blending basic science with clinical practice. J Hand Ther.
2006 Apr-Jun;19(2):146-53
• Nirschl RP, Ashman ES. Elbow tendinopathy: tennis elbow. Clin Sports Med. 2003
Oct;22(4):813-36
• Vicenzino B. Lateral epicondilalgia: a musculoskeletal physiotherapy perspective. Man
Ther. 2003 May;8(2):66-79
• Mayoral O, De Felipe JA, Fernández JM, Torres M. Study of attachment and taut band
tendemess of epicondyle muscles in epicondylitis. Journal of Musculoskeletal Pain
2001;9(Supl. 5):90
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Sports Med. 2009;43:252-258
• Torres R. Chronic myofascial pain: pathophysiology and therapeutic approach.
Fisioterapia. 2005 Mar;27(2)

17. •Slater H, Arendt-Nielsen L, Wright A, et al. Sensory and motor effects of experimental
muscle pain in patients with lateral epicondylalgia and controls with delayed onset muscle
soreness. Pain. 2005;114:118–130
• Coombes BK, Bisset L, Vicenzino B. Thermal hyperalgesia distinguishes those with severe
pain and disability in unilateral lateral epicondylalgia. Clin J Pain. 2012 Sept;28(7):595-601
• Fernandez-Carnero J, Fernandez-de-las-Penas C, Sterling M, et al. Exploration of the
extent of somato-sensory impairment in patients with unilateral lateral epicondylalgia. J
Pain. 2009;10:1179–1185
• Fernández-Carnero J, Fernández-de-las-Peñas C, de la Llave-Rincón AI, Ge HY, Arendt-
Nielsen L. Widespread pressure pain hyperalgesia as sign of central sensitization in
unilateral epicondylalgia: a blinded, controlled study. Clin J pain 2009. Sep;25(7):555-61
• Fernández-Carnero J, Fernández-de-Las-Peñas C, de la Llave-Rincón AI, Ge HY, Arendt-
Nielsen L. Prevalence of and referred pain from myofascial trigger points in the forearm
muscles in patients with lateral epicondylalgia. Clin J Pain. 2007 May;23(4):353-60
• Simons D, Travell J, Simons L. Dolor y disfunción miofascial. El manual de los puntos
gatillo. 2.ª ed. Madrid: Editorial Médica Panamericana; 2002.
BIBLIOGRAFIA:

18. Thank You!!!