WHAT DO WE KNOW ABOUT

THE PAIN MECHANISMS?

LATERAL EPICONDYLALGIA

Elena Ozaes Lara e.ozaes@gmail.com Centre de Fisioteràpia Punsola

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

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

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

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

- 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

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 INFLAMMATION Stimulation of more nociceptors

Mechanical sensitization

Nociception

PRIMARY HYPERALGESIA

MECHANISMS OF PAIN

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

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

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

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

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

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

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

QUESTION:

What come first…

…the pain over the lateral epicondyle?

OR

…motor impairment with the TP?

MECHANISMS OF PAIN

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 • Coombes BK, Bisset L, Vicenzino B. A new integrative model of lateral epicondylalgia. Br J Sports Med. 2009;43:252-258 • Torres R. Chronic myofascial pain: pathophysiology and therapeutic approach. Fisioterapia. 2005 Mar;27(2)

•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:

Thank You!!!