IPHREHAB : PAIN cause and why?

IPHREHAB
PAIN

• Unpleasant sensation.
• Localised or not localised.
• Described differently.
• Associated anxiety and urge to escape or terminate the feeling.
• Dualality.

• Acute pain associated with behavioural arousal and stress response
• Increased BP, pupil size, plasma cotisol
• Local muscle contraction (limb flexion, abdominal wall rigidity)

PERIPHERAL MECHANISMS

1. Primary Afferent Nociceptors
2. Peripheral nerve containing three different types of axons-motor, sensory, sympathetic post ganglionic.
3. Cell bodies in dorsal root ganglion.
4. Two processes, peripheral and central.
5. Primary afferent are Aδ & C (unmelinated) axons.
6. Fibers present in skin and deep somatic and visceral structures.
7. Most of these fibers respond maximally only to intense painful stimulus and produce subjective experience of pain when electrically stimulated
8. This defines them as primary afferent nociceptors.
9. Nociceptors respond to many different stimuli- heating, intense mechanical stimuli (pinch), irritating chemicals.

Sensitisation

• Intense, repeated and prolonged stimuli to an inflamed tissue lowers the threshold for activating primary afferent nociceptors.
• Frequency of firing is higher.
• Mediators like bradykinin, PG’s, LT contribute. 
• Even innocuous stimulus can produce pain

• Clinically important as it contributes to tenderness, soreness, and hyperalgesia.
• Sensitisation has importance in visceral tissue.
• Normally viscera is insensitive but in presence of inflammatory mediators, the sensitivity increases especially to mechanical stimulus.
• Such afferents are termed as silent nociceptors

Nociceptor induced inflammation

• Neuroeffector function
• Contan polypeptides in peripheral terminals - substance P.
• Released from primary afferent nociceptors causing v/d, degranulation of mast cells, chemoattractant and increases production and release of inflammatory mediators.
• Tissue protectors due to these mechanisms.

CENTRAL MECHANISMS

• Spinal Cord and Referred Pain
• Afferent Axons enter dorsal root→ dorsal horn → spinal neurons.
• Each afferent neuron contacts many spinal neurons and each spinal neuron receives convergent input from many primary afferents.
• Convergence takes place and this underlies the phenomenon of referred pain.

Ascending Pathways

Afferent neuron → Spinal neurons → contra lateral side → spinothalamic tract → thalamus (several regions) → cerebral cortex (several regions).

Spinothalamic tract is crucial as damage causes impairment in transmission of these sensations.

IPHREHAB: UPPER LIMB ORTHOTICS AND NERVE INJURY

IPHREHAB


UPPER LIMB ORTHOTICS and NERVE INJURIES


PERIPHERAL NERVE INJURIES


AIM OF ORTHOTICS
—  To keep denervated muscle from remaining in an overstretched position
—  To prevent joint contracture
—  To improve functional use of the hand
—  Imp. issue to consider before prescribing an orthoses- etiology & prognosis for neuropathy
—  If injury- Neuropraxic - prefabricated orthotics & cheap


RADIAL NERVE INJURY: 


Ideal splints allows
—  Tenodesis action
—  Finger extension with wrist flexion
—  Wrist extension with finger flexion
—  Protects against over-lengthening of paralyzed wrist extensors & shortening of flexors.


PROXIMAL RADIAL NERVE INJURY


DEFORMITIES                                                        ORTHOTIC OBJECTIVES


1. WRIST DROP                                                         PREVENT WRIST DROP
                                                                                  ASSIST WRIST EXTENSION


2. MCP AND IP CONTRACTURE                             PREVENT DERFORMITY  


3. THUMB WEB SPACE CONTRACTURE                ASSIST THUMB 
                                                                                      EXTENTION/ABDUCTION
                                                                                 MAINTAIN THUMB WEB SPACE


4. FLATENING OF PALMER ARCH                    MAINTAIN TRANSVERSE ARCH


   —  Forearm-based dorsal or volar static wrist extension splint with dynamic out triggering for the fingers (Directly over the proximal   phalanges)


PROXIMAL MEDIAN NERVE INJURY
—  As the recovery is poor, splinting of this level of deformity to maintain passive ROM is appropriate for tendon transfers


SPLINTS:
—   Thumb spica splint
            Resting hand splint
           Tendon transfers


DEFORMITY                                                ORTHOTIC OBJECTIVES


1.Forarm and Thenar Atrophy                       Prevention   


2. Thumb on Finger plane                               Maintain Thumb in Adduction/Abduction


3.Thumb web space contracture                    Maintain Thumb Web Space


4.Flattening of transverse palmer arch          Maintain transverse Palmer arch


5.Others                                                            Assist MIP / IP  Flexion
                                                                           Reduce pain by limited wrist thumb


 As the recovery is poor, splinting of this level of deformity to maintain passive ROM is appropriate for tendon transfers.


DISTAL MEDIAN NERVE INJURY


DEFORMITY                                          ORTHOTIC OBJECTIVES


1.Thenar Atrophy                                     Prevention   


2. Thumb on Finger plane                       Maintain Thumb in Adduction/Abduction


3.Thumb web space contracture             Maintain Thumb Web Space


4.Others                                                    Assist MIP / IP  Flexion
                                                                   Reduce pain by limiting wrist and thumb.


—  SOFT DYNAMIC THUMB ABDUCTION SPLINT
—  THUMB SPICA SPLINT
—  C-BAR/OPPONENS BAR TO STABILIZE THE THUMB IN OPPOSITION


CARPAL TUNNEL SYNDROME :


—  VOLAR WRIST ORTHOSIS
—  Wrist-between 10º of extension & neutral position


PROXIMAL & DISTAL ULNAR NERVE INJURY


DEFORMITY                                                            ORTHOTIC OBJECTIVES


1.Flattening of Transverse Palmer Arch            Maintain Transverse Palmer arch.


2.During Pinch, 1st IP hyperflex &/ 1st              Stabilize 1st MCP
   MCP hyperextends.


3. Partial Claw hand                                              Improve Grasp
                                                                               Limits 4th and  5th MCP extention
4.Interosseous atrophy
   Hypothenar atrophy
   5th MCP jt. contracture


ULNAR NERVE INJURY


—  LMB Ulnar Nerve Splint. For ulnar nerve injury and boxer’s fracture of 4th and 5th metacarpal.
—  Used to prevent shoulder subluxation in patient with
—  Brachial plexus injury
—  Hemiplegia
—  Central cord syndrome


SHOULDER SLINGS
 This restrict movement of the shoulder by keeping the shoulder by keeping the humerus in abduction & internal rotation & placing the elbow in flexion.


SPASTICITY
PRINCIPLES
—  Prolonged muscle stretch to reduce spasticity
—  Positioning opposite to patterns of spasticity to inhibit or prevent development of increased tone
—  Tactile stimulation to facilitate hypotonic muscles
—  Splint must incorporate both the wrist & fingers in order to stretch the long finger flexor muscles
—  Splints are moulded to provide 30º of wrist extension , 45º of MCP flexion & full IP extension, finger abduction & thumb extension & abduction