1. (Transcutaneous Electrical Nerve Stim) TENS for Pain Control

2. Bodychart Pain Drawing

3. VAS

4. Spadoni G et al. The Evaluation of Change in Pain Intensity: A Comparison of the P4 and Single-Item Numeric Pain Rating Scales. J Orthop Sports Phys Ther 2004;34:

6. Chung Faces Pain Rating Scale

7. THEORIES & MODELS OF PAIN CONTROL MECHANISMS

8. ASSUMPTIONS
These concepts involve OVERLAPPING PROCESSES that occur normally
Use these to better understand pain perception and as a rationale for your direct interventions for pain control

9. STIMULATION OF MECHANORECEPTORS
Accomplished everyday by:
Rubbing a painful area
“Walking off” the pain
Stimulation of mechanoreceptors should be at the same neurological level as the pain.
Stimulation of A-beta fibers does control the pain to some degree, BUT HOW ????????

10. Endogenous Opiates Theories
Key neurotransmitters are
Enkephalin
Endorphin
Serotonin
Substance P
Binding of endogenous opiates to receptor sites inhibits transmission of “pain signals” to the brain.

11. Presynaptic Inhibition @ the Dorsal Horn (Gate Control)

12. Gate Control / Presynaptic Inhibition: Clinical Application
Massage, heat, ice, pressure, exercise, stretching, manual therapy
TENS : rapid stimulation of large afferents by using
- High Frequency
- Short Pulse Duration (width)
- Sensory amplitude
Called Conventional / High Freq TENS
Ideal for acute pain

13. Descending Inhibition of pain via PAG & RN

14. Inhibition of pain by Endorphin (also decending)

15. Descending Inhibition & Endorphin: Clinical Application
massage, ice, pressure (massage), exercise, manual therapy
TENS - activate small afferents; A delta & C fibers
- Low Frequency
- Long (high) pulse duration
- High Amplitude; uncomfortable
Called Low Freq / Acupuncture-likeTENS
Targets chronic pain

16. A word about COUNTER-IRRITANT CREAMS
Old concept - “brain gives preference to most prominent sensations”
Many creams & rubs such as Ben-Gay, Icy-Hot, Mineral Ice, Atomic Balm, Cramergesic, and many “liniments” are classified as “counterirritant creams”; but think about how the application and the active ingredients CAN TRIGGER pain control mechanisms.
Word of caution

17. TENS Devices: Parameters you must master for HF & LF TENS
Amplitude
Frequency
Duration / Width
Modulations - to delay the onset of accommodation
Electrode Placement
Patient Instruction in home use

18. Examples of Current Modulations used by TENS units to delay accommodation
Name them

19. Electrode Placement Rationales
On & over the area of pain
Surround the area of pain (pass e-stim thru the area of pain)
Away from the site of pain but still depolarize the nerve(s) that supply the area of pain:
Stim the peripheral nerve carrying the pain (IF the nerve is superficial & proximal to the pain)
Stim within the same dermatome or myotome as the area of pain.
Stim the nerve plexus carrying pain stimulus (rare & only possible at brachial plexus)
Acupuncture Points   

20. TENS for Pain: Knowledge you must convey
Sensory fibers activated
Pain control theories utilized
Timeframe for pain control
Treatment time
Applicable to what type of pain?

21. Sampling of Evidence on TENS

22. Variation and Inconclusiveness
Efficacy: Mixed results in research have occurred due to several factors, such as waveform type, frequency, pulse rate, intensity, electrode placement, treatment time, outcome measures (pain), systematic vs individualized Rx.