I was lucky enough to be taught Pain Physiology and Mechanisms by Max Zusman in the second year of my undergraduate physiotherapy degree. Max had an aura; being in his presence you felt completely inferior yet utterly motivated and enlightened at the same time. There are a rare few who have changed the direction and reputation of physiotherapy to such an extent, but Max Zusman is unquestionably one of them. It was an honour to be taught by such an advanced mind, with his lessons on peripheral sensitisation, noxious stimuli and hyperalgesia sure to stay with me for life.
The news of Max's passing led to me re-reading his most recent articles. Zusman (2012) focuses on the necessity for physiotherapists to correctly use pain terminology. Those who attended the Victorian APA breakfast and listened to David Butler will understand the importance of correctly employing this jargon.
A statement which underpins physiotherapy is "(physiotherapy) delivery entails subjecting patients to graduated exposure to mechanical stimuli" through employing a "means of mechanical stimulus-induced pain inhibition" (Zusman, 2012). Although many techniques are utilised, most, if not all, are simply the 'graduated exposure' to a nociceptive stimulus.
The article highlights the difference between various types of pain, which will be elaborated further.
Nociceptive Pain - pain designed as a warning signal, regular mechanical or thermal stimuli which doesn't evoke tissue damage, is localised, intermittent pain which does not sensitise the area, it is not a pathology, just a normal pain mechanism
Inflammatory Pain - consists of peripheral sensitisation (chemical excitation of peripheral nociceptors due to lowering of pain thresholds to mechanical or thermal stimuli) and chemical sensitisation, both result in a non-noxious stimuli now causing pain. Pain may occur spontaneously and continues although the stimulus is no longer present, with pain often exceeding beyond the localised area of tissue injury. Central sensitisation heightens, spreads and perpetuates peripheral pain which can become widespread causing "functional pain" (often associated with psychosocial issues).
Neuropathic Pain - “pain arising as a direct consequence of a lesion or disease affecting the somatosensory system” (Zusman, 2012), a diagnosis of neuropathic pain requires axonal or fascicular damage resulting in the development of specific sites of "nerve impulse generation" which spontaneously emit neural impulses in addition to reacting to normal "mechanical, thermal and chemical stimuli". These impulses instigate central sensitisation in the central nervous system using the same mechanisms as inflammatory pain, with 'functional pain' being the enduring disability of these inhibitory pain systems.
"Physiological and anatomical changes affecting mechanisms of endogenous pain inhibition following peripheral nerve damage render many common methods for the induction of pain relief only partially effective/ineffective." (Zusman, 2012)
Functional Pain - collection of widespread, chronic pain disorders with no peripheral pathology discovered, including fibromyalgia, tension-type headaches, chronic fatigue, irritable bowel syndrome, temperomandibular joint disorders, individuals display increased sensitivity to mechanical/thermal stimuli, evident of central sensitisation.
In conclusion, Max provided a succinct article to "inform (musculoskeletal physiotherapists') clinical reasoning and decision-making process and smooth the way for mutual understanding with fellow orthodox health care professionals".
Vale Max Zusman
Zusman, M. (2012). A note to the musculoskeletal physiotherapist. Journal of back and musculoskeletal rehabilitation, 25(2), 103-107.