How to access this video
You can purchase a video subscription to access all Physiotherapy UK videos.
Already subscribed? Continue to The specifics of non-specific arm pain .
Dr Jane Greening, Hon. Senior Research Fellow, Division of Clinical Laboratory Investigation Brighton and Sussex University Medical School
Non-specific arm pain (NSAP) is a common chronic upper limb pain disorder that has previously been referred to as repetitive strain injury. NSAP is frequently associated with tasks that involve repetitive upper limb activities What differentiates NSAP from other specific work-related upper limb conditions is the lack of obvious tissue injury on clinical testing. This presentation will focus on the evidence that inflammatory nerve injury contributes to symptoms and will discuss how NSAP may fit into a broader spectrum of neuropathic pain conditions.
Non-specific arm pain (NSAP) is a common chronic upper limb pain disorder previously referred to as repetitive strain injury (RSI). NSAP is frequently associated with tasks that involve repetitive upper limb activities, such as intense computer use and light production work. What differentiates NSAP from other specific work-related upper limb conditions is the lack of tissue injury on standard clinical examination. Because of the apparent lack of physical signs, research into NSAP has mainly focussed on psychosocial, personal and physical risk factors for the condition. However, successful treatment of this complex condition is dependent on a better understanding of all underlying mechanisms. It is only recently that the complex mechanisms underlying NSAP are being revealed. Although psychosocial stressors contribute to symptoms, the underlying pathophysiology appears to be one of subtle neuro-musculoskeletal injury that involves inflammation and tissue ischemia. Such features are likely to be a consequence of frequent low force, highly repetitive muscle activity that is carried out in constrained and sustained working postures. Patients consistently show features of a minor neuropathy, with clear signs of nerve trunk mechanical sensitivity and changes in peripheral nerve function. The consequences of such a minor nerve injury have been underestimated. It is now apparent that peripheral nerve inflammation in the absence of axonal degeneration is sufficient to drive abnormal nociceptive activity (e.g. axonal mechanical sensitivity). These changes would contribute to painful symptoms and to nerve trunk mechanical sensitivity with nerve movement tests. Such changes in nociceptive firing also lead to chronicity. Simple analgesics and non-steroidal anti-inflammatory medication are usually ineffective in treating NSAP. However, where there are signs of peripheral nerve involvement, neuropathic pain medications should be considered. Recent studies are beginning to reveal a close relationship between NSAP and other chronic pain syndromes that present without obvious clinical sign of tissue injury, e.g. fibromyalgia.