Shoulder pain affects up to a quarter of the general population and is often slow to resolve, with about half reporting complete resolution of pain after 18 months. 

Half of those who report ongoing pain also report chronic disability, limiting their daily activities. 

Dr Leanda McKenna APAM, a researcher and lecturer at Curtin University and a clinical physiotherapist at Fiona Stanley Hospital, has been involved in shoulder pain research for almost 20 years. 

Her most recent research paper, published in Musculoskeletal Science and Practice, explores the role of central sensitivity in shoulder pain and associated disability. 

Central sensitivity occurs when a person’s central nervous system’s nociceptive neurons’ response is increased to stimuli, even those that would not normally cause pain. 

This may result in persistent pain and is potentially linked to slower recovery times and a poorer prognosis. 

‘It’s really important for physios to approach exercise prescription carefully when central sensitivity could be at play. 

'These patients are less likely to resolve their pain or to respond well to exercise—a mainstay of physiotherapy treatment. 

'Critically, they are less likely to get the hypoalgesic effects from exercise that people without central sensitivity receive,’ Leanda says. 

‘We need to be more careful about saying to people with central sensitivity that “it’s okay to push through pain” as this may worsen the pain sensitivity. 

'Consequently, their progress will be slower than others.’ 

Leanda’s interest in the relationship between shoulder pain, central sensitivity and disability was piqued when she started looking at the research regarding the prevalence of central sensitivity in patients with shoulder pain, which showed a prevalence rate of eight to 63 per cent depending on the study—a huge range. 

The methods used for testing central sensitivity also varied quite significantly between studies that used patient-reported outcome measures and those using quantitative sensory testing approaches. 

‘I wanted to know how many people who walk into my clinic with shoulder pain had central sensitivity and to use a simple patient-reported outcome measure to screen for this. 

'I needed the sample to be Australian and reasonably sized—that was one reason for doing the study,’ Leanda says. 

‘I also wanted to explore the relationship between disability and central sensitivity in people with shoulder pain. 

'Are they directly related or are they a function of confounding factors such as obesity or smoking? 

'I wanted to understand that relationship better so that I could help my patients.’ 

The resulting study used a cross-sectional design to collect data via online surveys, using the Central Sensitisation Inventory (here) and the Shoulder Pain and Disability Index (pdf). 

Additional confounding factors and variables were collected, including the existing clinical diagnosis and symptoms, gender, age, socio-economic status, obesity, psychological distress, sleep quality, physical activity, smoking status, ethnicity and neuropathic pain. 

A total of 249 people were surveyed, a cohort determined to be large enough to show any relationships if they were present. 

The population was 80 per cent female, with ages ranging from 19 to 82 years old. 

About 44 per cent had been diagnosed with rotator cuff-related shoulder pain and a further 5.6 per cent with frozen shoulder. 

A small percentage had arthritis and other conditions and 35 per cent reported no clinical diagnosis. 

The results surprised the researchers, says Leanda. 

‘About 48 per cent of Australians who experience shoulder pain have central sensitivity—that was a lot more than I expected. 

'Therefore, nearly 50 per cent of people coming into the clinic with shoulder pain also experience central sensitivity. 

'In fact, quantitative sensory testing usually identifies central sensitivity more often than patient-reported outcomes, meaning 50 per cent is likely an underestimate,’ she explains. 

‘It also means that I should be using the patient-reported outcome measure for every patient who comes in with shoulder pain because 50 per cent is quite high.’ 

The study highlighted the relationship between shoulder disability and central sensitivity, showing that the two are related regardless of confounding factors. 

‘Irrespective of whether the confounding factors were in the model or not, disability and central sensitisation are related. 

'The variance in central sensitivity accounts for a significant proportion of the variance in disability. 

'If we want to address a person’s disability, we need to concentrate on central sensitivity—that is the take-home message of the study,’ Leanda says. 

‘It was really interesting to compare the models with and without the confounding factors. 

'Both versions show that central sensitivity and disability are related but although smoking and obesity are still important for us to tackle, they don’t fully explain this relationship.’ 

About 20 per cent of the people with musculoskeletal shoulder symptoms also had symptoms of neuropathic pain, suggesting that clinicians should consider and screen for neuropathic pain in addition to central sensitisation so that the appropriate treatments and interventions can be incorporated into management and care. 

The study did have some limitations, including a gender disparity—the survey cohort was 80 per cent female—and it did not take into account additional comorbidities and pain in other body regions, which could also affect central sensitivity. 

While patient-reported data on the clinical diagnosis was captured, a link between the diagnosis and central sensitivity was not examined, due to both the size of the study and its nature. 

Leanda says that future studies should address some of these gaps. 

‘The clinical diagnosis is needed to see if we can tease out people with a certain type of diagnosis who might be more likely to have central sensitisation. 

'For example, I suspect that people with adhesive capsulitis are more likely to have central sensitisation compared to other types of diagnoses. 

'But that would involve a diagnostic bank of testing,’ she says. 

For now, Leanda is interested in looking at central sensitivity in a different population. 

‘I’d like to better my understanding of central sensitivity within the population I see in the neurosurgical spinal assessment clinic where I work. 

'Exploring related factors within that sample would be helpful as well.’ 

Reference: McKenna et al. Increased central sensitivity is associated with greater shoulder disability in people with musculoskeletal shoulder symptoms: a cross-sectional study. Musculoskeletal Science and Practice. 2025 (78) (read here)

Infographic: coming soon