SHOULDER PAIN AND SUBACROMIAL SPACE

Is there a relationship between reduced subacromial space and shoulder pain?

Shoulder pain, particularly subacromial pain (Subacromial Pain Syndrome - SAPS), is one of the most common musculoskeletal conditions. Reduced subacromial space, also known as the acromiohumeral distance (AHD), has often been associated with this condition. However, scientific literature has raised doubts about the validity of this correlation. A 2020 study published in *Nature*, conducted by Park et al., addressed this question through a systematic review and meta-analysis, with the aim of clarifying whether a relationship exists between AHD and shoulder pain.

The analysis focused on three key questions:

1) Is there a difference in subacromial space (AHD) between people with and without shoulder pain?

The authors’ first objective was to determine whether there was a significant difference in subacromial space between people with shoulder pain and those without symptoms. The result? No statistically significant differences emerged between the two groups. This suggests that reduced subacromial space alone may not be a determining factor in pain. This finding challenges the traditional idea that a reduced AHD is directly linked to shoulder pain symptoms.

2) Is there a linear correlation between subacromial space, pain, and function?

The second question sought to determine whether there was a linear relationship between AHD and pain or functional disability. However, the results were inconclusive. Although some studies reported a weak correlation, most of the literature has failed to demonstrate a clear and consistent connection between subacromial space and patient symptoms. This suggests that complex, multiple factors, rather than simply a reduced AHD, may be involved in the development of pain and dysfunction associated with SAPS.

Conclusions

Reduced subacromial space does not appear to be a determining factor in shoulder pain, and there is no clear linear relationship between AHD and symptoms. This challenges some traditional approaches to treating shoulder pain, prompting practitioners to consider other variables when treating their patients.

Source:
Park, S.W., Chen, Y.T., Thompson, L. et al. No relationship between the acromiohumeral distance and pain in adults with subacromial pain syndrome: a systematic review and meta-analysis. Sci Rep 10, 20611 (2020). https://doi.org/10.1038/s41598-020-76704-