Association between the side of unilateral shoulder pain and preferred sleeping position: a cross-sectional study of 83 Danish patients.

OBJECTIVE

The purpose of this study was to evaluate if there is an association between the side of unilateral shoulder pain and the patient's preferred sleeping position and if the preferred sleeping position is related to which side of a double bed one lies in.

METHODS

In a cross-sectional study, adult patients seeking chiropractic care with unilateral shoulder pain were asked about sleeping position and, if sleeping with a partner, which side of the bed they slept in. A total of 83 participants were included from 10 chiropractic clinics. Associations were cross-tabulated and tested by Fisher exact test.

RESULTS

The pain was in the right shoulder in 55% (95 % confidence interval, 46-66) of the participants with unilateral pain. The side of shoulder pain was associated to the side patients slept on, with 67% of those sleeping on one side lying on the painful shoulder (P = .02). Moreover, patients were more likely to turn away from their partner at night, and 76% slept on the side opposite their partner (P < .001).

CONCLUSIONS

Patients with unilateral shoulder pain were more likely to sleep on the side of the painful shoulder than on the pain-free side and reported to turn away from their partners in bed. It is unknown whether the observed associations are causal, but it is worth investigating whether a change in sleeping position has a positive effect on patients with shoulder pain and if this can be achieved simply by changing side of sleeping in bed.