Subacromial pressures vary with simulated sleep positions

Rotator Cuff Tears Are Related to the Side Sleeping Position

Purpose

To determine whether there was a relationship between sleep position and symptomatic partial- and full-thickness rotator cuff tears.

Methods

A consecutive series of patients that met the inclusion/exclusion criteria (n = 58) were in seen in clinic between July 2019 and December 2019. All of these individuals had a significant partial-thickness (> 50%) or full-thickness rotator cuff tear determined by either ultrasound, magnetic resonance imaging, or both. All patients in this series either had an insidious onset of shoulder pain or their symptoms were related to the basic wear and tear of daily activities. Traumatic rotator cuff tears (those associated with a significant traumatic event such as shoulder instability, motor vehicle accidents, sports related injuries, etc.) were excluded. Previous shoulder surgery, recurrent rotator cuff tears, and worker's compensation cases also were excluded from this series. As part of the history-taking process, the patients were asked what was their preferred sleeping position-side sleeper, back sleeper, or stomach sleeper. A χ2 test was conducted to determine the relationship between rotator cuff pathology and sleep position.

Results

Of the 58 subjects, 52 of the patients were side sleepers, 4 were stomach sleepers, 1 was a back sleeper, and 1 preferred all 3 positions. Statistical analysis, using the χ2 test (P < .0001), demonstrated that rotator cuff tears were most often seen in side sleepers.

Conclusions

In our study, there appeared to be a relationship between the preference of being a side sleeper and the presence of a rotator cuff tear.

Level of Evidence

Level IV, prognostic case series.

Coexistence of Cervical Disc Herniation and Shoulder Soft Tissue Pathologies and the Effect of Sleeping Positions and Orthopedic Pillows

Background/aim This study investigates the degree of coexistence of cervical disc herniation and shoulder soft tissue pathology, as well as the effect of sleeping positions and orthopedic pillow use. Materials and methods This present study was conducted on 72 patients with shoulder/arm pain operated on for cervical disc herniation. Two groups were examined according to the presence of shoulder soft tissue pathology, four common sleeping positions, and the use of an orthopedic pillow. Preoperative and postoperative shoulder/arm visual analog scale (VAS) scores were compared. Results The preoperative VAS values were 7.35, while the postoperative VAS values were 3.32. Twenty-one patients (29.2%) had a disc at the C3-4 level, a rate equal to that for the C5-6 level. Twenty-four patients (33.3%) had a disc at the C4-5 level. Thirty-two cases (44.4%) slept in a side-lying position on the same side as their disc herniation. Among those with a herniated disc at the C3-4 level, 8 (53.3%) preferred sleeping side-lying on the opposite side of the disc. In contrast, those with a herniated disc at the C4-5 level more frequently (40.6%) slept side-lying on the same side as the disc. Mean VAS scores were significantly higher in cases with shoulder soft tissue pathology and were significantly lower in the group that used orthopedic pillows (p<0.001). Conclusion Shoulder soft tissue pathologies should be considered in postoperative shoulder pain. The use of orthopedic pillows is effective in preoperative and postoperative pain. Sleeping positions do not affect the shoulder/arm pain before and after the operation, but they affect the level of cervical disc herniations.

The Effects of Body Positions and Abduction Angles on Shoulder Muscle Activity Patterns during External Rotation Exercises

BACKGROUND

Excess and repetitive glenohumeral external rotation (ER) is at a higher risk for shoulder injuries, which occurs frequently in professional sports and specific occupations. Current rehabilitation programs emphasize selective targeting of muscle activity, which can help restore dysfunctional muscle imbalances or prevent injuries. However, the impact of different body postures on GH muscle activity during ER exercises has not been fully understood. Therefore, the purpose of this study was to investigate shoulder EMG activity for different body positions and humeral abduction angles during ER exercises.

METHOD

Twenty-three healthy young men (age: 22.3 ± 2.3, height: 175.75 ± 4.02, mass: 75.37 ± 9.14) participated in this study. Surface Electromyography was recorded from seven shoulder muscles: upper trapezius, lower trapezius, serratus anterior, infraspinatus, and deltoid. Six ER exercises: three postures (sitting, supine lying, and prone lying) and two abduction angles (ABD; 45° and 90°) were tested using an isokinetic dynamometer.

RESULTS

During a sitting position, the lower trapezius/upper trapezius muscle activity ratios were significantly increased for sitting compared to supine lying and prone lying (p < 0.001, p = 0.004). Serratus anterior/upper trapezius co-contraction indices were significantly increased for 90° than 45° ABD (p < 0.001).

CONCLUSION

These findings can provide insight into new training programs aimed at restoring GH muscle imbalances.

Does your sleeping position affect your shoulder pain?

Aim: This study aimed to evaluate patients with shoulder pain according to their sleeping positions based on their clinical and magnetic resonance imaging (MRI) findings and to determine possible factors affecting shoulder pain. Material and Method: A total of 115 patients were included in the study. The severity of shoulder pain was evaluated with the visual analog scale (VAS), shoulder function was evaluated with the simple shoulder test, and the ability to perform physical activities was evaluated with the QuickDASH questionnaire. The biceps tendon, rotator cuff (RC), subacromial-subdeltoid bursa, glenohumeral joint (GHJ), and acromioclavicular joint (ACJ) were evaluated using MRI. Results: Of the patients with shoulder pain, 66.1% were female, 50.4% were primary school graduates, 53.9% were housewives, and 41.7% had a systemic disease. The mean age of the patients was 50.48±13.61 years while the median BMI and VAS values were 26.1 (18.2-41.4) and 8 (2-10), respectively. Considering the sleeping positions, it was found that 39.1% (most common) of the patients were sleeping in the fetus position, and considering the results of patients’ MRI examinations, the most common problem was related to the pathologies of the supraspinatus tendon (42.6%). It was found that sleep quality, which was poor in all patients, was worse in females (p=0.311), in those over 50 years of age (p=0.007), and those with a systemic disease (0.325). It was discovered that Pittsburgh's sleep quality index score was generally worse in those who slept in the soldier position and in the log position (p>0.05). The rates of pathologies of the supraspinatus tendon were found to be the highest in those that slept in the fetus position (p=0.931). It was also found that the rates of impingement, bicipital tendinitis, combined problems, and adhesive capsulitis did not differ significantly according to sleeping positions. Although occupational variables for supraspinatus degeneration remained significant in the model, having a desk job statistically significantly increased the probability of supraspinatus degeneration by 3.38 times when compared to being a housewife (95% CI=1.143-9.996; p=0.028) and it was identified that the probability of acromioclavicular degeneration increased by 1.16 times for every 1-unit increase in BMI. Conclusion: Different sleeping positions may predispose to different shoulder pathologies and shoulder pain, and shoulder pathologies may lead to deterioration of sleep quality, especially in older patients. For this reason, suggesting correct and appropriate sleeping positions may be a useful treatment method in reducing pain and disability and increasing sleep quality.

Shoulder Surgery as an Effective Treatment for Shoulder-Related Sleep Disturbance: A Systematic Review

PURPOSE

The purpose of this systematic review is to evaluate the current literature in an effort to investigate sleep quality and disturbances and the association with clinical outcomes of patients undergoing shoulder surgery.

METHODS

A systematic review of the PubMed, Embase, and Cochrane Library databases was performed according to PRISMA guidelines. All English-language literature reporting clinical outcomes and sleep quality and disturbance after shoulder surgery was reviewed by 2 independent reviewers. Outcomes assessed included patient-reported outcomes (PROs) and sleep quality. Specific PROs included the Pittsburgh Sleep Quality Index (PSQI), Visual Analog Scale (VAS) for pain, Simple Shoulder Test (SST), University of California Los Angeles (UCLA) Shoulder Rating Scale, and American Shoulder and Elbow Surgeons Score (ASES). Study methodology was assessed using the Modified Coleman Methodology Score. Descriptive statistics are presented.

RESULTS

Sixteen studies (11 level IV, 2 level III, 3 level II) with a total of 2748 shoulders were included (age, 12-91 years; follow-up, 0.25-132 months). In total, 2198 shoulders underwent arthroscopic rotator cuff repair (RCR), 131 shoulders underwent arthroscopic capsular release, 372 shoulders underwent total shoulder arthroplasty (TSA), 18 shoulders underwent comprehensive arthroscopic management, and 29 shoulders underwent sternoclavicular joint procedures. All shoulder surgeries improved self-reported sleep and PROs from before to after surgery. In RCR patients, PSQI scores were significantly associated with VAS scores, SST scores (r = 0.453, r = -0.490, P < .05, respectively), but not significantly associated with UCLA Shoulder rating scale or the ASES scores (r = 0.04, r = 0.001, P > .05, respectively). In TSA patients, PSQI scores were significantly associated with ASES scores (r = -0.08, P < .05). All 4 RCR studies and 1 TSA study using PSQI found significant improvements in mean PSQI scores within 6 to 24 months (P < .05).

CONCLUSIONS

Surgical intervention for rotator cuff tear and glenohumeral osteoarthritis significantly improves self-reported sleep in patients with shoulder pain. However, there remains a dearth of available studies assessing the effects of surgical intervention for adhesive capsulitis, sternoclavicular joint instability, and sternoclavicular osteoarthritis on sleep. Future studies should use sleep-specific PROs and quantitative measures of sleep to further elucidate the relationship between sleep and the effect of shoulder surgery.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II-IV studies.

Editorial Commentary: Sleep Disorders in Rotator Cuff Diseases

One of the most common complaints expressed by patients with rotator cuff disease is poor-quality sleep. Sleeping significantly affects daily life, influencing biological functions, learning, memory, and cognitive processes. The etiology of nocturnal shoulder pain is controversial, yet there is a consensus that high levels of proinflammatory factors and pain-related cytokines are involved in the pathogenesis of this disturbance in patients with shoulder rotator cuff pathology. Unfortunately, many variables, including body mass index, depression, sex, low back pain, cervical pain, diabetes, narcotics, pain, pain perception, and sleeping position (which may influence tendon perfusion), could influence sleep quality in both healthy patients and patients with rotator cuff pathology. For now, it is not possible to assess the real influence of rotator cuff repair surgery on sleep quality improvement.

Arthroscopic Rotator Cuff Repair Improves Sleep Disturbance and Quality of Life: A Prospective Study

Sleep disturbances are very common in patients with rotator cuff injury. Improvement of sleep quality in these patients can be considered a significant factor for healing in conjunction with surgery. The primary objective of this prospective study was to evaluate changes in sleep quality after surgery in patients with rotator cuff repair by analyzing the PSQI (Pittsburgh Sleep Quality Index) score. The secondary aim was to evaluate the improvement in quality of life in terms of functional limitations and shoulder pain after surgery. Fifty-eight patients with rotator cuff tears treated by arthroscopic surgery were included. All the patients completed the PSQI, the 36-Item Short Form Survey (SF-36), the Simple Shoulder Test (SST), the American Shoulder and Elbow Surgeons Shoulder Score (ASES), the Oxford Shoulder Score (OSS) and the Constant-Murley Score (Constant) before and at one, three and six months after surgery. Overall improvement in all the scores analyzed (p < 0.001) was found. Preoperative and postoperative PSQI scores correlated with SF-36, SST, ASES and Constant scores at each follow-up. Preoperative and one-month postoperative OSS correlated with the PSQI score. Using the Friedman test, we found an overall improvement in all score analyses (p < 0.001). The results prove that after rotator cuff repair, sleep disturbances improve three to six months after surgery improving the quality of life of these patients.

Evaluation of three-dimensional acromiohumeral distance in the standing position and comparison with its conventional measuring methods

Background

Narrowing of the acromiohumeral distance (AHD) implies a rotator cuff tear. However, conventional AHD measurements using two-dimensional (2D) imaging or with the patient in the supine position might differ from that while standing during daily activity. This study aimed to evaluate the three-dimensional (3D) actual distance between the acromion and humeral head in the standing position and compare the AHD values with those obtained using conventional measuring methods.

Methods

Computed tomography (CT) images of 166 shoulders from 83 healthy volunteers (31 male and 52 female; mean age 40.1 ± 5.8 years; age range, 30–49 years) were prospectively acquired in the supine and standing positions using conventional and upright CT scanners, respectively. The minimum distance between the acromion and humeral head on the 3D surface models was considered as the 3D AHD. We measured the 2D AHD on anteroposterior digitally reconstructed radiographs. The AHD values were compared between the supine and standing positions and between the 2D and 3D measurements.

Results

The mean values of 2D AHD were 8.8 ± 1.3 mm (range, 5.9–15.4 mm) in the standing position and 8.1 ± 1.2 mm (range, 5.3–14.3 mm) in the supine position. The mean values of 3D AHD were 7.3 ± 1.4 mm (range, 4.7–14.0 mm) in the standing position and 6.6 ± 1.2 mm (range, 4.4–13.7 mm) in the supine position. The values of 3D AHD were significantly lower than those of 2D AHDs in both the standing and supine positions (P < 0.001). The values of 2D and 3D AHDs were significantly lower in the supine position than in the standing position (P < 0.001).

Conclusions

This study evaluated the 3D AHD of normal shoulders in the standing position using an upright CT scanner. The present results indicated that assessments in the supine position can underestimate the value of the AHD compared with those made in the standing position and that assessments using 2D analysis can overestimate the value.

Sleep Disturbance and Rotator Cuff Tears: A Systematic Review

Background and Objectives: Sleep disorders are one of the most common complaints of patients with rotator cuff (RC) tears. However, potential correlations between the treatment of RC tears and the causal factors of sleep disorders are still under discussion. The aim of this review is to evaluate quality of sleep in patients before and after surgery for RC tears and to identify which factors affected patients’ sleep. Materials and Methods: A systematic review was conducted. To provide high quality of the review, the included studies were evaluated with the standardized tool “Quality Assessment Tool for Quantitative Studies” developed by the Effective Public Health Practice Project. Results: The search strategy yielded 78 articles. After duplicate removal and titles, abstracts and full-texts review, four studies were included in the systematic review. Concerning shoulder function, the most frequently reported scale was the Simple Shoulder Test (SST). Regarding sleep quality, the most frequently reported score was the Pittsburgh Sleep Quality Index (PSQI). Conclusion: We found that the majority of patients with RC tears had a sleep disturbance, especially before surgery with a general improvement in sleep quality post-operatively. Moreover, sleep quality was correlated with pain and it also seems that factors as comorbidities, obligatory position during night time, preoperative and prolonged postoperative use of narcotics and psychiatric issues may play an important role in sleep quality.

Is sleep position associated with glenohumeral shoulder pain and rotator cuff tendinopathy: a cross-sectional study

BACKGROUND

Glenohumeral pain and rotator cuff tendinopathy (RCT) are common musculoskeletal complaints with high prevalence among working populations. The primary proposed pathophysiologic mechanisms are sub-acromial RC tendon impingement and reduced tendon blood flow. Some sleep postures may increase subacromial pressure, potentially contributing to these postulated mechanisms. This study uses a large population of workers to investigate whether there is an association between preferred sleeping position and prevalence of: (1) shoulder pain, and (2) rotator cuff tendinopathy.

METHODS

A cross-sectional analysis was performed on baseline data from a multicenter prospective cohort study. Participants were 761 workers who were evaluated by questionnaire using a body diagram to determine the presence of glenohumeral pain within 30 days prior to enrollment. The questionnaire also assessed primary and secondary preferred sleep position(s) using 6 labeled diagrams. All workers underwent a structured physical examination to determine whether RCT was present. For this study, the case definition of RCT was glenohumeral pain plus at least one of a positive supraspinatus test, painful arc and/or Neer's test. Prevalence of glenohumeral pain and RCT were individually calculated for the primary and secondary sleep postures and odds ratios were calculated.

RESULTS

Age, sex, Framingham cardiovascular risk score and BMI had significant associations with glenohumeral pain. For rotator cuff tendinopathy, increasing age, Framingham risk score and Hand Activity Level (HAL) showed significant associations. The sleep position anticipated to have the highest risk of glenohumeral pain and RCT was paradoxically associated with a decreased prevalence of glenohumeral pain and also trended toward being protective for RCT. Multivariable logistic regression showed no further significant associations.

CONCLUSION

This cross-sectional study unexpectedly found a reduced association between one sleep posture and glenohumeral pain. This cross-sectional study may be potentially confounded, by participants who are prone to glenohumeral pain and RCT may have learned to avoid sleeping in the predisposing position. Longitudinal studies are needed to further evaluate a possible association between glenohumeral pain or RCT and sleep posture as a potential risk factor.

A lightweight sensing platform for monitoring sleep quality and posture: a simulated validation study

Background

The prevalence of self-reported shoulder pain in the UK has been estimated at 16%. This has been linked with significant sleep disturbance. It is possible that this relationship is bidirectional, with both symptoms capable of causing the other. Within the field of sleep monitoring, there is a requirement for a mobile and unobtrusive device capable of monitoring sleep posture and quality. This study investigates the feasibility of a wearable sleep system (WSS) in accurately detecting sleeping posture and physical activity.

Methods

Sixteen healthy subjects were recruited and fitted with three wearable inertial sensors on the trunk and forearms. Ten participants were entered into a ‘Posture’ protocol; assuming a series of common sleeping postures in a simulated bedroom. Five participants completed an ‘Activity’ protocol, in which a triphasic simulated sleep was performed including awake, sleep and REM phases. A combined sleep posture and activity protocol was then conducted as a ‘Proof of Concept’ model. Data were used to train a posture detection algorithm, and added to activity to predict sleep phase. Classification accuracy of the WSS was measured during the simulations.

Results

The WSS was found to have an overall accuracy of 99.5% in detection of four major postures, and 92.5% in the detection of eight minor postures. Prediction of sleep phase using activity measurements was accurate in 97.3% of the simulations. The ability of the system to accurately detect both posture and activity enabled the design of a conceptual layout for a user-friendly tablet application.

Conclusions

The study presents a pervasive wearable sensor platform, which can accurately detect both sleeping posture and activity in non-specialised environments. The extent and accuracy of sleep metrics available advances the current state-of-the-art technology. This has potential diagnostic implications in musculoskeletal pathology and with the addition of alerts may provide therapeutic value in a range of areas including the prevention of pressure sores.

Electronic supplementary material

The online version of this article (10.1186/s40001-018-0326-9) contains supplementary material, which is available to authorized users.

Sleep Quality in Patients With Rotator Cuff Disease

BACKGROUND

Little is known about the influence of rotator cuff pathology on sleep. The purpose of this study was to determine which patient-reported factors correlate with sleep disturbance in patients with rotator cuff disease.

METHODS

A nonrandomized, cross-sectional cohort study was performed to evaluate the effects of rotator cuff disease on sleep quality. Data collected at time zero (before any treatment) included the Single Assessment Numeric Evaluation rating, the American Shoulder and Elbow Surgeons score, the Pittsburgh Sleep Quality Index, patient demographics, and medical comorbidities. Statistical analysis included the Pearson correlation and multiple regression analysis to determine which patient-reported factors were associated with sleep disturbance.

RESULTS

Nocturnal pain was reported by 91% of the 391 participants (274 with tendinitis and 117 with rotator cuff tears). Participants had a mean age of 57 years. Pearson correlation coefficients determined that poor sleep quality in one group or both the tendinitis and the rotator cuff tear groups was associated with higher pain visual analog scale scores (0.27 and 0.31; P = 0.004 and P < 0.0001, respectively), depression (0.27 and 0.30; P < 0.01), female sex (0.24 and 0.27; P < 0.001), presence of low back pain (0.25 and 0.27; P < 0.01), diabetes mellitus (0.24 in the rotator cuff tear group; P < 0.01), and increased body mass index (0.22 and 0.27; P = 0.02).

DISCUSSION

The status of the rotator cuff did not correlate with increasing symptoms of shoulder pain or with worse sleep quality as measured by the Pittsburgh Sleep Quality Index. These results support the theory that worsening symptoms of shoulder pain may not be clearly associated with rotator cuff disease severity.

CONCLUSION

Worse sleep quality scores in patients with rotator cuff disease are associated with pain, depression, female sex, low back pain, diabetes mellitus, and high body mass index. Overall, sleep quality did not differ among patients with varying rotator cuff disease severity. Only hypertension (in patients with rotator cuff tears) and concurrent cervical pathology (in patients with tendinitis) were uniquely related to the disease classification. Further investigation is needed to better define how these factors interact and influence nocturnal shoulder pain and sleep quality in patients with rotator cuff disease.

LEVEL OF EVIDENCE

Level III prognostic cohort study.

Electromyographic activities of the subscapularis, supraspinatus and infraspinatus muscles during passive shoulder and active elbow exercises

PURPOSE

Postoperative exercises may increase load on repaired tendons. Differences in the activity of the rotator cuff muscles were assessed during several different types of passive shoulder and active elbow exercises.

METHODS

In 15 healthy subjects, passive forward flexion of the shoulder was performed using a table, pulley and rope, and a cane, and external rotation was performed using a cane and a wall. The active elbow flexion-extension exercise was also performed while holding the upper arm with the contralateral hand. Activation amplitudes of the supraspinatus, infraspinatus and subscapularis muscles were evaluated using electromyography with fine wires.

RESULTS

During passive forward flexion, the supraspinatus and infraspinatus muscles exhibited lower activity when using a table compared with a cane (both P < 0.01) and a pulley and rope (both P < 0.05). Flexion of <90° decreased supraspinatus activation compared with 170° (P = 0.047). During external rotation of the shoulder while using the cane and wall, there was no difference in the activity of any muscles. Electromyographic activity during the active elbow exercise was lower in the supraspinatus while holding the upper arm (P = 0.018).

CONCLUSION

The table sliding exercise may reduce stress on the rotator cuff during passive forward flexion more than the other exercises do. Decreasing the range of motion to less than 90° in forward flexion activated the supraspinatus less. Moreover, movement of the elbow can be performed holding the upper arm to activate the rotator cuff to a lesser extent.

LEVEL OF EVIDENCE

Prognostic study, Level II.

Increased blood flow in the anterior humeral circumflex artery correlates with night pain in patients with rotator cuff tear

BACKGROUND

Night pain is a particularly vexing symptom in patients with rotator cuff tear. It disturbs sleep and decreases quality of life, and there is no consensus regarding its etiology. Based on arthroscopic surgical observations of synovitis around the rotator interval or capsule surface in rotator cuff tear, we hypothesized that blood flow from the artery feeding the capsule increases blood supply to the synovium. This study aimed to investigate the relationship between blood flow and night pain using pulse Doppler ultrasonography.

METHODS

A series of 47 consecutive patients with rotator cuff tear was evaluated. The peak systolic velocity and resistance index of blood flow in the ascending branch of the anterior humeral circumflex artery were evaluated using pulse Doppler ultrasonography. We also investigated 20 normal shoulders in healthy volunteers. The peak systolic velocity and resistance index were compared between affected and unaffected sides in patients and between dominant and nondominant sides in controls.

RESULTS

Anterior humeral circumflex artery peak systolic velocity and resistance index did not differ between sides in control subjects or in patients with rotator cuff tear without night pain. However, anterior humeral circumflex artery peak systolic velocity and resistance index did differ significantly between sides in patients with rotator cuff tear with night pain.

CONCLUSIONS

This study revealed anterior humeral circumflex artery hemodynamics in patients with rotator cuff tear and normal subjects using Doppler ultrasonography. Night pain, particularly involving aching, appears to be related to the hemodynamics. These findings suggest that investigating the hemodynamics of patients with rotator cuff tear with night pain may lead to greater understanding of the etiology of this symptom.

A New Definition of BMI Scale by Relationship between Respiration and Unconscious Behavior during Sleep with Body Motion Wave

Recently, health problems due to overwork, apparent suicide produced by the progress of the social stress and lifestyle diseases and lifestyle diseases like hyperpiesia or obesity have been reported. From this, it has become of interest to avoid these problems and to keep the health. However, the indicators for health control and physical condition haven't been defined. Body Mass Index (BMI) has traditionally been used as an indicator of health. But, there are many unclear points left in the criteria of BMI to utilize. Sleep would be an important theme to know and to keep health. During sleep, the biological information related to health state would be appeared because of predominant activity of autonomic nervous system under the state of unconsciousness. From these, the authors investigated the relationship between BMI and autonomic nervous activity. Nineteen healthy young adults participated in this study and performed sleep experiment by adopting a pressure sensor named “dynamic air-pressure sensor” and a pressure sensor array. As a result, the authors found some relationships among respiration state, motions of muscles and unconscious behavior depending on BMI. This result about sleep behavior would suggest a new definition for BMI. For example, large value of BMI brings influences, maybe bad, to respiratory behavior during sleep.

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.