Autonomic Nervous System Function and Central Pain Processing in People With Frozen Shoulder: A Case-control Study.

OBJECTIVES: The pathophysiology of a frozen shoulder (FS) is thought to be related to chronic inflammation. Chronic inflammation may disturb the immune system and consequently the nervous system as part of an overarching system. The aim of this study was to determine the presence of disturbed autonomic nervous system function and altered central pain processing (CPP) in patients with FS. Secondarily, the presence of psychological variables (catastrophizing and hypervigilance) and self-reported associated symptoms of altered CPP in patients with FS were investigated. METHODS: Patients with FS and healthy controls completed the Composite Autonomic Symptom Score (autonomic function) and underwent quantitative sensory testing to assess tactile sensitivity (ie, allodynia), pressure pain thresholds (PPTs, ie, hyperalgesia), temporal summation of pain, and Conditioned Pain Modulation (CPM). Psychological issues were explored with the Pain Catastrophizing Scale and the Pain Vigilance and Awareness Questionnaire, and self-reported symptoms associated with altered CPP were determined with the Central Sensitization Inventory. RESULTS: Thirty-two patients with FS and 35 healthy controls were analyzed in the study. Patients with FS showed more self-reported autonomic symptoms and symptoms of altered CPP, higher levels of pain catastrophizing and hypervigilance, and are more sensitive to tactile touches and mechanical pressure compared with controls. DISCUSSION: On the basis of the effect sizes, between-group differences in allodynia, hyperalgesia, catastrophizing, and hypervigilance were clinically relevant, but only local allodynia, hyperalgesia, catastrophizing, and hypervigilance were statistically different. Therefore, obvious altered CPP was not present at the group level in patients with FS compared with controls.

Personal influencing factors for pressure pain threshold in healthy people: A systematic review and meta-analysis.

All studies that investigated personal factors influencing pressure pain threshold (PPT) in healthy people were synthesized. Data was summarized, and risk of bias (RoB) and level of evidence were determined. Results were pooled per influencing factor, grouped by body region and included in meta-analyses. Fifty-four studies were eligible. Five had low, nine moderate, and 40 high RoB. Following meta-analyses, a strong conclusion was found for the influence of scapular position, a moderate for the influence of gender, and a weak for the influence of age (shoulder/arm region) and blood pressure on PPT. In addition, body mass index, gender (leg region), alcohol consumption and pain vigilance may not influence PPT. Based on qualitative summary, depression and menopause may not influence PPT. For other variables there was only preliminary or conflicting evidence. However, caution is advised, since the majority of included studies showed a high RoB and several were not eligible to include in meta-analyses. Heterogeneity was high in the performed meta-analyses, and most conclusions were weak. More standardized research is necessary.

Exercise Therapy Is Effective for Improvement in Range of Motion, Function, and Pain in Patients With Frozen Shoulder: A Systematic Review and Meta-analysis.

OBJECTIVE(S): To determine (1) the effect of exercise therapy alone or in combination with other interventions compared with solely exercises and programs with or without exercises and (2) what kind of exercise therapy or combination with other interventions is most effective. DATA SOURCES: PubMed, Web of Science and Cochrane Central Register of Controlled Trials. STUDY SELECTION: Studies were screened in a 2-phase approach by 2 independent reviewers (M.M. and L.M.). Reference lists of included studies and interesting systematic reviews were hand searched. DATA EXTRACTION: Two independent reviewers (M.M. and L.M.) extracted information about origin, characteristics of study participants, eligibility criteria, characteristics of interventions, outcome measures and main results in a pre-defined template. DATA SYNTHESIS: Thirty-three studies were included in the qualitative and 19 in the meta-analysis. Preliminary evidence was found for supervised exercises to be more beneficial than home exercises for ROM and function. Multimodal programs comprising exercises may result in little to no difference in ROM compared to solely exercises. Programs comprising muscle energy techniques show little to no difference in ROM when compared with programs with other exercises. Adding stretches to a multimodal program with exercises may increase ROM. There is uncertain evidence that there is a difference between those programs regarding function and pain. Preliminary evidence was found for several treatment programs including exercises to be beneficial for improvement in both passive and active ROM, function, pain, and muscle strength. No studies used patient satisfaction as an outcome measure. CONCLUSIONS: ROM, function, and pain improve with both solely exercises and programs with exercises, but for ROM and pain there was little to no difference between programs and for function the evidence was uncertain. Adding exercises improve active ROM compared with a program without exercises, whereas adding physical modalities has no beneficial effect. Muscle energy techniques are a beneficial type of exercise therapy for improving function compared with other types of exercise. Unfortunately, no conclusion can be drawn about the results in the long-term and most effective dose of exercise therapy.

Specific versus Non-Specific Exercises for Chronic Neck or Shoulder Pain: A Systematic Review.

The current systematic review aimed to compare the effect of injury-focused (specific) exercises versus more general (non-specific) exercises on pain in patients with chronic neck or shoulder pain. We searched PubMed, EMBASE, and Web of Science. Two reviewers screened and selected studies, extracted outcomes, assessed risk of bias, and rated the quality of evidence. A total of nine eligible studies, represented in 13 articles, were identified, with a considerable risk of bias. One article investigated the acute effect of single bouts of exercise on pain and reported an immediate pain reduction after non-specific exercise. Regarding short-term effects, seven out of the nine studies found no differences in pain between interventions, with inconsistent results among two other studies. Concerning the long-term effects, while pain reduction seems to be favored by specific exercises (two out of four articles), the best format is still unclear. Based on the acute effects, a single bout of non-specific exercise seems to be a better option for pain-relief for patients with chronic neck or shoulder pain. For short-term effects, there are no differences in pain between specific and non-specific exercises. Regarding long-term effects, specific exercises seem to be the best option. Nevertheless, more studies are warranted.