Balance ability and postural stability among patients with painful shoulder disorders and healthy controls

Tobias Baierle,Petra Magosch,Thilo Kromer,Hannu Luomajoki,Carmen Petermann

doi:10.1186/1471-2474-14-282

Abstract

BackgroundIn therapeutic settings, patients with shoulder pain often exhibit deficient coordinative abilities in their trunk and lower extremities. The aim of the study was to investigate 1) if there is a connection between shoulder pain and deficits in balance ability and postural stability, 2) if pain intensity is related to balance ability and postural stability, and 3) if there is a connection between body mass index (BMI) and balance ability and postural stability.MethodsIn this case–control study, patients (n = 40) with pathological shoulder pain (> 4 months) were matched with a healthy controls (n = 40) and were compared with regard to their balance ability and postural stability. Outcome parameters were postural stability, balance ability and symmetry index which were measured using the S3-Check system. In addition, the influence of shoulder pain intensity and BMI on the outcome parameters was analysed.ResultsPatients with shoulder pain showed significantly worse results in measurements of postural stability right/left (p < 0.01) and front/back (p < 0.01) as well as balance ability right/left (p = 0.01) and front/back (p < 0.01) compared to healthy controls. There were no significant group differences with regard to symmetry index. However, there was a significant (p < 0.01) symmetry shift towards the affected side within the shoulder pain group. There was no correlation between pain intensity and measurements of balance ability or postural stability. Likewise, no correlation between BMI and deficiencies in balance ability and postural stability was established.ConclusionsPatients with pathological shoulder pain (> 4 months) have deficiencies in balance ability and postural stability; however the underlying mechanisms for this remain unclear. Neither pain intensity nor BMI influenced the outcome parameters. Patients with shoulder pain shift their weight to the affected side. Further research is needed to determine if balance training can improve rehabilitation results in patients with shoulder pathologies.

Highlights

In therapeutic settings, patients with shoulder pain often exhibit deficient coordinative abilities in their trunk and lower extremities
The aim of this study was to investigate 1) if there is a connection between shoulder pain and deficits in balance ability and postural stability, 2) if pain intensity is related to balance ability and postural stability, and 3) if there is a connection between body mass index and balance ability and postural stability
The study shows that moderate to severely-rated painful shoulder pathologies are accompanied by deficits in balance ability and postural stability

Summary

Introduction

Patients with shoulder pain often exhibit deficient coordinative abilities in their trunk and lower extremities. Treede et al suggest that pain processing may cause balance disorders [5] One explanation for this could be the fact that pain processing, the balance control circuit [5] and the inhibition of muscles caused by pain share some pathways of the central nervous system [6]. Carpa and Ro showed that pain in the masticatory muscles can alter the central modulation, which in turn, influences the proprioceptive muscle spindles [9]. These muscular inhibition mechanisms due to pain might have a negative effect on balance ability

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