Objective Assessment of shoulder mobility with a new 3D gyroscope - a validation study

BMC Musculoskeletal Disorders

Research Article

Stefan Lakemeier¹  Thomas J Heyse¹  Susanne Fuchs-Winkelmann¹  Markus D Schofer¹  Annett Heidrich¹  Turgay Efe¹  Bilal Farouk El-Zayat¹  Udo Wolf²  Nina Timmesfeld³ 

[1] Department of Orthopaedics and Rheumatology, University Hospital Marburg, 35033, Baldingerstrasse, Marburg, Germany;Department of Physiotherapy, University Hospital Marburg, 35033, Baldingerstrasse, Marburg, Germany;Institute for Medical Biometry and Epidemiology, Philipps University Marburg, Bunsenstraße 3, 35037, Marburg, Germany;

关键词: Shoulder Joint;    Medial Position;    Isokinetic Dynamometer;    Simple Shoulder Test;    Shoulder Mobility;   

DOI  :  10.1186/1471-2474-12-168

 received in 2010-11-30, accepted in 2011-07-21,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundAssessment of shoulder mobility is essential for clinical follow-up of shoulder treatment. Only a few high sophisticated instruments for objective measurements of shoulder mobility are available. The interobserver dependency of conventional goniometer measurements is high. In the 1990s an isokinetic measuring system of BIODEX Inc. was introduced, which is a very complex but valid instrument. Since 2008 a new user-friendly system called DynaPort MiniMod TriGyro ShoulderTest-System (DP) is available. Aim of this study is the validation of this measuring instrument using the BIODEX-System.MethodsThe BIODEX is a computerized robotic dynamometer used for isokinetic testing and training of athletes. Because of its size the system needs to be installed in a separated room. The DP is a small, light-weighted three-dimensional gyroscope that is fixed on the distal upper patient arm, recording abduction, flexion and rotation. For direct comparison we fixed the DP on the lever arm of the BIODEX. The accuracy of measurement was determined at different positions, angles and distances from the centre of rotation (COR) as well as different velocities in a radius between 0° - 180° in steps of 20°. All measurements were repeated 10 times. As satisfactory accuracy a difference between both systems below 5° was defined. The statistical analysis was performed with a linear regression model.ResultsThe evaluation shows very high accuracy of measurements. The maximum average deviation is below 2.1°. For a small range of motion the DP is slightly underestimating comparing the BIODEX, whereas for higher angles increasing positive differences are observed.The distance to the COR as well as the position of the DP on the lever arm have no significant influence. Concerning different motion speeds significant but not relevant influence is detected. Unfortunately device related effects are observed, leading to differences between repeated measurements with any two different devices up to 8° at maximal range of motion (180°).ConclusionsIn summary the results shows high correlation and good reproducibility of measurements. All deviations are inside the tolerance interval of 5°, if one device is used. An unlikely systematic device effect is detected. These laboratory trials are promising for the validation of this system in humans. The challenge for both systems will be the changing of the COR in the shoulder joint at elevations higher than 90°.

【 授权许可】

CC BY   
© El-Zayat et al; licensee BioMed Central Ltd. 2011