Sensorimotor control deficiency in recurrent anterior shoulder instability assessed with a stabilometric force platform Pascal Edouard, MD, PhD a,b,c, *, David Gasq, MD, MSc d , Paul Calmels, MD, PhD b,c , Francis Degache, PhD e a Department of Clinical and Exercise Physiology, Sports Medicine Unit, University Hospital of Saint-Etienne, Faculty of Medicine, Saint-Etienne, France b Laboratory of Exercise Physiology (LPE EA 4338), University of Lyon, Saint-Etienne, France c Department of Physical Medicine and Rehabilitation, University Hospital of Saint-Etienne, Saint-Etienne, France d Department of Functional Physiology Explorations, University Hospital of Toulouse-Rangueil, Toulouse, France e School of Health Sciences, Health Research Unit, University of Applied Sciences Western Switzerland, Lausanne, Switzerland Background: Deficiencies in both afferent proprioceptive information and efferent motor responses have been independently reported in patients with recurrent anterior shoulder instability. We used a vali- dated force platform method to analyze the association between the stabilometric parameters of the upper limb as representative of the shoulder’s sensorimotor control and clinical glenohumeral joint instability. Methods: We enrolled 32 patients with unilateral recurrent anterior post-traumatic shoulder disloca- tion, on the dominant side in 13 patients (DIG) and the non-dominant side in 19 patients (NDIG) and 16 healthy nonathletic subjects (CG). Displacements of the Center of Pressure were measured by a Win-Posturoâ Medicapteurs force platform in the upper limb weight-bearing position with the lower limbs resting on a table up to the anterior superior iliac spines. The association between stabilometric values and clinical shoulder instability was analyzed by side-to-side comparisons and comparisons to a control group. Results: For CG and NDIG, there were no side-to-side differences. For DIG, stabilometric values were significantly higher on the dominant pathological shoulder side than on the healthy contralateral non- dominant side ( P < .01). The percentage of side-to-side differences was higher in DIG than CG (P < .01). Conclusion: Sensorimotor control deficiency was associated with recurrent anterior shoulder in- stability, especially in patients with the pathological shoulder on their dominant side. Using a force platform to assess sensorimotor control of the shoulder is feasible in patients with shoulder instability, and can allow assessment of the global sensorimotor control deficiency present in unstable shoulders. This study was exempt from IRB Ethical Committee approval. *Reprint requests: Pascal Edouard, MD, PhD, Department of Clinical and Exercise Physiology, Sports Medicine Unit, Bellevue Hospital, University Hospital of Saint-Etienne, F-42055 Saint-Etienne Cedex 2, France. E-mail address: Pascal.Edouard42@gmail.com (P. Edouard). J Shoulder Elbow Surg (2013) -, 1-6 www.elsevier.com/locate/ymse 1058-2746/$ - see front matter Ó 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2013.06.005