1 Measurement properties of the Western Ontario Shoulder Instability Index 1 in Dutch patients with shoulder instability 2 3 Just A. van der Linde, MD*, W. Jaap Willems, MD, PhD¶, Derk A. van Kampen, MD, PhD^, 4 Loes W.A.H. van Beers, MSc*, Derek F.P. van Deurzen, MD*, Caroline B. Terwee, PhD§ 5 6 * Department of Orthopaedic Surgery and Traumatology, Onze Lieve Vrouwe Gasthuis, 7 Amsterdam, the...