WOSI · Western Ontario Shoulder Instability Index

The instability measure, and the reason a shoulder-instability page needs its own PROM. Twenty-one items across four domains — physical symptoms, sport and recreation, lifestyle, and emotions.

The emotions domain is the point. Instability is a confidence problem as much as a mechanical one, and no general shoulder score captures that.

Any instability presentation — anterior, posterior or multidirectional — at baseline, at return-to-sport decisions, and after surgery.

Do not substitute SPADI here. Instability patients frequently score well on daily-living items while remaining unable to trust the shoulder.

Each item is a 100 mm visual analogue, summed to 0–2100, usually reported as a percentage of normal. Lower is better.

The raw total is unwieldy — report the percentage.

Range, strength, or apprehension on examination. It is a quality-of-life measure — pair it with your objective findings and a Beighton score.

Interpret against baseline.

Read the four domains. A patient whose physical symptoms have settled while the emotions domain hasn't is exactly the patient who redislocates, and it is the same principle the patellar instability page teaches with its confidence rating.