Frozen Shoulder and Glucose Following Corticosteroid Injection

The goal of this clinical study is to look at what happens to blood sugar levels in people who have a frozen shoulder, who do not have diabetes after a corticosteroid injection in people with frozen shoulder. * The primary aim of this study will be to evaluate alterations in glucose levels for people without diabetes, following corticosteroid injection for frozen shoulder. * The secondary aims are to observe a range of clinical, physiological, and psychosocial outcomes following corticosteroid injection for people with frozen shoulder. Participants will wear a glucose measuring device, attached to the upper arm collecting readings of glucose levels for 14 days. Participants will undergo a corticosteroid injection as part of usual care.