Question: We have 14 siblings in our family , at least 10 of us has had a frozen shoulder.  We are wondering why?  should we be concerned?

Reference:
 Frozen shoulder - aftercare Adhesive capsulitis - aftercare Frozen shoulder syndrome - aftercare Pericapsulitis - aftercare Stiff shoulder - aftercare Shoulder pain - frozen shoulder Summary A frozen shoulder is shoulder pain that leads to stiffness of your shoulder. Often the pain and stiffness are present all the time. More About Your Injury The capsule of the shoulder joint is made of strong tissue (ligaments) that hold the shoulder bones to each other. When the capsule becomes inflamed, the shoulder bones cannot move freely in the joint. This condition is called frozen shoulder. Frozen shoulder may develop with no known cause. It can also occur in people who: Have thyroid disease, diabetes, or are going through menopause Have a shoulder injury Have had a stroke that makes them unable to use their arm Have a cast on their arm that holds their arm in one position What to Expect Symptoms of frozen shoulder often follow this pattern: At first, you have a lot of pain, which can come on abruptly even without an injury or trauma. Your shoulder can become very stiff and hard to move, even when the pain lessens. It becomes hard to reach over your head or behind you. This is the freezing phase. Finally, the pain goes away and you can use your arm again. This is the thawing phase and can take months to end. It can take a few months to go through each stage of frozen shoulder. The shoulder can get very painful and stiff before it starts to loosen. It can take as long as 18 to 24 months for complete healing. To help speed healing, your health care provider will likely do the following: Teach you exercises to restore motion in your shoulder joint. Refer you to a physical therapist. Prescribe medicines for you to take by mouth. These include drugs to reduce pain and inflammation in the shoulder joint. You may also receive a shot of anti-inflammatory drug or steroid directly into the joint. Most people have a full recovery with full range of motion without surgery. Symptom Relief Using moist heat on your shoulder 3 to 4 times a day may help relieve some pain and stiffness. For pain, you can use ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn), or acetaminophen (Tylenol). You can buy these pain medicines at the store. Talk with your provider before using these medicines if you have heart disease, high blood pressure, kidney disease, or have had stomach ulcers or internal bleeding in the past. DO NOT take more than the amount recommended on the bottle or by your provider. In Your Home Get help setting up your home so that you can get to everything you need without reaching above your shoulders or behind your back. Keep the clothes that you wear most often in drawers and shelves that are between your waist and shoulder level. Store food in cupboards, drawers, and refrigerator shelves that are between your waist and shoulder level. Get help with house cleaning, taking out the garbage, gardening, and other household tasks. DO NOT lift heavy things or do activities that require a lot of shoulder and arm strength. Shoulder Exercises You will learn some simple exercises and stretches for your shoulder. At first, try to do these exercises once every hour, or at least 4 times a day. It is more important to do the exercises often than to do them for a long time each time you do them. Use moist heat before the exercises to help lessen pain and increase movement. The exercises should focus on stretching of the shoulder and range of motion. Avoid exercises to strengthen your shoulder until the range of motion has returned. Some of the exercises are: Shoulder stretches Pendulum Wall crawl Rope and pulley stretches Movements to help with internal and external rotation, such as hand behind back Your doctor or physical therapist will show you how to do these exercises. When to Call the Doctor Call your doctor if: The pain in your shoulder is getting much worse even if you take pain medicine You re-injure your arm or shoulder Your frozen shoulder is making you feel sad or depressed Review Date 4/9/2018 Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. 

Answer: Frozen shoulder may develop with no known cause. It can also occur in people who: - Have thyroid disease, diabetes, or are going through menopause - Have a shoulder injury - Have had a stroke that makes them unable to use their arm - Have a cast on their arm that holds their arm in one position. ...  Most people have a full recovery with full range of motion