56 year old male from Michigan presenting with chief complaint of "frozen shoulder". Patient does not have much pain however doing daily tasks such as washing hair is getting more difficult due to loss of range of motion. His past medical history is positive for fracture of left shoulder as a younger man. On the exam patient shows some atrophy of left shoulder muscles.

Discussion:

Muscle atrophy also known as Muscle wasting Is common in arthritis and is usually due to loss of muscle tissue which could be caused by disease or lack of use. Mostly it is caused from disuse. Some of the other causes of atrophy are:

• diabetes (diabetic neuropathy)

• burns

• poliomyelitis

• amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease)

• Guillain-Barre syndrome

• muscular dystrophy

• myotonia congenita

• myotonic dystrophy

• some atrophy that occurs normally with aging

• cerebrovascular accident (stroke)

• spinal cord injury

• peripheral nerve injury (peripheral neuropathy)

• prolonged immobilization

• rheumatoid arthritis

• prolonged corticosteroid therapy