How Diabetes Affects Your Muscles, Joints, and Tendons
By Stephen Bunting, Specialist MSK Physiotherapist (UK)
Diabetes is commonly associated with blood sugar control, but did you know it can also significantly impact your muscles, joints, tendons, and nerves? If you or someone you know is living with diabetes, understanding how it affects the musculoskeletal (MSK) system is vital. From frozen shoulder to nerve damage, this article explains the key links between diabetes and MSK conditions—and what you can do about it.
The information is also presented in video format below
What Is Diabetes?
Diabetes is a chronic condition in which the body either doesn’t produce enough insulin, or can’t use it effectively. Insulin is a hormone made by the pancreas that helps move glucose (sugar) from the bloodstream into cells to be used for energy. When this system fails, glucose builds up in the bloodstream and begins to damage various tissues in the body.
There are two main types of diabetes:
- Type 1 Diabetes: Usually diagnosed in children and young adults, this is an autoimmune condition where the body’s immune system attacks insulin-producing cells. Management involves insulin therapy.
- Type 2 Diabetes: Is where the body becomes resistant to the effects of insulin. Its a much more common condition than Type 1 and is often diagnosed in older adults. Type 2 diabetes is linked with genetics, obesity, and sedentary lifestyles. It can lead to a wide range of complications, particularly when poorly controlled. In 2022, it was estimated to cost the U.S. economy over $400 billion.
Pre-diabetes is where blood sugar levels are elevated but not yet high enough for a Type 2 diabetes diagnosis. Even at this stage, damage to the body can begin. Being pre-diabetic is a warning sign to start making the healthy changes to your lifestyle in order to prevent it from developing into the full blown condition.
How Is Diabetes Managed and Measured?
Controlling diabetes focuses on keeping blood sugar levels in a healthy range. Common strategies include:
- Dietary changes (reducing sugary and processed foods)
- Regular physical activity (to use up stored glucose)
- Weight management (reducing body weight can improve insulin sensitivity)
- Medications, such as metformin
- Insulin therapy (essential for type 1 and advanced type 2 cases)
Key tools used to monitor diabetes control:
- Fasting glucose tests
- Daily blood sugar monitoring / Wearable Glucose Monitor
- HbA1c test, which measure average glucose over 3 months
An HbA1c level of 48 mmol/mol or higher usually indicates diabetes.
For diabetics, keeping it below 53 should be the target.
An HbA1c consistently above 75 is strongly linked to many complications, including blood vessel damage (peripheral vascular disease), increased risk of stroke and heart attack, kidney failure, vision loss, and even amputation.
How Does Diabetes Affect the MSK System?
Prolonged high blood sugar levels can cause:
- Inflammation
- Damage to small blood vessels
- Disruption of collagen (a key structural protein)
- Delayed healing and recovery
- Impaired nerve function
Together, these factors contribute to a much higher risk of developing musculoskeletal problems and make recovery from injuries slower and more complicated.
Common MSK Conditions Linked to Diabetes
1. Frozen Shoulder (Adhesive Capsulitis)
- Painful stiffness and restricted movement
- Up to 5x more common in people with diabetes
- Caused by inflammation and collagen changes
2. Trigger Finger (Stenosing Tenosynovitis)
- Finger locks in a bent position and then releases
- Caused by tendon sheath thickening
- More likely in long-standing diabetes, often affects multiple fingers
3. Diabetic Neuropathy
- Damage to peripheral nerves, especially in the hands and feet
- Symptoms: numbness, tingling, burning, weakness
- Increases fall risk and may cause muscle wasting
4. Tendinopathy
- Painful, weakened tendons from overuse
- Diabetes alters tendon structure and healing
- Common in Achilles, rotator cuff, and patellar tendons
5. Dupuytren’s Contracture
- Thickened tissue in the palm pulls fingers inward
- Strongly associated with type 2 diabetes
6. Osteoarthritis and Charcot Joint
- Increased joint inflammation accelerates arthritis
- Charcot arthropathy leads to breakdown of foot joints in diabetics with neuropathy, resulting in pain, swelling and stiffness of the foot.
7. Delayed Healing and Post-Surgery Recovery
- Higher infection risk
- Poorer scarring and slower rehab after surgery or injury
What Can You Do About It?
Here’s the good news: many MSK complications can be improved or prevented through better blood sugar control. As a physiotherapist, I often tell patients that the first step to managing their pain is improving their diabetic control. Without that, many conventional treatments may not be effective.
Key steps you can take:
1) Follow medical advice and stick to your treatment plan.
2) Stay physically active with daily movement and exercise.
3) Maintain a healthy weight to reduce joint stress and improve insulin sensitivity.
4) Monitor your feet regularly for signs of damage or infection.
5) Don’t ignore pain that lasts more than a few weeks.
6) Seek physiotherapy advice early for joint or tendon issues.
By managing your diabetes effectively, you’re not just reducing long-term risks—you’re also protecting your ability to move, work, and enjoy life.
Final Thoughts
If you have diabetes, controlling your blood sugar isn’t just about preventing serious complications like heart disease or kidney failure. It’s also about safeguarding your joints, tendons, and nerves—and maintaining your mobility and independence.
For more evidence-based advice on musculoskeletal health, explore other articles and videos on this site. Stay informed, stay active, and take care of your body.