The Human Disharmony Loop (HDL) is a novel syndrome of chronic pain of the upper limb described by:
What is the Human Disharmony Loop?
Dr. Ketan Sharma, MD, MPH
Hand & Nerve Injuries Specialist
Dr. James Friedman, MD
Shoulder & Sports Injuries Specialist
Who does the HDL affect?
All humans are prone to this, but patients tend to be:
- Bodybuilders / manual laborers
- Office and desk workers
- Female athletes
- Women with macromastia (large breast size)
- Overhead athletes (baseball, volleyball, basketball, tennis, etc)
- Worker’s Compensation
- Cervical spine disease or nerve block injuries
- History of trauma or surgery
Why does it happen?
The pectoralis minor (PM) is a small yet powerful muscle on the front of the chest attaching to the shoulder blade.
When the PM is tight, it pulls the scapula in a “down and in” direction, hunching the shoulder.
The scapula connects the body (thorax) to the arm (humerus) and coordinates all upper limb function.
Since the scapula is disturbed, the entire anatomy gets deranged, and patients develop widespread chronic symptoms of the neck, upper back, shoulder, arm, down to the hand.
How is the Human Disharmony Loop (HDL) Diagnosed?
- From history and physical exam by Dr. Sharma
- Prior testing, including X-rays, MRIs, and EMG studies is usually normal or shows something small (labral tears, carpal tunnel etc) that cannot explain the severity and widespread symptoms.
- A medial coracoid injection at the PM insertion relieves symptoms about 90% of the time, but does not rule out the syndrome.
How are these patients normally treated?
Patients have been tagged with various chronic pain syndromes, along with CRPS and fibromyalgia, and have usually seen many specialists and gone through many prior treatments including:
- Neck fusion
- Shoulder surgery (subacromial decompression, rotator cuff repair, arthroplasty)
- 1st rib resections / scalenectomy
- Botox injections
- Cubital and carpal tunnel releases
- Acupuncture
- Physical and occupational therapy
- Massage
What is the surgery to treat this?
- Through a small 2–3 cm incision, the PM is released from its insertion onto the scapula (tenotomy)
- Scar tissue underneath is released to free up the nerves (neurolysis)
- If insurance approves, an Amnion-based matrix is applied. The matrix dissolves by 6 weeks and accelerates healing, but the final recovery at 1 year is the same (nerve wrap)
What are the risks of the procedure?
- <4% risk of bleeding, infection, anesthesia, or wound healing issues
- The surgery does not involve or affect breast tissue at all
- No long-term impact to shoulder or arm function
What is the recovery?
- No lifting >5 lbs with the affected arm for 4 weeks
- Therapy after surgery is critical
*No surgery is 100% effective, and improvement can never be guaranteed
What are the outcomes of the procedure?
25% of patients require subsequent nerve decompressions (radial tunnel, cubital tunnel, carpal tunnel, etc.)
