Note: Deltoid & RC

Depending on particular task certain muscles required for stabilization and others as mobilizers for shoulder girdle balance For movement optimization as well as joint centralization , a perfect balance of mobilizer and stabilizer required.Upper cross syndrome is good example of muscles imbalance. In Upper cross syndrome, shoulder are protracted  and a head-forward carriage which lead to scapular winging and decentralization of the glenohumeral joint.

However, many literature have not co relate changes of posture can lead to rotator cuff tendinopathy. In my clinical practice, i feel that it plays a major role in many rotator cuff tendinopathies—particularly in those who perform overhead activities. In slump posture there is always a limited ROM of shoulder as compare to military posture. In slump posture, You should have 50% less range of motion of shoulder girdle. You most will feel strain in the rotator cuff at about 90 degrees. We are talking about loss of function not a pain.

Deltoid Shear force

The main function of rotator cuff is to maintain the head of humerus in centralization position within glenoid fossa. In rounded shoulder postures, alteration of mechanical axes of the glenoid fossa. It causes the brain to activate those muscles which are at rest, such as upper traps, levator scapula, pec minor and the deltoids.

These muscles are global mobilizer. The global mobilizer muscles convert into stabilizer due to faulty movement pattern.Once these dysfunction sets in joint which creates the pathology. Overdevlopment of posture whihc eventually undermines rotator cuff stability, causing a ‘deltoid shear’ that can elevate and compress the humeral head into the top part of the glenoid fossa . In this position, arm abduction to 90° is more likely to impinging the supraspinatus tendon against the acromion. It cause micro-fraying, fibrosis, and possible tendinosis.

Poor posture may start as muscles imbalance.Eventually,  it manifests as a sign of functional weakness in the hardware. Passively stretching of tight capsule may resolve only the stiff shoulder problem. Active movement to the restrictive tissues reinforces available ROM. This has been done along with mobilization.Start active movement of particular joint helps the patients  psychologically reinforce that he can move the arm through a greater range of motion.

Physiologically, active movement not only assists in healing collagen tissue allowing it to align itself along normal stress lines.Hence,it also helps in restoration of normal strength. Active movement also nourishes articular cartilage and enhances repair of damaged tissues.Once proper glenohumeral mobility is restored, home exercise program advice which includes exercises for core stability, scapular stabilization, and rotator cuff strengthening.