The supraspinatus muscle is the most active of the four rotator cuff muscles. It is responsible for abduction of the your arm at the shoulder. Most importantly, in conjunction with the other rotator cuff muscles, it is responsible for dynamic stabilization of the shoulder joint.
The shoulder has less connective tissue structure than other major joints. The rotator cuff muscles act as a sort of dynamic muscle/ligament hybrid to stabilize the shoulder joint as you move.
Of the important functions of supraspinatus is to provide resistance against the downward migration of your humerus during the arm swing of normal gait.
Trigger points in your supraspinatus cause pain on the side of the shoulder, and sometimes extending down the side of your arm to the elbow and forearm.
Supraspinatus trigger points are often involved with shoulder impingement syndromes. It is also the most frequently torn rotator cuff muscle.
Structure
The supraspinatus muscle arises from the supraspinous fossa, a shallow depression in the body of the scapula above its spine and the supraspinous fascia. It is thinner towards the spine and becomes thicker towards the shoulder. The fibers of the front side of supraspinatus are angled obliquely but the fibers on the back side of the muscle are more straight. This facilitates the multiple actions of supraspinatus. These two sections converge to form a thick tendon under the acromion of the shoulder blade. This narrow passage is one of the trouble spots for supraspinatus.Relations
As the tendon continues, it passes over the head of the humerus and inserts onto the greater tubercle. The tendon is thicker at the front side of its attachment and is interweaves with the tendons of subscapularis, infraspinatus and the pectoral fascia to form the transverse and coracohumeral ligaments. The tendon is flatter at its upper attachment and the deeper portion blends with the joint capsule. Recent research shows that the origin from the rear is more lateral than classically described. The supraspinatus muscle has three distinct heads that weave together to form the supraspinatus tendon. The head on the front side passes to the back, the head in the middle passes straight across and the head in the back passes to the front side. The thinner rear rear tendon overlaps the front and middle heads. This intertwines all three heads and increases the tensile capacity of the tendon. In about 50% of the population an overgrowth of connective tissue called an aponeurotic expansion continues from the beneath the supraspinatus tendon parallel to the long head of the biceps tendon in the biciptal groove. This is outside the tendon sheath and inserts into the humerus at the top of the pectoralis major tendon. Passing towards the shoulder joint from the infraspinatus muscle, deeper vertical fibers merge with the top of the supraspinatus tendon and cross the rotator cuff interval. These extend all the way to the biceps brachii muscle itself. This thick, fibrous tendon is called the rotator cable. It links the rotator cuff muscles in the back with the muscles on the front. The rotator crescent is the terminal connection of the supraspinatus and infraspinatus tendons that inserts onto the humerus next to the rotator cable. The rotator cable protects the rotator crescent by intrinsically transferring forces from the rear side of the rotator cuff to the front. This complicated arrangement allows the rotator cuff to work in a coordinated way no matter how your shoulder moves.Isotonic Contractions
Isotonic contractions maintain constant tension in the muscle as the muscle changes length. This can occur only when a muscle’s maximal force of contraction exceeds the total load on the muscle. Isotonic muscle contractions can be either concentric (muscle shortens) or eccentric (muscle lengthens).Concentric Contractions
A concentric contraction is a type of muscle contraction in which the muscle shortens while generating force. This is typical of muscles that contract due to the sliding filament mechanism, and it occurs throughout the muscle. Such contractions also alter the angle of the joints to which the muscles are attached. This occurs throughout the length of the muscle, generating force; causing the muscle to shorten and the angle of the joint to change. For instance, a concentric contraction of the biceps would cause the arm to bend at the elbow as the hand moves close to the shoulder (a biceps curl). A concentric contraction of the triceps would change the angle of the joint in the opposite direction, straightening the arm and moving the hand away from the shoulder.Eccentric Contractions
An eccentric contraction results in the lengthening of a muscle. These contractions decelerate muscles and joints (acting as “brakes” to concentric contractions) and can alter the position of the load force. During an eccentric contraction, the muscle lengthens while under tension due to an opposing force that is greater than the force generated by the muscle. However, rather than working to pull a joint in the direction of the muscle contraction, the muscle acts to decelerate the joint at the end of a movement or otherwise control the repositioning of a load. This can occur involuntarily (when attempting to move a weight too heavy for the muscle to lift) or voluntarily (when the muscle is “smoothing out” a movement). Strength training involving both eccentric and concentric contractions appears to increase muscular strength and joint stability more than training with concentric contractions alone.Isometric Contractions
In contrast to isotonic contractions, isometric contractions generate force without changing the length of the muscle. This is typical of muscles found in the hands and forearm: the muscles do not change length, and joints are not moved, so force for grip is sufficient. An example is when the muscles of the hand and forearm grip an object; the joints of the hand do not move, but muscles generate sufficient force to prevent the object from being dropped. For people with hypermobile joints, strength training can be a challenge. Tension stresses the connective tissues of the joint as force is transmitted through its range of motion. Isometric exercises can be ideal in these circumstances because there is minimal movement. This means that the joint is placed into vulnerable hyperextended positions under force. You can develop amazing strength without free weights, machines, or resistance bands. One of the original bodybuilder gurus from the 1920s, Charles Atlas, based his workouts primarily on isometric exercises, eventually even trademarking a term for his exercise method that he called "Dynamic Tension." If you have hypermobile joints you can strength train safely at home with isometric exercises.Professional Treatment With Us
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Clearly, everyone is different. Many of us have additional challenges and complications. Naturally, we tailor our treatment plans to the individual. However, there are common foundations in this work with everyone.
We are licensed professionals. In addition, we all have additional training and certifications in advanced techniques. For instance, this includes trigger point therapy, fascial stretching, neuromuscular and movement therapy. Also we offer kinesio taping, myofascial release, cupping, acoustic compression, self-care classes and more. In fact, we often combine several of these techniques into a single session..
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