The infraspinatus muscle is one of the muscles that makes up the rotator cuff. It originates on the infraspinous fossa of the scapula, and inserts on the middle facet of the greater tubercle of the humerus. It functions to externally rotate the humerus and to stabilize the head of the humerus in the glenoid cavity during upward movement of the arm. Trigger points in this muscle refer pain deep into the anterior shoulder joint and down the anterior arm. Trigger points near the lower medial border refer pain into the rhomboids. This muscle is often injured during throwing motions.
Trigger Point Therapy
Trigger points in the triceps muscle.
The tricep muscle is named for its three heads long, medial, and lateral. The long head originates on the infraglenoid tubercle, the medial head on the posterior humerus, and the lateral head on the posterior humerus as well. They join together to insert on the Olecranon process of the ulna. The triceps function to extend the elbow. Strong extension under resistance can cause trigger points to form. Pain referred from triceps trigger points can be felt in the posterior shoulder and down the posterior forearm, as well as in in the olecranon process and the lateral epicondyle which can cause “tennis elbow” pain.
Pathophysiology of trigger points.
A large number of factors have been identified as causes of trigger point activation. These include acute or chronic overload of muscle tissue, disease, psychological distress, systemic inflammation, homeostatic imbalances, direct trauma, radiculopathy, infections, and lifestyle choices such as smoking. Trigger points form as a local contraction of muscle fibres in a muscle or bundle of muscle fibres. These can pull on ligaments and tendons associated with the muscle which can cause pain to be felt deep inside a joint. It is theorized that trigger points form from excessive release of acetylcholine causing sustained depolarization of muscle fibres. Trigger points present an abnormal biochemical composition with elevated levels of acetylcholine, noradrenaline and serotonin and a lower ph. The contracted fibres in a trigger point constricts blood supply to the area creating an energy crisis in the tissue that results in the production of sensitizing substances that interact with pain receptors producing pain. When trigger points are present in a muscle there is often pain and weakness in the associated structures. These pain patterns follow specific nerve pathways that have been well mapped to allow for accurate diagnosis or the causative pain factor.
Upper Crossed Syndrome/Desk Neck
Your posture plays an important role in your overall health. Poor posture leads to chronic strain and discomfort. “Upper crossed syndrome” describes poor posture that results from excessive tightness in your shoulders and chest with weakness in your neck and mid-back. This combination forces your shoulders to roll inward and your head to project forward.
To help understand how upper crossed syndrome causes trouble, think of your spine as a telephone pole and your head as a bowling ball that sits on top. When the bowling ball is positioned directly over the top of the upright post, very little effort is required to keep it in place. If you tip the post forward and the ball begins to roll over the edge of the post, significantly more effort would be required from the muscles trying to hold it there. This effort results in chronic strain of the muscles of your neck and upper back.
The chronic strain is uncomfortable and may also lead to neck pain, upper back pain, headaches, TMJ pain, and ultimately- arthritis. This postural problem is exceptionally common in computer workstation users.
Correction of this problem is accomplished by stretching the tight muscles, strengthening weak muscles, and modifying your workstation. Treatment is aimed at reducing and eliminating symptoms through the use of Chiropractic adjustments, soft tissue release, acupuncture and trigger point therapy.
Diagnosis of trigger points.
Diagnosis of trigger points typically takes into account symptoms, pain patterns, and manual palpation. When palpating the therapist will feel for a taut band of muscle with a hard nodule within it. Often a local twitch response will be elicited by running a finger perpendicular to the muscle fibres direction. Pressure applied to the trigger point will often reproduce the pain complaint of the patient and the referral pattern of the trigger point. Often there is a heat differential in the local area of the trigger point. 
Trigger points in the biceps Brachii muscle.
The Bicep Brachii is perhaps the most recognizable muscle in the body. It’s the muscle that is most often flexed when someone says ” show me your muscles”. It is composed of two heads, the long head and the short head. The short head originates on the coracoid process of the scapula, and the long head on the supraglenoid tubercle. Both heads merge to insert on the radial tuberosity and bicipital aponeurosis into the deep fascia on the medial part of the forearm. The main actions of this muscle are elbow flexion and forearm supination(rotation with the palm of the hand going upward). This muscle also assists shoulder flexion. Trigger points in this muscle mainly refer pain into the shoulder, with spillover into the posterior aspect above the scapula. A less common referral is into the anterior elbow and forearm. 
What is a trigger point
Dr Janet travel coined the term trigger point in 1942 to describe clinical findings with characteristics of pain related a discrete irritable point in muscle or fascia that was not caused by acute trauma, inflammation, degeneration, neoplasm or infection. The painful point can be palpated as a nodule or tight band in the muscle that can produce a local twitch response when stimulated. Palpation of the trigger point reproduces the pain and symptoms of the patient and the pain radiates in a predictable referral pattern specific to the muscle harbouring the trigger point.
Biceps Tendon Injury. The “suns out, guns out” injury.
Your biceps muscle attaches to your shoulder through two strong fibrous bands called “tendons.” The term “biceps tendinitis” means that one of these bands has become painfully irritated from strain or degeneration. Sometimes the tendon may be strained by an accident or lifting injury. Biceps tendinitis more often results from repeated pinching of the tendon beneath the bony part of your shoulder
from a condition called “impingement.” Repeated overhead activity, like throwing, swimming, gymnastics, and racquet sports are known culprits. Biceps tendinitis is often accompanied by other conditions, like rotator cuff tears or injuries to the cartilage around the rim of your shoulder joint. Factors that make you more likely to develop biceps tendinitis include: improper lifting techniques, inflexibility, poor posture, or repetitive overloading.
Your symptoms likely include a deep, throbbing ache over the front of your shoulder. The pain often refers toward the outside of your arm. The main job of your biceps muscle is to flex your elbow and turn your palm up, so overhead movements or activities that require flexion of your elbow may cause pain. Patients often report increased discomfort when initiating activity. Night time symptoms are common, especially if you lie on your affected shoulder. Be sure to tell your doctor if you notice popping, catching, or locking during movements, as this may suggest an additional problem. A painful, loud “pop” followed by relief with a visible bulge in your biceps (Popeye deformity) suggests that your tendon has ruptured.
Surgery is rarely required for biceps tendon problems unless you are a young athlete or worker who performs exceptionally heavy physical activity and have completely ruptured your tendon. The most effective treatment for the majority of biceps tendinitis patients is conservative care, like the type provided in our office. Initially, you may need to avoid heavy or repetitive activity, (especially overhead activity and elbow flexion) as returning to activity too soon may prolog your recovery. You should specifically avoid military presses, upright rows, and wide grip bench presses until cleared by your doctor. You may use ice over your shoulder for 10-15 minutes at a time each hour. The exercises described below will be a very important part of your recovery and should be performed consistently.
What to expect with a trigger point massage.
A treatment with Bryan is very user friendly. And, no, you don’t have to remove any clothing. However, bringing a t-shirt and a pair of shorts or sweats is recommended.
The first time you come for a treatment you will be asked to fill out a Client History form. Bryan will go over the information you provide, asking for more detail and discussing the type of pain you are having and its location.
The treatment itself involves locating the Trigger Points in the muscle or soft tissue and applying a deep focused pressure to the Point. This will reproduce the pain and the referral pattern that is characteristic of that pain.
The treatment will be uncomfortable at first, but as the Trigger Points release, the pain will decrease. The pressure will always be adjusted to your tolerance level. If, at any time, you feel too uncomfortable you can ask Bryan to ease off a bit.
Depending on your specific problem, Bryan may also use some stretching and / or range-of-motion techniques, as needed.
After treatment, it is usually recommended that the client apply moist heat to the area treated.
Trigger points in the deltoid muscle.
The deltoid is the the muscle that is most often thought of as the “shoulder.” It is the diamond shaped muscle that caps the shoulder joint. It originates on the clavicle, the acromion, and the spine of the scapula. It inserts on the deltoid tuberosity of the humerus. As a whole unit the deltoid laterally abducts the humerus at the glenohumeral joint. The anterior portion of the delt forward flexes the arm, as well as horizontally flexing the arm across the chest. Since the deltoid is involved in almost all shoulder movements it is especially prone to trigger points. Points in the anterior deltoid refer into the anterior and lateral shoulder. Trigger points in the posterior deltoid refer pain into the posterior shoulder with spillover down the lateral arm. 
Aberdeen Chiropractic 