Let’s begin with a brief discussion of shoulder joint anatomy.
The shoulder is a complex and highly mobile joint, crucial for many activities. Its anatomy can be understood in terms of bones, muscles, ligaments, and tendons:
Bones: The shoulder is comprised of three main bones:
Scapula (Shoulder Blade): A large, triangular bone with a complex surface, providing attachment sites for muscles.
Clavicle (Collarbone): This bone connects the scapula to the sternum, helping to stabilize the shoulder.
Humerus (Upper Arm Bone): The ball at the top of this bone fits into the socket of the scapula to form the main shoulder joint.
Bones of the Shoulder Joint
2. Joints: There are several important joints in the shoulder:
Glenohumeral Joint: The main shoulder joint, where the head of the humerus fits into the glenoid cavity of the scapula.
Acromioclavicular Joint: Where the clavicle meets the acromion of the scapula.
Sternoclavicular Joint: The joint where the clavicle meets the sternum.
Scapulothoracic Joint: Where the Scapula contacts the thoracic spine.
Joints of the Shoulder
3. Muscles and Tendons: These provide movement and stability to the shoulder:
Rotator Cuff: A group of four muscles (Supraspinatus, Infraspinatus, Teres Minor, and Subscapularis) and their tendons that stabilize the glenohumeral joint and facilitate arm rotation.
Muscles of the Rotator Cuff
Deltoid: This large, triangular muscle covers the shoulder joint and aids in arm abduction.
Biceps and Triceps: Located in the upper arm, they also play a role in shoulder movement.
4. Ligaments and Bursae:
Ligaments: Bands of tough, elastic tissue that connect bones to each other, providing stability to the shoulder joint.
Bursae: Fluid-filled sacs that reduce friction and cushion the areas between bones, tendons, and muscles.
This intricate structure allows for a wide range of motion, including lifting, pushing, and pulling, but also makes the shoulder susceptible to injuries and disorders such as dislocation, impingement, or rotator cuff tears. Regular exercise and proper ergonomics can help maintain shoulder health and prevent injuries.
Shoulder pain can arise from various causes, including muscle strain, joint issues, or nerve compression. Trigger points, specifically, are a common source of muscle-related shoulder pain.
Trigger Points: These are tender, tight spots in a muscle, often described as "knots." They can cause localized pain or refer pain to other areas, a phenomenon known as referred pain. Trigger points in the shoulder muscles can cause pain that radiates to the neck, arm, or upper back.
Common Causes of Trigger Points in the Shoulder:
Overuse or Injury: Repetitive motions or injuries can lead to the development of trigger points in the shoulder muscles.
Poor Posture: Prolonged poor posture, like slouching or working at a desk, can strain shoulder muscles.
Stress: Stress can lead to muscle tension, contributing to the formation of trigger points.
Lack of Movement: A sedentary lifestyle can lead to stiff muscles, increasing the risk of trigger points.
Symptoms of Trigger Points:
Sharp, aching pain in the shoulder
Pain that radiates to other areas
Limited range of motion
Muscle knots felt under the skin
Treatment and Management:
Physical Therapy: Exercises and stretches can help alleviate pain and improve mobility.
Massage Therapy: Trigger point pressure release techniques to deactivate.
Heat Therapy: Applying heat can relax tight muscles and improve blood flow.
Dry Needling: This modality can target trigger points directly to relieve pain.
Rest and Activity Modification: Avoiding activities that exacerbate pain can help in recovery.
Prevention:
Regular exercise to maintain muscle strength and flexibility
Good posture, especially when sitting for long periods
Stress management techniques like meditation or yoga
In the coming weeks we will see how trigger points can lead to common shoulder problems such as tendinitis, bursitis, osteoarthritis, adhesive capsulitis, and rotator cuff degenerative changes and tears.
If you feel your shoulder pain may be related to trigger points and would like an evaluation by our licensed physical therapists, feel free to schedule your free consult.
