Impact of Reverse Shoulder Arthroplasty Design and Patient Shoulder Size on Moment Arms and Muscle Fiber Lengths in Shoulder Abductors
Reverse shoulder arthroplasty (RSA) increases the moment arm of the deltoid, however there is limited knowledge on the accompanying changes in muscle architecture that play a role in muscle force production. The purpose of our study is to use a geometric shoulder model to evaluate the anterior deltoid, middle deltoid, and supraspinatus regarding 1) differences in moment arms and muscle-tendon lengths in small, medium, and large native shoulders, and 2) impact of three RSA designs on moment arms, muscle fiber lengths, and force-length (F-L) curves.
The neck and shoulders are complex and interconnected areas, and medical problems that affect one often affect the other, as well. Pain and dysfunction from injuries or conditions that impact the joints, muscles, and other structures can easily spread from the neck to the shoulder(s) and from the shoulder(s) to the neck.
Shoulder blade pain is a sign of lung cancer in some people. Lung cancer may be especially be suspected if you also have other symptoms of lung cancer or your shoulder pain worsens at night. With that said, shoulder pain is not a definite sign of lung cancer. Other diseases such as arthritis can cause pain in that area, too.
Your shoulder is a ball and socket joint and very mobile. It may hurt for many reasons, from injury and overuse to chronic conditions or diseases. You need to know the cause to get effective treatment.
Collarbone pain is usually caused by an injury, such as a fracture or joint separation. However, your collarbone (clavicle) can also hurt because of health conditions like arthritis or even certain sleeping positions.
While dead hangs may be OK for people with good upper-body strength and no shoulder problems, they can be risky for others. People with shoulder hypermobility (excessive motion of the shoulder) or shoulder instability (such as those who easily dislocate their shoulder) may need to be cautious. The shoulder, by design, is a relatively unstable joint. It has a large ball-type bone called a humerus, which sits in a relatively small socket called a glenoid.
A scapula fracture is an uncommon injury. The scapula, or shoulder blade, is a wide, flat bone that sits behind the rib cage. The scapula connects to the clavicle (collar bone) in the front of the body, and to the humerus (arm bone) at the side. Part of the scapula is lined with cartilage (the glenoid) and forms the socket of the ball-and-socket shoulder joint.
Repetitive Pitching Decreases the Elbow Valgus Stability Provided by the Flexor-Pronator Mass: The Effects of Repetitive Pitching on Elbow Valgus Stability
Baseball pitching induces a large elbow valgus load, stressing the ulnar collateral ligament. Flexor-pronator mass contraction contributes to valgus stability; however, repetitive baseball pitching may weaken the flexor-pronator mass contractile function. The present study investigated the effects of repetitive baseball pitching on the medial valgus stability measured using ultrasonography.
Isolated Primary Latarjet Procedures for Anterior Shoulder Instability Results in High Rates of Graft Resorption and Glenohumeral Degenerative Changes with Low Rates of Failure at a Minimum 2-Year Follow-Up: A Systematic Review
To evaluate the incidence of postoperative complications after an isolated primary Latarjet procedure for anterior shoulder instability at a minimum 2-year follow-up.
Arm pain can be in the upper or lower arm. You may feel arm pain on the outside of your shoulder. Arm pain can also travel further down the arm toward the elbow.