General Science

Shoulder Separation

A shoulder separation is the partial or complete separation of two parts of the shoulder: the collarbone (clavicle) and the end of the shoulder blade (acromion).

Shoulder

The collarbone and the shoulder blade (scapula) are connected by the acromioclavicular (AC) joint, which is held together primarily by the acromioclavicular (AC) and the coracoclavicular (CC) ligaments. In a shoulder separation (also called an acromioclavicular joint injury), these ligaments are partially or completely torn. A shoulder separation is classified according to how severely these ligaments are injured:

What is the Scapula?

The scapula (shoulder blade) forms part of the shoulder, at the back. It is a triangular, flattened bone, with several projections. The scapula is attached to the outer end of the collar bone (clavicle) at the acromioclavicular joint. Its outer end provides a socket for the head of the upper arm bone (humerus), forming the bony articulation of the shoulder joint. The Scapula is held in place by strong muscles, which can move it in relation to the chest wall. It provides attachment for many of the muscles of the shoulder and upper arm, including the biceps.

Shoulder Anatomy and Physiology

Detecting and Treating Shoulder Impingement Syndrome

The Role of Scapulothoracic Dyskinesis

Michael J. DePalma, MD; Ernest W. Johnson, MD

THE PHYSICIAN AND SPORTSMEDICINE - VOL 31 - NO. 7 - JULY 2003

In Brief: The shoulder joint is most appropriately referred to as the "shoulder complex," since its total range of motion depends on four interworking articulations. The scapula is central in proficient shoulder activity, and rotator cuff muscles will not operate optimally if the scapula is poorly positioned. Dynamic scapular stabilization requires coordinated muscular activity, and muscle dysfunction will lead to glenohumeral incongruity during overhead athletic activities. Lack of scapular protraction, upward rotation, and posterior tilting can lead to subacromial impingement. Pain inhibition and fatigue can also provoke altered muscle patterns, but rehabilitation exercises can address biomechanic deficiencies.

Thoracic position effect on shoulder range of motion, strength, and three-dimensional scapular kinematics.

Kebaetse M, McClure P, Pratt NA.

Department of Physical Therapy, Allegheny University of the Health Sciences, Philadelphia, PA, USA.

OBJECTIVES: To determine the effect of thoracic posture on scapular movement patterns, active range of motion (ROM) in scapular plane abduction, and isometric scapular plane abduction muscle force. STUDY DESIGN AND METHOD: Repeated measures design. There were 34 healthy subjects (mean age, 30.2 yrs). Each subject was positioned and stabilized while sitting in both erect and slouched trunk postures. In each sitting posture a three-dimensional electromechanical digitizer was used to measure thoracic flexion and scapular position and orientation in three planes. Measurements were taken with the arm (1) at the side, (2) abducted to horizontal in the scapular plane, and (3) at maximum scapular plane abduction. In each posture, isometric abduction muscle force was measured with the arm at the side and abducted to horizontal in the scapular plane. RESULTS: In the slouched posture, the scapula was significantly more elevated in the interval between 0 to 90 degrees abduction. In the interval between 90 degrees and maximum abduction, the slouched posture resulted in significantly less scapular posterior tilting. There was significantly less active shoulder abduction ROM in the slouched posture (mean difference = 23.6 degrees +/- 10.7 degrees). Muscle force was not different between slouched and erect postures with the arm at the side, but with the arm horizontal muscle force was decreased 16.2% in the slouched position. CONCLUSION: Thoracic spine position significantly affects scapular kinematics during scapular plane abduction, and the slouched posture is associated with decreased muscle force.

Fracture of the Thoracic and Lumbar Spine

Fracture of one or more parts of the spinal column (vertebrae) of the middle (thoracic) or lower (lumbar) back is a serious injury usually caused by high-energy trauma like a car crash, fall, sports accident or act of violence (i.e., gunshot wound). Males experience the injury four times more often than females do. The spinal cord may be injured depending on the severity of the fracture. Symptoms include:

* Moderate to severe back pain made worse by movement.

* In some cases when the spinal cord is also involved, numbness, tingling, weakness or bowel/bladder dysfunction.

When you fracture the thoracic and lumbar spine, surgery or bracing is often necessary. Often, patients also have other life-threatening injuries. People with osteoporosis, tumors or other underlying conditions that weaken bone can get a spinal fracture with minimal trauma or normal activities of daily living.

Glenohumeral Instability

What is Glenohumeral Instability?
After being treated for an initial dislocation of your shoulder, you may find that it feels like it's about to dislocate periodically. This feeling of giving-way is called glenohumeral instability or subluxation.

Glenohumeral instability refers to a condition in which the humeral head in the shoulder repeatedly slips out of the joint, or seems to nearly slip out.

The shoulder blade and humerus, or upper arm, form the glenohumeral joint. This is what you would normally think of as your 'shoulder joint'. The glenohumeral joint is a ball-and-socket joint, consisting of the head of the humerus, or upper arm, and the glenoid fossa, which is formed by a slightly hollowed portion of the end of the shoulder blade. The head of the humerus maintains very little contact with the glenoid itself during movement, however. Instead, the shoulder relies on a group of ligaments, muscles and tendons to help keep the humerus in the proper place, and to provide stability to the joint.

Spinal Cord Trauma

Vertebrae

Cauda Equina

Vertebra and Spinal Nerves

Alternative names
Spinal cord compression or injury; Compression of spinal cord

Definition Return to top

Spinal cord trauma is damage to the spinal cord that results from direct injury to the cord itself, or from indirect injury from damage to the bones, soft tissues, and blood vessels surrounding the spinal cord.

Causes, incidence, and risk factors Return to top

Spinal cord trauma can be caused by any number of injuries to the spine. They can result from motor vehicle accidents, falls, sports injuries (particularly diving into shallow water), industrial accidents, gunshot wounds, assault, and others.

Laminectomies and Fiber Optic Procedures

Q: He has explained that there is a compressed nerve in my spine. He wants to do surgery called a "laminectomy." Can you explain this procedure and how it will help my pain?
A:

There are many types of back surgeries and some of them will help pain. Because there are many causes of back pain related to the spine, there are also many different approaches doctors take to relieve the pain. Most back surgery is performed because there is a specific problem in the spine that results in what are called "neurological signs." These signs include objective symptoms such as numbness or weakness in the arms, back or legs. Major back surgery may help these neurological signs and the pain, but this type of surgery is usually performed more to stop the progression of neurological problems and is usually not performed solely to relieve pain. Sometimes, the specific neurological problem can be relieved from the surgery, but the pain is not relieved and persists after recovery from the surgery itself.

Core Stability

Although the world's top golfers rely on an indefinable combination of concentration, physical endurance, skill and consistency to remain at the top of their game, the application of strength and conditioning know-how in the area of core stability is beginning to make an impact in the sport...

The functional result of good core stability is that when an athlete is performing sporting movement or technique, they are able to maintain the correct posture and alignment, particularly in the lumber spine and pelvic area - key areas in any golf swing.

By maintaining correct posture and alignment, the athlete should have better technique. In a sport like diving, or gymnastics which is dependent to an extent on aesthetics, an athlete would look more controlled. In a running event, enhanced core stability would mean that an athlete would be able to apply force more efficiently, while also helping to reduce the risk of any injury