Abstract
Few manual techniques for reducing anterior shoulder dislocations are easy to perform in the clinical setting, and many of these techniques require sedation. The authors describe a technique, the Legg reduction maneuver, that is easy to perform on site and requires no premedication. Clinical experience indicates that proper use of this maneuver can successfully relocate a patient's anterior shoulder dislocation. The relocated arm can then be placed in an immobilizer and receive further medical management as appropriate. The Legg reduction maneuver allows the physician to work with the natural tendencies of muscle groups in the patient, rather than against them. Thus, the technique can be performed without sedation. In addition, because no traction is placed on the injured shoulder, the potential for neurovascular injury is decreased.
The shoulder has the greatest range of motion of any joint in the human body. As such, it is one of the most commonly injured joints. Anterior shoulder dislocation is an injury that is frequently encountered by physicians treating patients who have had acute trauma, such as injuries from contact sports, occupational hazards, and motor vehicle crashes.
Various techniques have been described in the literature for reducing anterior shoulder dislocations.
1 However, few of these techniques are easy to perform in the clinical setting, and many require patient sedation. The “Legg” reduction maneuver technique described in the present report, by contrast, is easy to perform on site and requires no premedication of patients.
A patient who has an anterior shoulder dislocation typically presents to the family physician with an obvious deformity.
2 Physical examination of the patient reveals a prominent acromion process and an anteriorly displaced humeral head, resulting in a loss of the natural contour of the shoulder. There will also often be marked swelling of the shoulder, and the patient will usually complain of pain, especially associated with motion. Classically, the patient will support the injured arm with the unaffected limb, keeping the arm in external rotation and slight abduction.
The physician should conduct a neurovascular examination before and after any reduction of an anterior shoulder dislocation.
3 If the reduction is successful, the patient should experience immediate relief of pain, and the natural contour of the shoulder should be restored. If the patient is able to place the hand of the affected limb on the opposite shoulder comfortably, it is quite likely that the reduction maneuver was effective.
3
The reduction maneuver described in the present report is named for William J. Legg, DO. Dr Legg developed this technique in the mid-1980s and used it successfully to treat athletes on sports field sidelines and patients in the emergency department throughout his lengthy career as an osteopathic physician in family practice.
Dr Legg is currently retired from active practice but continues to instruct medical students at the Kansas City University of Medicine and Biosciences in Mo.
Two practitioners are required to apply the Legg technique with a patient—one osteopathic physician to perform the reduction and one assistant to stabilize the unaffected shoulder. The application of the technique involves the following steps:
After the Legg technique is performed properly, the patient's dislocated shoulder should relocate. If the procedure is unsuccessful, it can be attempted again, making sure that the unaffected shoulder is firmly stabilized. The relocated arm can then be placed in an immobilizer and additional medical management can be provided as appropriate.
The Legg reduction maneuver is effective because it involves motions specifically designed to neutralize the various muscle groups that tend to resist shoulder relocation. By abducting the arm, tension on the supraspinatus and deltoid muscles is relaxed. External rotation reduces tension on the chief external rotators of the rotator cuff—the infraspinatus and teres minor. Flexion of the elbow acts to reduce tension on the coracobrachialis and bicep muscles.
The actual reduction occurs with adduction and internal rotation of the arm, using the subscapularis and latissimus dorsi muscles to assist in the relocation.
In performing the Legg reduction maneuver, the physician works with the natural tendencies of muscle groups in the patient, as opposed to working against them. This is the aspect of the technique that allows it to be performed without patient sedation. In addition, the technique requires no traction to be placed on the injured shoulder, decreasing the potential for neurovascular injury. The Legg reduction maneuver is a clinically useful technique for treating patients who have anterior shoulder dislocation.