Gleno-Humeral Joint (GHJ)
Introduction
Within the shoulder complex, there are 3 joints, which synergistically work together to allow for movement, which is needed for sporting and generic needs. The joint in the shoulder were exploring today is the Gleno-humeral joint. The Glenohumeral joint is a ball and socket joint, which allows for a large range of motion. In general, we use this joint every day but underestimate its complexity and ability to produce the movement in which we need.
image from www.eorthopod.com
The Anatomy of the Glenohumeral Joint.
The topographies of the Glenohumeral joint (GHJ) are: a humeral head, a fibro cartiliginous glenoid labrum (GL), glenoid cavity, ligaments and bursas. Overall, the fibro cartiliginous presence overlaying the glenoid rim adds joint stability to the GHJ due to an increase in the concavity-compression mechanism caused by the GL; therefore, causing a decrease in humeral head translation. Amongst 10% of the patient population, there have been three reported anatomical differentiations within the GHJ. Firstly, there are reports of a cord like middle Glenohumeral ligament with a non-existent presence of anterior-superior labral tissue; this is commonly known as the Buford complex. Incidences of the Buford complex is said to be 2.5% within the military population. Secondly, variations are sometimes seen with the size of the sub-labral recesses sizes. On the whole, the Gleno-humeral joint is a complex joint which has a variety of rare anatomical differences between different people of the population. Therefore, treatments and rehabilitation strategies are always changing.
The Main Movements of the Glenohumeral Joint.
Flexion
Extension
Medial Rotation
Lateral Rotation
Abduction
Adduction
Horizontal Flexion
Horizontal Abduction
Possible Injuries to the Joint.
The shoulder is an extremely mobile joint, which allows for a large range of motion. However, with a large range of motion comes the increase in likely hood of ascertaining an injury. Common injuries to the shoulder occur in individuals who carry out daily overhead exercises on a regular basis (labourer). Moreover, in a sporting context damage to the shoulder joint commonly occurs from traumatic injuries to the area. In general, there are several types of injury, which can occur at this specific joint:
Bankart Lesion https://www.youtube.com/watch?v=-sdw465tiL4
SLAP Lesion
Bicep Tendinopathy
Rotator Cuff Tendinopathy
Multidirectional instability (caused by either or both ligament laxity and rotator cuff hypoplasia)
Bursitis of one of the four bursae’s known within the typical population.
The above list is only a few injuries, which may happen to the Gleno-humeral joint.
On the whole, the shoulder joint is a compact joint; however, it is highly susceptible to injuries due to the mobility of the joint itself.
More blogs on the shoulder to come in the future.
References
Abrams, G.D. & Safran, M.R. (2010) Diagnosis and Management of Superior Labrum Anterior Posterior Lesions in Overhead Athletes. British Journal of Sports Medicine. Vol. 44: 311–318.
Arai, R., Kobayashi, M., Toda, Y., Nakamura, S., Miura, T. & Nakamura, T. (2012) Fiber components of the shoulder superior labrum. Surgical and Radiologic Anatomy. Vol. 34, No. 1: 49–56.
Kanatli, U., Ozturk, B.Y. & Bolukbasi, S. (2010) Anatomical variations of the anterosuperior labrum: Prevalence and association with type II superior labrum anterior-posterior (SLAP) lesions. Journal of Shoulder and Elbow Surgery. Vol. 19, No. 8: 1199–1203.
Ben Kibler, W., Sciascia, A.D., Hester, P., Dome, D. & Jacobs, C. (2009) Clinical utility of traditional and new tests in the diagnosis of biceps tendon injuries and superior labrum anterior and posterior lesions in the shoulder. The American Journal of Sports Medicine. Vol. 37, No. 9: 1840–1847 .
Knesek, M., Skendzel, J.G., Dines, J.S., Altchek, D.W., Allen, A. a & Bedi, A. (2013) Diagnosis and management of superior labral anterior posterior tears in throwing athletes. The American Journal of Sports Medicine. Vol. 41: 444–60. [Online] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23172004.