The shoulder joint is a ball and socket joint that connects the arm to the body. It is formed by the head of the humerus (ball) and the glenoid fossa on the shoulder blade (socket). Unlike the hip joint, the shoulder joint has a shallow socket. This enables the shoulder to have a large range of motion, however, because of this it can be prone to instability. To assist in the stability of the joint, the shoulder is reinforced by: deep ligaments that lie over the joint capsule, the labrum around the joint, and the rotator cuff. The rotator cuff forms broad, flat tendons that cover the ball. Its job is to keep the ball centered in the socket, stabilizing the shoulder joint.
Shoulder instability refers to when there is excessive motion between the ball and socket of the shoulder joint, leading to dislocations (where the ball moves out of the socket) or subluxations (where the ball moves to the edge of the socket but not out of it).
Traditionally we would classify this into two types: atraumatic and traumatic.
Traumatic dislocations occur due to an event or injury. They usually occur in younger, more active individuals. The non-operative management of these types of shoulder dislocations involves a period of protecting the injured tissues and then strengthening the rotator cuff and scapular muscles and improving the neuromuscular control of the shoulder joint. These injuries can lead to recurrent dislocations that sometimes require surgery. There is evidence that by strengthening, there is a reduced rate of future dislocations. If this is you, please begin the Physio Fixes program 2-3 weeks following your dislocation or as directed by your medical professional.
Atraumatic dislocations do not occur due to an injury. It is thought that in this group structural differences (collagen tissue laxity or structural abnormalities) or repetitive microtrauma lead to instability. Researchers have found that an exercise program is effective management for 80% of patients in this group. Exercise in this group has a large focus on movement control/neuromuscular exercises and strengthening of the rotator cuff, scapular and postural muscles.
Please see the Physio Fixes program for more information!
DISCLAIMER: This information is not intended as medical advice or a substitute for medical counseling. By choosing to follow the information that follows, you recognize that despite all precautions taken by Physio Fixes Inc. there is a potential risk of injury and you expressly acknowledge such risks and waive, relinquish, and release any claim that you may have against Physio Fixes Inc. You should always get evaluated for exercise by a physician or medical professionals, especially if symptoms occur from a trauma or are worsening. The user agrees by purchasing this program that Physio Fixes will not be held responsible in the event that an injury occurs.
References
Chiddarwar V, de Zoete RMJ, Dickson C, Lathlean T. Effectiveness of combined surgical and exercise-based interventions following primary traumatic anterior shoulder dislocation: a systematic review and meta-analysis. Br J Sports Med. 2023 Dec;57(23):1498-1508. doi: 10.1136/bjsports-2022-106422. Epub 2023 Jul 14. PMID: 37451706.
Coulthard C, Cairns MC, Williams D, Hughes B, Jaggi A. Management of atraumatic shoulder instability in physiotherapy (MASIP): a survey of physiotherapy practice. BMC Musculoskelet Disord. 2021 Sep 30;22(1):840. doi: 10.1186/s12891-021-04677-9. PMID: 34592969; PMCID: PMC8485495.
Hayes K, Callanan M, Walton J, Paxinos A, Murrell GA. Shoulder instability: management and rehabilitation. J Orthop Sports Phys Ther. 2002 Oct;32(10):497-509. doi: 10.2519/jospt.2002.32.10.497. PMID: 12403201.
Lowry V, Lavigne P, Zidarov D, Matifat E, Cormier AA, Desmeules F. A Systematic Review of Clinical Practice Guidelines on the Diagnosis and Management of Various Shoulder Disorders. Arch Phys Med Rehabil. 2024 Feb;105(2):411-426. doi: 10.1016/j.apmr.2023.09.022. Epub 2023 Oct 11. PMID: 37832814.
Mitchell C, Adebajo A, Hay E, Carr A. Shoulder pain: diagnosis and management in primary care. BMJ. 2005 Nov 12;331(7525):1124-8. doi: 10.1136/bmj.331.7525.1124. PMID: 16282408; PMCID: PMC1283277.
Reinold MM, Escamilla RF, Wilk KE. Current concepts in the scientific and clinical rationale behind exercises for glenohumeral and scapulothoracic musculature. J Orthop Sports Phys Ther. 2009 Feb;39(2):105-17. doi: 10.2519/jospt.2009.2835. PMID: 19194023.
Srinivasan S, Pandey R. Current Concepts in the Management of Shoulder Instability. Indian J Orthop. 2017 Sep-Oct;51(5):524-528. doi: 10.4103/ortho.IJOrtho_224_17. PMID: 28966375; PMCID: PMC5609373.
Varacallo M, Musto MA, Mair SD. Anterior Shoulder Instability. [Updated 2023 Aug 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538234/
Wilk KE, Macrina LC, Reinold MM. Non-operative rehabilitation for traumatic and atraumatic glenohumeral instability. N Am J Sports Phys Ther. 2006 Feb;1(1):16-31. PMID: 21522197; PMCID: PMC2953282.
