The shoulder has the most mobility of any joint, and unfortunately the more mobility a joint has the less inherent stability there is. Because the joint has less stability it is often a joint that gets injured in martial arts, whether from traumatic fall, joint lock or overuse.
The shoulder complex is made up of several joints:
1. Glenohumeral joint: The glenohumeral joint involves the head of the humerus (upper arm) articulating with the glenoid fossa. The shoulder is classically what is considered the glenohumeral joint.
2. Sternoclavicular joint: The sternoclavicular joint or “SC joint” is where the proximal clavicle articulates with the sternum.
3. Acromioclavicular joint: The acromioclavicular joint or “AC joint” is where the distal clavicle articulates with the acromion. The SC joint and AC joint function together to elevation of the clavicle to assist with overhead motion.
4. Scapulothoracic “joint”: This is the scapula sitting onto of the thoracic spine. The scapulothoracic joint has to rotate upwardly to allow for overhead motion.
All four are involved in overhead arm motion. Additionally the thoracic spine and cervical spine may also influence shoulder motion.
1. Labrum: The glenoid fossa is a fairly small area, so the humeral head does not have a secure connection, however the glenoid labrum is a structure that deepens the glenohumeral joint and helps to reinforce the joint.
2. Joint Capsule: The joint capsule is connective tissue that surrounds the joint. The axillary pouch is a structures that helps to additionally reinforce joint.
3. Ligaments: There are several ligaments that help to add static stabilization: glenohumeral joint ligaments are classified by location: superior, middle and inferior. Each ligament stabilizes the shoulder in different ranges of motion.
4. Rotator cuff: The rotator cuff is a collection of 4 muscles whose primary job is to help stabilize the humeral head in the glenoid fossa while humeral elevation occurs.
The four muscles that collectively are referred to as “the rotator cuff”:
D. Teres minor.
Regarding medical advice it is always best to see a medical professional (PT, MD, DC, ATC etc…) in person. Proper assessment is the key to successful rehabilitation.
Common Shoulder complaints:
1. Shoulder is locking or catching:
Potentially a labrum tear. If the catching persists this may require surgery, especially if it is trauma induced.
2. Shoulder feels loose and unstable:
Potential a labrum tear or general ligament laxity. With a history of dislocation often people will present with persistent instability or looseness. A note concerning laxity, it does not equal instability. With appropriate muscular stability someone with general laxity may be asymptomatic. Persistent looseness often will respond to rehab.
Shoulder dislocations: When the stabilizers fail and the humeral head translates too far from the fossa. The most common dislocation is anterior (forward). The static stabilizers often gets damaged or torn so repeated dislocations are common after the first.
Why does the labrum get damaged in fighting?
Biceps brachii is an arm muscle with two heads, and the long head of the biceps has significant attachment to the superior aspect of the labrum (up to 50%). Due to the strong connection with the labrum when there are large or repetitive forces on or from the biceps load will be transferred to the labrum. This occurs in combat sports with repetitive maximal punches.
An example of this in boxing was Lomachenko vs Linares. When Lomachenko throws the lead hook it appears that his shoulder translates too far forward (anterior dislocation) and he relocates it with the excessive swing back. Following the fight it was revealed Lomachenko did have a severe labrum tear and significant instability. Some labrum tears may respond to conservative treatment but in his case surgery was required.
An example of this in jiu jitsu was Leandro Lo against Mahamed Aly. Lo attempted a takedown and in the transition he had a faulty landing which resulted in an inferior shoulder dislocation. Lo was able to continue however during a sweep attempt his shoulder dislocated again and he had to concede the match.
3. Shoulder is stiff and tight:
Shoulder movement is influenced by many joints: shoulder itself (glenohumeral joint), acromioclavicular joint, sternoclavicular joint, scapulothoracic joint, cervical and thoracic spine. In short many structures may be limiting your shoulder mobility.
Shoulder mobility exercises:
Controlled articular rotations: Active movement drills designed for improvement of shoulder mobility. The intention of these exercises are to isolate motion to the specific joint being moved. The motion should be PAIN-FREE. Do not move through a painful range of motion. When there is pain with movement I would advise to get your shoulder properly assessed by a healthcare professional.
4. Shoulder is painful with movement:
Often pain with active muscle activation and resistance is related to muscle and may be a muscle strain, tendinitis or rotator cuff tear. The primer movers for the shoulder generally are deltoids while the rotator cuff muscles act as stabilizers. Due to the proximity of the biceps brachii insertion on the labrum often this muscle may also be irritated.
5. Painful bony protrusion near the end of the collar bone:
Often this is an acromioclavicular sprain. This injury tends to occur from a traumatic fall: overhead throw or sweep. Most cases respond to conservative care but severe cases may require surgery. For a more detailed explanation for AC sprains please review my post: http://doctorkickass.com/grappling-injuries/shoulder-injury-from-falling-ac-sprains-and-grappling/
This video is a clip from a grappling match between Gilbert Burns vs Gregor Gracie. As Burns slams Gracie, he lands improperly on his shoulder and isn’t able to continue. Gracie confirmed that he suffered a Type II AC sprain from the fall.
6. Shoulder/arm is burning, tingling or shocking:
This may be due to a nerve entrapment or neck pain referring to the arm.
Because of the complicated nature of the shoulder and the variety of pathology that can occur the best course of action is to get properly assessed so you can start to rehab properly and efficiently.