Does the shoulder joint undergo greater stress from different types of martial arts and fighting styles than others and if so which is the most likely to lead to frequent shoulder injury?
Yes, the shoulder is used more frequently in various fighting styles than others. It is however impossible to say which is the most likely to result in shoulder injury due to the unknown factors of your opponent, the way you land from being knocked or thrown to the ground and the way you swing in response to an unexpected hit.
Any of these factors could result In shoulder injury. This can be due to the movement being an uncontrolled action which may lead to the shoulder being forced into a position it is unable to naturally reach resulting in injury.
To try and answer this question a bit easier I will remove the opponent and fatigue from the equation and instead just focus on the basic fighting styles. From here I will rank the styles in order of most demanding on the shoulder to least demanding as well as offer a few scenarios which could lead to shoulder injury. Not all fighting styles will be included but instead I'll give 5 examples.Martial Arts and Chances of Shoulder Injury
Boxing
Rank 1
Demand on Shoulder- Very high
Repetitive movements and intense training all focused on punching and shoulder actions both offensively and defensively.
Example of Injury
Most common injury is instability or weakness in the shoulder due to over training and training through the initial pain. This often leads to degradation at the joint and ultimately the injury becoming more serious e.g. dislocation from a missed punch.Muay Thai
Rank 2
Demand on Shoulder - Very highMuay Thai is a striking art that uses a lot of punching, kicking and grappling to overcome opponents. It places a very high demand on the shoulder due to the grappling and punching combination often putting the joint in unexpected positions when fatigued leaving it vulnerable.
Example of Injury
A large number of injuries could occur to the shoulder during a fight. An example of an injury from training could be impingement at the shoulder joint from overuses/repetitive in training.
Kickboxing
Rank 3
Despite having a large focus on the legs, kickboxing also relies heavily on jabs and uppercuts in combination with large kicking actions to defeat your opponent.
Example of Injury
A lot of injuries can occur around the lower limb, hips, knees and ankles - however the same injuries can occur in the shoulder that are mainly seen in Boxing.Brazilian Jujitsu (BJJ)
Rank 4
Demand on Shoulder - High
This fighting style is a lot more controlled relying on grappling and joint locks to overcome your opponent however it has a lot of throwing and impact landing as well as intense submissions that can be focused on the shoulder joint.
Example of Injury
A variety of unexpected injuries can occur from BJJ. The way you land after being taken to the ground can cause serious injury to the shoulder in the form of dislocation or wrenching of the joint. This can also occur from various submission techniques used within the sport.
Karate
Rank 5
Demand on Shoulder - Moderate to Low
This martial art is very disciplined and focuses heavily on technique to advance. As such injuries are less frequent than other fighting styles.
Example of Injury
Karate does utilise a lot of repetitive actions and practice, leaving the shoulder susceptible to overuse injuries. The shoulder can still be injured unexpectedly by the opponent.
It should be noted that these rankings do not mean that injuries are extremely common in these sports. In fact, more injuries occur in football and basketball than in martial arts - despite the different natures of the sports.