For Liverpool fans watching the Champion's League final, the moment Mo Salah went down injured in the first half was a heart-stopping moment.
In this article our chiropractors will explain what happened to Mo Salah and whether we can expect to see him at the World Cup.
Mo Salah's injury occurred as a result of a fall whilst competing for the ball with Real Madrid's Sergio Ramos.
While Mo's right arm was trapped under Ramos as they fell, it was his left shoulder that he injured.
The clip below shows how both players fell simultaneously, rolling as they hit the ground, with Mo Salah landing on the point of his left shoulder.
Early press reports describe Mo Salah's injury as a shoulder dislocation.
This is probably, at least in part, incorrect.
When we speak of a dislocated shoulder, we mean the big ball and socket joint (glenohumeral joint).
A shoulder dislocation is very unusual following a fall onto the point of the shoulder, normally occurring when the arm is in a throwing or outstretched position. Often deformity can be seen at the moment of trauma and, unless the shoulder immediately relocates itself, after the injury.
Athletes who have dislocated a shoulder are unable to move their arm at all afterwards.
So we can rule out a glenohumeral joint dislocation, almost just from the way Mo Salah fell.
A more likely possibility is whether Mo Salah dislocated his AC joint.
The AC joint (acromio-clavicular joint), is the point where your collar bone and shoulder blade meet.
It is very vulnerable to trauma caused by a fall onto the point of the shoulder.
AC joint injuries are split into six categories, dependant on severity. But, broadly speaking, we can describe them in two ways; an AC joint sprain and an AC joint dislocation.
If we look at the moment Mo Salah's injury occurred, it is obvious to see that almost all his body-weight fell onto the point of his left shoulder. This point is called the acromion.
Force through the acromion stretches the ligaments that attach it to the collar bone. With enough force, these ligaments can rupture, leading to a dislocation.
A dislocated AC joint cannot relocate, so when the medics came onto the pitch to assess Mo Salah they would have seen a very obvious bony lump had he dislocated his AC joint.
Pressure on the end of Mo Salah's collarbone would have caused it to sink downwards like a piano key being pressed, making an AC joint dislocation one of the easiest injuries to diagnose on the field of play.
At this point, no responsible medic would allow an athlete to continue play.
Also, we can see Mo Salah is able to move without his arm supported and even run shortly after injury. This would be very unusual following an AC joint dislocation.
So this brings us to the most likely diagnosis for Mo Salah being an AC joint sprain.
The mechanism of injury is exactly the same as an AC dislocation, but the ligaments don’t rupture.
AC joint sprains are painful, but the arm can be moved and held without a support, and they are difficult to diagnose on the pitch because there is not deformity and only mild instability of the collar bone.
In this case, medics would advise the player continue unless he felt that his pain was limiting his performance.
After Mo Salah fell and injured his shoulder, medics quickly came onto the pitch. They examined his shoulder, paying particular attention to the AC joint.
Mo Salah was then allowed to continue playing for another few minutes before calling for the medics again and removing himself from the field of play.
Unless the medics missed a dislocated AC joint on first examination, which is extremely difficult to do, we can therefore conclude that Mo Salah has sprained and not dislocated his acromioclavicular joint.
This allows us to speculate on how soon Mo Salah is likely to recover and return to play.
As with all joint sprains, AC joint sprains are treated without surgery using manual therapy and exercise.
The timeframe for recovery varies between one and six weeks, depending on the severity.
However, it is very likely that Mo Salah will be able to return to play at some point before complete recovery because of the low risk of re-injury posed by football.
In this chiropractor's opinion, it is very possible that Mo Salah will play some part in the World Cup.
However, that may depend on the Egypt international's teammates ensuring his country stay in the competition long enough.
In the worst case scenario, Mo Salah may miss the opening round of the competition, but stands a very good chance of playing a part if his country progress beyond this stage.
Since the risk of re-injury to Mo Salah is relatively low, and his value to his team is so high, medical professionals may be under pressure to do everything they can to ensure he is able to play from the get go.
This means controlling Mo's symptoms so that he can move without being affected. Typically, a steroid injection would be used to achieve this.
Unfortunately, interventions such as steroid injections, while easing player symptoms, come at the expense of long term player welfare.
Joint sprains rely on the body's inflammatory response to be able to heal fully and a steroid injection would interrupt this process leading to incomplete recovery and a higher likelihood of problems with the shoulder in the future.
This is the unhappy trade-off that affects many professional athletes.