I am a wrestling coach at a mid-sized high school (graduating class of 300 seniors). Every year it seems one or two of my players dislocates his elbow. The football coach says this is two too many and I must be doing something wrong in my coaching. It’s light-hearted teasing but it does make me wonder. Is this typical? What are other wrestling coaches telling you?

A recent study of acute sport-related elbow dislocations may offer some information useful to you. Hand surgeons from the hospital for Special Surgery in New York City reviewed 62 You Tube videos posted of this type of injury.

They were able to analyze the videos and identify patterns and mechanisms of elbow dislocation.

They found that most acute elbow dislocations occur when the elbow is extended (relatively straight). More than two-thirds (68 per cent) of cases, the athlete’s forearm was pronated (palm down) with shoulder abduction (arm away from the side). That makes sense because the person is usually reaching the arm out to brace from a fall.

The body is rotated inwardly with the palm planted on the floor or ground. The result is external rotation of the forearm (a common position in wrestling). The arm is also usually forward with load and impact translated from the hand through the wrist and forearm to the elbow. Of course, the force must be enough to overcome stabilizing structures like ligaments (e.g., medial collateral ligament).

Dislocation events filmed and available on You Tube were seen most often during wrestling. Other common sporting events associated with elbow dislocation included skateboarding, martial arts, football, basketball, and weightlifting. Less often, elbow dislocations associated with rugby, gymnastics, and rollerblading were presented. After analysis of all the videos, there were four distinct patterns of elbow dislocation based on shoulder position, elbow position, and direction of the force.

The most common pattern (half of all acute elbow dislocations) is as described above: shoulder flexed and abducted (arm forward and out to the side) with the elbow pronated and extended (palm down and straight). The pattern is one of axial force (up through the forearm) and from the outside of the elbow inward toward the body (called a valgus force). Valgus and axial forces are enough in this pattern to tear the medial collateral ligament on the inside of the elbow (side next to the body). Wrestlers and football players had this pattern of elbow dislocation.

One-third of the cases were with shoulder extension and abduction and forearm supination (palm up) and extension. Once again, the loading forces were axial and valgus (through the forearm and across the elbow). This pattern was most often seen in inline skaters. Other much less common patterns (usually in weightlifters) were variations and combinations of these two patterns.

As this collection of You Tube videos showed, the key differences are not only sports-specific position of the arm but also (and most especially) biomechanical stability of the anterior portion of the medial collateral ligament.

They suggest further study to prove whether the presence of medial collateral ligament instability before the dislocation injury may be a contributing factor. It is possible that ligamentous instability is part of the cause and effect rather than just a result of deforming forces from the fall. Whether this type of ligamentous instability is more common in wrestlers compared with football players (perhaps as a result of previous strains) is another area where further research is needed.