Basketball players hang on the rim after a dunk for two main reasons. The most common reason is to stop their forward momentum toward the rim. Another reason is to avoid landing on other players by hanging until they move out of the way. Basketball players, especially NBA players, are some of the best athletes in the world. The biggest reason for hanging on the rim is to avoid injuries while landing. Many fans mistakenly think players hang on the rim just to celebrate, which rarely happens, and can lead to a technical foul in all levels of basketball if the player pulls themselves up on the rim.
The main reason basketball players hang on the rim after a dunk is to stop or slow their momentum. Although basketball players are typically taller, they still have to create a large amount of force to be able to dunk the ball. This means, in most cases, that they will have to pick up a lot of speed to dunk.
This creates a lot of forward momentum towards the rim so the player must hold on to stop their momentum. If a player does not hold on to the rim in this scenario, they risk major injury because their forward momentum will cause them to go flying and fall to the ground. Hanging on the rim to stop forward momentum occurs multiple times per game in both the NBA and college basketball.
Another main reason players hang on the rim following a dunk is to avoid landing on other players. In most occurrences, players attempting to dunk will be met with multiple defenders trying to block their shot, which creates situations where defenders will be near the landing spot of a dunker.
In this case, a player will hang on the rim to avoid landing on any other players and avoid injuries. If the dunking player lands on a defender underneath them, they can easily twist an ankle or injure their knee. Players will hang until their opponents have cleared out from under the rim before letting go.