You should be careful to not bump into others.
Jack was taking part in a marathon and was in the starting line with a large crowd of runners.
Jack wants to get ahead of the crowd of runners.
Jack waits until the crowd disperses and weaves his way through the other runners.
Jack pushes his way through the crowd of runners, jostling other runners as he tried to get ahead.
Jack is able to get ahead of the crowd and set a good running pace.
The other runners get angry at Jack's behavior and pushes him back.