Fred Claus

A baby is born, and within a few minutes of his birth, he starts saying: "Ho, ho, ho!". Mother Claus calls her son, Frederick, over to meet his new brother, whom she has decided to name Nicholas. Mother Claus lovingly refers to the new baby as her little Saint Nick. During Christmas, when Nick opens his gifts including Fred's, he decides to give them away to orphans which makes Fred angry. Mother Claus advises Fred to be a better person by stating he should be more like his brother; this in turn causes Fred to resent Nick. Feeling isolated, Fred often climbs a tree to confide his problems in a bird. On one occasion, Nick cuts down the tree, saying that now Fred can bring it inside since he liked it so much. However, the birdhouse Fred's confidant lived in is smashed, causing the bird to leave; this causes a temporary rift between Fred and Nick.
In the present-day, it is revealed that when Nick becomes a saint due to all his good deeds, he, Fred, and Mother and Father Claus become frozen in time, never to age. Nick has become the modern-day Santa Claus, giving gifts to people and Fred works as a repossession agent in Chicago to take them away. Fred meets his girlfriend, Wanda, who gets mad at him for forgetting that her birthday was the next day. Wanda refers to a previous birthday where Fred promised to take her to France. When Fred gets back to his own apartment, he packs up when a young orphan boy named Samuel "Slam" Gibbons comes in. Slam talks about wanting a puppy named Macaroni for Christmas. After Fred gets arrested, he calls his brother for $5,000 bail money. He also asks for an additional $50,000 for a get rich quick scheme. Nick agrees to give him the bail money, but tells him that if he wants the $50,000, he has to come to the North Pole and work for it. Soon after, an elf named Willie shows up to take Fred to the North Pole. He is the head elf and has a crush on Santa's Little Helper, Charlene. Once Fred and Willie arrive at the North Pole, Nick welcomes Fred and shows him around the North Pole. There is a snow globe in the main area of the workshop, where you can say any person's name and see if they are being naughty or nice. While Fred starts working, Nick introduces Clyde Northcut, an efficiency expert who has come to evaluate the North Pole. Clyde takes Nick to the workshop and on the way tells Nick that he has three strikes. If Nick gets three strikes, the workshop will be shut down for good. Meanwhile the workshop is in a state of chaos because of Fred, and Clyde says that Nick's inability to control his work staff is strike one. That night at dinnertime, Nick convinces Fred to come to dinner with Mother and Father Claus and Clyde. Sitting down at the dinner table, Mother Claus continues to praise Nick, while Fred storms out and heads to Frosty's Tavern, an elf bar, where he meets Willie, who discusses his lack of self-confidence regarding Charlene. Fred teaches Willie to dance, and Willie then falls down in front of Charlene, embarrassing himself. A pep talk by Fred later lifts his spirits. Meanwhile, Clyde deliberately sabotages the mail sorting department by shredding countless children's letters, which later gives Nick a second strike. Believing that Fred is putting Nick under stress, a family meeting is called (which Fred was tied up and taken to) with Wanda present, and Fred leaves by saying that therapy is for families who want to be together, and their family does not have that problem. When Slam is placed at the top of the most naughty list, Fred understands that Slam has just had it hard and is not naughty. He then stamps every kids' description as nice.
Furious at what Fred has done wrong, Nick ends up fighting with him, in which Nick injures his back. Angry with Nick, Fred leaves the North Pole with his $50,000, but Nick gives Fred a present to take with him. Fred waits until he returns home to open the gift, which is a birdhouse, a replacement for the one on the tree, and a note from Nick which says, "I'm sorry for cutting down your tree. Love, Nick." Fred is confused and enters a Siblings Anonymous meeting. At the end, Bill Clinton's younger half-brother, Roger Clinton Jr, makes a speech about his brother's success. Back at the North Pole, it looks like Christmas is lost. Nick is in bed and cannot make his Christmas Eve journey of delivering presents. Fred replaces him. Willie reminds Fred that, according to a long-standing rule, only a member of the Claus family can deliver the presents and Fred qualifies. Fred begins delivering presents to children around the world and Willie joins him to assist with the flying of the sleigh and the navigation. In a humorous scene during his deliveries, Fred mistakenly goes down the chimney of a house belonging to a Jewish family and they respond by offering him Challah and knishes. Meanwhile, Clyde sabotages their efforts at midnight by shutting off the power, which was the only way for the North Pole to communicate to Fred and Willie, helping them navigate. While Fred and Willie attempt to finish delivering the gifts for the children, Nick talks to Clyde by realizing that when he was a boy, Clyde did not get what he wanted from Nick because he would act up due to bullying, which resulted in him growing up to be the man he is. Nick realizes, thanks to Fred, that his definition of naughty was flawed. Nick makes peace with him by giving Clyde the Superman cape he wanted as a kid but never got. Fred stops by the foster home to visit Slam and bring him the puppy (Macaroni) he wanted. Fred faces away from Slam to hide his identity and explains to Slam that he should become a better person. As the rest of the elves anxiously wait in the tavern, Willie marches in and, with newfound confidence, he walks up to Charlene, grabs a chair to stand on, and kisses her. After Fred announces that Christmas has been saved, everyone gathers around the giant snow globe to watch the children of the world open their presents. Nick tells Fred that he is the best big brother anybody could ever ask for, and they finally make amends. Fred returns to Wanda's house and she is initially upset to see him and tells him to leave. He refuses and states that he is moving in with her. He gives her a present. Wanda opens it to find a teddy bear holding a French flag. That night, Fred takes Wanda to France in Santa's sleigh, and they circle around the Eiffel Tower ("It's a company car. It's one of the perks." says Fred). The two continue dating, and Charlene and Willie are now happy together. By next Christmas, Slam is adopted, but Fred never stops watching out for him. As for Clyde, Nick hires him as an efficiency consultant and he teaches the elves how to use a spreadsheet. Nick and Mrs. Claus, as well as Nick and Fred's parents visit Fred's and Wanda's house for Christmas. It is evident that Fred and his mom have grown closer. Fred has also become a true Claus; while Nick has lost a bit of weight, Fred has gained some. The movie ends by showing the bird house hung up outside Fred's window, and a bird, who looks like the one Fred befriended, perched on it.

Question: Who's back does Fred injure?
Answer: Nick