Rocky Balboa

Former Philadelphia boxer Rocky Balboa has been retired from boxing for 16 years and lives a quiet life as a widower following the death of his wife, Adrian Pennino Balboa, due to cancer four years earlier. He runs a small but successful Italian restaurant named after her, where he regales his patrons with stories of his past. He also battles personal demons involving his grief over Adrian's death, the changing times, and his eroding relationship with his son Robert, a struggling corporate employee. Paul "Paulie" Pennino, Rocky's brother-in-law and best friend, continues to keep by his side, but is tired of reliving the past.
Late one night, Rocky reunites with a much-older "Little" Marie, a once mischievous neighborhood girl Rocky met when she was a child, now working as a bartender at Rocky's former neighborhood bar, the Lucky Seven. She is a single parent of a teenaged son born out of wedlock: Stephenson, nicknamed "Steps". Rocky's friendship with the two blossoms over the following weeks. Marie becomes a hostess at his restaurant and Steps takes to him as a father figure.
Meanwhile, on the professional boxing circuit, Mason "The Line" Dixon reigns as the undisputed yet unpopular world heavyweight champion. ESPN broadcasts a computer simulation of a fight between Rocky (in his prime) and Mason â likened to a modern-day version of The Super Fight, a 1970 computer simulation of a 15-round fight between Rocky Marciano and Muhammad Ali in their prime (that Marciano "won" by a KO in the 13th round) â which ends in a controversial KO victory for Balboa, riling the champ. In contrast, the simulation inspires Rocky to take up boxing again, an intention that goes public when he successfully renews his license. Dixon's promoters pitch the idea of holding a charity exhibition bout at the Mandalay Bay Resort and Casino in Las Vegas to bolster Dixon's falling popularity.
With some hesitation, both men agree to the match, creating a media buzz that stabs at Rocky's has-been status and Dixon's credibility, Dixon having yet to face a challenging opponent. Robert tries to discourage Rocky from fighting, blaming his own personal failings on his father's celebrity shadow, but Rocky rebukes him with some advice: that to succeed in life, "It ain't about how hard you hit; it's about how hard you can get hit and keep moving forward," and that blaming others won't help him. The next day, father and son meet at Adrian's grave and reconcile; Robert has quit his job to be at Rocky's side. Rocky sets straight to training with Apollo Creed's old trainer Duke Evers, who quickly surmises that the slow and arthritic Rocky cannot depend on sparring as he did in the past, and can only compete by building his strength and punching power as much as possible, focusing on "blunt force trauma" to pound his opponent.
The fight becomes an HBO Pay-per-View event billed as "Will Vs. Skill." Rocky is given little chance, and a TV commentator jokes that it is being called an "exhibition" because it can't be called an "execution." But Rocky enters the ring to the tune of Frank Sinatra's "High Hopes" and wearing the same gold-trimmed black trunks he wore when he beat Apollo Creed and the large crowd is clearly in his corner.
Dixon easily dominates the first round, only to injure his left hand against Rocky's hip in the second. Rocky makes a dramatic comeback; he manages to knock Dixon down once and then continues to surprise the audience with his prowess and chin against the younger and faster fighter. Dixon, unprepared for Rocky's resilience, sends Rocky to one knee in the final round, but the elder fighter pulls himself to his feet for one last assault. The two continue to punish each other until the end. Rocky thanks an appreciative Dixon for the fight and leaves the ring to the adulation of the crowd before the result is even announced. It is a win for Mason Dixon by a narrow split decision, but Rocky clearly does not mind.
Back in Philadelphia, Rocky brings roses to Adrian's grave again, thanking her for helping him.

Question: In the movie, what body part does Dixon injure in the second round?
Answer: left hand