(written from a Production point of view)
Stephen "Steve" Andrew Blalock is a stuntman and stunt coordinator who worked on several Star Trek series and Star Trek films. He started his Star Trek connection as stand-in for Leonard Nimoy on Star Trek II: The Wrath of Khan and Star Trek III: The Search for Spock and also performed stunts in these films. He later performed stunts in episodes of Star Trek: The Next Generation, Star Trek: Voyager, and Star Trek: Enterprise as well as in the films Star Trek: Insurrection and Star Trek.
Blalock was among the stunt cast who won a Screen Actors Guild Award in the category Outstanding Performance by a Stunt Ensemble in a Motion Picture for Star Trek in 2010. He shared this award with Robert Alonzo, Daniel Arrias, Sala Baker, Ben Bray, Mark Chadwick, Ilram Choi, Zack Duhame, Peter Epstein, Jeremy Fitzgerald, Terry Jackson, Craig Jensen, Paul Lacovara, Rob Mars, Mike Massa, Heidi Moneymaker, Mike Mukatis, Courtney Munch, Kimberly Murphy, Chris Palermo, Jim Palmer, Eddie Perez, Dan Plum, Damion Poitier, Susan Purkhiser, Dennis Scott, Chris Torres, Webster Whinery, Jr., and Marcus Young.
Several of his costumes worn in Star Trek were later sold off on the It's A Wrap! sale and auction on eBay including the costumes from the episodes "Impulse", "The Xindi", and "Canamar".    The latter one was also worn in VOY: "Resistance" and by Steve Rankin in ENT: "Demons". The operations division Starfleet uniform from "Worst Case Scenario" and "Equinox" as well as the Maquis vest from "Worst Case Scenario" were also sold off on eBay. The vest was previously worn by John Franklyn-Robbins in TNG: "Preemptive Strike".   Two of his earlier costumes, a white and a red radiation suit, worn in Star Trek II and Star Trek III were also among the auctioned costumes.  
Blalock was a semi-pro soccer player before he and his wife Michelle Louise moved from Northern California to Santa Monica in 1978. He received his SAG card through the Extra's Guild in 1981 and attended Paul Stader's Stunt School in Santa Monica, California.
Among his earlier stunt work are the two comedies Stripes (1981, with Mary Peters, Carol Daniels, and John Cade) and Revenge of the Nerds (1984, with John Cade, Corey Michael Eubanks, and Danny Rogers), both stunt coordinated by Terry James, and the television series Buck Rogers in the 25th Century (1981).
In 1985, Blalock started to work for Stunt Coordinators Vince Deadrick, Jr. and Buddy Joe Hooker as stunt double for Richard Dean Anderson on the television series MacGyver. Besides doubling Anderson, he also had stunt acting parts on the series (1987-1990) where he worked with Bruce McGill and directors Cliff Bole and Charles Correll. He also worked as Anderson's stunt double on Michael Piller's science fiction/Western series Legend (1995, co-starring John de Lancie) and on the television thriller Pandora's Clock (1996, with Ron Sarchian and coordinated by Vince Deadrick, Jr.). 
Blalock doubled Lorenzo Lamas in the television series Air America (1998-1999, working with Manny Perry, Henry Kingi, Jr., Joey Anaya, Dan Plum, Hiro Koda, Hugh Aodh O'Brien, Tim Rigby, and Charlie Picerni), The Immortal (2000-2001, working with Dominic Keating), and The Bold and the Beautiful (2004 and 2006). Other actors he doubled for include Rick Aiello in the science fiction Western Ground Zero Texas (1993, coordinated by Hubie Kerns, Jr.), Thomas Haden Church in the comedy George of the Jungle (1997, coordinated by Phil Adams), Christopher Eccleston in the thriller Gone in Sixty Seconds (2000, coordinated by Chuck Picerni, Jr.), Ronn Moss and Don Diamont in The Bold and the Beautiful (1997-2015), Matthew Fox on the television series Lost (2004-2005) and Haunted (2002-2008), and Kyle MacLachlan in the Desperate Housewives episode "City on Fire" (2008, with Alina Andrei, Shawn Crowder, Bevin Kaye, Scott Leva, and Kortney Manns and coordinated by Wally Crowder).
He was one of the impostors in the television action comedy Ring of the Musketeers (1992, with John Rhys-Davies, Corbin Bernsen, Richard E. Butler, Erik Cord, Catherine Coulson, Chris Doyle, Scott Jaeck, Loren Janes, Julius LeFlore, Marie Marshall, John Paragon, Branscombe Richmond, Jim Wilkey, Patricia Tallman, and Tom Morga), one of Mr. Freeze's Ice Thugs in the comic adaptation Batman & Robin (1997, along with Mark Chadwick, Dennis Keiffer, Jean-Luc Martin, Jim Palmer, and Paul Sklar), a Vampire Master in John Carpenter's horror film Vampires (1998, with Anita Hart, Marjean Holden, and Cris Thomas-Palomino), a cop in the drama The Deep End of the Ocean (1999, with Mike Watson and coordinated by Allan Graf), and Batman's stunt double in the television comedy Return to the Batcave: The Misadventures of Adam and Burt (2003, coordinated by Michael Cassidy).
Other stunt work includes the thriller Black Moon Rising (1986, coordinated by Bud Davis), the comedy Miracles (1986, with Greg Gault and Don Pulford), the comedy She's Out of Control (1989, coordinated by Wally Crowder), the television series One West Waikiki (1993, with Gates McFadden), the action drama Blown Away (1994, coordinated by Vince Deadrick, Jr.), the comedy Blankman (1994, coordinated by William Washington), the crime comedy A Low Down Dirty Shame (1994), the television movie Bionic Ever After? (1994, with Joey Box and coordinated by Vince Deadrick, Jr.), the thriller The Set Up (1995, coordinated by Ben Scott), the drama Showgirls (1995), the Western Wild Bill (1995, coordinated by Allan Graf), the drama Jerry Maguire (1996), the comedy Vegas Vacation (1997), the thriller Conspiracy Theory (1997), the crime drama Double Tap (1997, coordinated by Michael J. Sarna), the crime drama The Newton Boys (1998), the fantasy drama City of Angels (1998), the sport comedy BASEketball (1998), the crime drama Letters from a Killer (1998, coordinated by Bud Davis), the thriller Arlington Road (1999), and the drama Here on Earth (2000, coordinated by Ron Stein).
Blalock also performed stunts in the sport comedy The Replacements (2000, coordinated by Allan Graf), the science fiction remake The Time Machine (2002, coordinated by Jeff Imada), the war drama Master and Commander: The Far Side of the World (2003), the action comedy The Whole Ten Yards (2004, coordinated by Rick Avery), the romance Raising Helen (2004, coordinated by Gary Combs), the science fiction film Serenity (2005), the television movie Drake and Josh Go Hollywood (2006, with Edward Conna, Shawn Crowder, Jeremy Fry, Mark Ginther, Rosine "Ace" Hatem, and Sonny Surowiec, and coordinated by Vince Deadrick, Jr.), the action sequel Mission: Impossible III (2006), the thriller Serpahim Falls (2006, coordinated by Bud Davis), the horror sequel Paranormal Activity 2 (2010, with Jennifer Caputo, Craig Jensen, Paul Lacovara, J.J. Perry, and Ator Tamras and coordinated by Dennis Scott and Rob King), and episodes of Zoey 101 (2006, with Mike Cassidy and Vince Deadrick, Jr.) and Westworld (2016, coordinated by Mike Watson).
Among his work as stunt coordinator are the fantasy film The Spiderwick Chronicles (2008, with Katina Waters and co-stunt coordinator Joey Box) and episodes of The Bold and the Beautiful (2003 and 2005, with Thom Williams and Michael Cassidy).
More recently, Blalock worked as double for Lorenzo Lamas on the action drama BorderCross (2017, with Mykle McCoslin), as stunt double for Ingo Rademacher on The Bold and the Beautiful (2018, with Oliver Keller and Tom McComas and coordinated by Mike Cassidy), and as additional stunt coordinator on the action series Shadow Wolves (2018, with Nick Hermz and Panuvat Anthony Nanakornpanom and stunt coordinator Clint Lilley).