Editing Smith machine

{{Short description|Weight training machine}}
[[Image:Smith machine.GIF|thumb|A Smith machine can be used for a variation of a squat.]]
The '''Smith machine''' is a [[weight machine]] used for [[weight training]]. It consists of a [[barbell]] that is fixed within steel rails allowing for only strict vertical movement. Some Smith machines have the barbell [[counterbalance]]d. The machine can be used for a wide variety of exercises including but not exclusive to; [[Squat (exercise)|squat]]s, the [[Bench press|bench press]], the [[Overhead press|shoulder press]], [[Good-morning|good mornings]] and [[Deadlift|deadlifts]].

==Use as a self-spotting device==
Behind each vertical post (runner) is a series of slots on which the barbell can be hooked. This means that unlike an ordinary barbell, the Smith machine need not be re-racked after a set of [[Strength training#Terminology|repetitions]]: it can be secured at any point. This is intended to make it safer for those who lift without a [[spotting (weight training)|spotter]], as one only needs to twist the wrist in order to lock the barbell in place in the event that the weight becomes too great. Most models also incorporate blocks, pegs, or other devices which can be adjusted to automatically stop the barbell at a predetermined minimum height.<ref name=clubindustry />

This does not fully eliminate the inherent danger in having a heavy weight on one's back, however, and may instill a false sense of confidence.  In 2001, a Smith machine user became [[quadriplegic]] when the apparatus crushed his spine.<ref name=clubindustry>{{cite web|url=https://www.clubindustry.com/mag/smith-machine-lawsuit-ends-144-million-decision|title=Smith Machine Lawsuit Ends with $14.4 Million Decision|date=September 1, 2003|publisher=Club Industry|accessdate=March 16, 2019}}</ref> [[Bench press]]ing while alone is dangerous in general, but even more so in a Smith machine; if one gets trapped under the bar, it cannot be rolled or tipped sideways off one's chest or neck, which has led to at least one fatality.<ref>{{Cite web|url=https://www.couriermail.com.au/news/queensland/bray-park-teen-ben-shaw-donates-organs-after-fatal-weightlifting-accident/news-story/2d3ca08121be796b1bd1383e64d38436|title=Ben's generous last gift of life|date=October 1, 2017|website=www.couriermail.com.au}}</ref>

==Advantages and disadvantages==
Use of the Smith machine is frowned upon by many strength training devotees as it forces the user to adopt an unnatural straight-up-and-down "bar path". This unnatural movement can cause [[shear stress]] on the knees and/or back when squatting or shoulders (if [[bench press|pressing]]).<ref>{{cite web|url=http://www.dovemed.com/current-medical-news/4-reasons-bypass-smith-machine/|title=4 Reasons to Bypass the Smith Machine|publisher=dovemed.com|date=July 23, 2015|accessdate=March 16, 2019}}</ref><ref>{{cite web|url=https://bretcontreras.com/machines-vs-free-weights-more-research-is-needed/|title=Machines Vs. Free Weights: More Research Is Needed|author=Bret Contreras|publisher=bretcontreras.com|date=July 16, 2013|accessdate=March 16, 2019}}</ref><ref>{{cite web|url=https://www.ironmanmagazine.com/the-brothers-grimm-3/|title=The Brothers Grimm|author=Stuart McRobert|publisher=[[Iron Man (magazine)|Iron Man]]|date=February 12, 2008|accessdate=March 16, 2019}}</ref>

The constrained movement of the bar also reduces the role that stabilizing muscles play versus an exercise using [[Weight training#Free weights|free weights]]. This may allow heavier weights to be lifted, at the expense of engaging less muscle mass overall. It is also hard to keep an accurate training log because manufacturers do not usually indicate bar weights.<ref>{{cite web|url=https://www.tworepcave.com/6100/how-much-does-a-smith-machine-bar-weigh/|title=How Much Does a Smith Machine Bar Weigh?|author=David Kiesling|publisher=tworepcave.com|date=January 20, 2019|accessdate=March 16, 2019}}</ref>

As with other [[exercise machines]], the Smith machine is often preferred by casual or inexperienced strength trainees who do not know how to safely perform [[Weight training#Free weights|free weight]] exercises involving heavy weights.<ref>{{cite book|url=https://books.google.com/books?id=cfb4cBIHhK0C&pg=PA15|title=Inspire Women to Fitness|year=2003|publisher=IDEA Health & Fitness Association|isbn=978-1-887781-29-9|page=15}}</ref><ref>{{cite web|url=http://www.menshealth.co.uk/building-muscle/get-big/should-i-use-weight-machines|title=Should I use weight machines?|author=Tom Banham|publisher=[[Men's Health]]|date=August 19, 2014|accessdate=March 16, 2019}}</ref> Many [[gym]]s cater to casual trainees and thus may provide Smith machines instead of [[power rack]]s, which are a piece of equipment critical for safely performing squats and other barbell-based free weight exercises.

The Smith machine does have some advocates amongst experienced trainees, however.  The "bar path" issue is minimized for exercises involving a short range of travel such as [[calf raise]]s and [[shoulder shrug|shrugs]].  It is potentially good for performing exercise variations when progress has slowed using other exercise forms, although care must be taken to avoid joint stress issues.  The removal of stabilizing muscles as a factor can also allow one to increase the intensity applied to primary muscles.<ref>{{cite web|url=https://www.t-nation.com/training/why-i-love-the-smith-machine|title=Why I Love the Smith Machine|author=John Meadows|publisher=t-nation.com|date=January 9, 2012|accessdate=March 16, 2019}}</ref><ref>{{cite web|url=https://www.t-nation.com/training/the-most-hated-machine-in-the-gym|title=The Most Hated Machine in the Gym|author=Paul Carter|publisher=t-nation.com|date=July 12, 2016|accessdate=March 16, 2019}}</ref>

== 3D Smith machine ==
A conventional Smith machine has one [[degrees of freedom (mechanics)|degree of freedom]] – the bar can move up and down in a straight line along a vertical track. (Rolling the bar is also typically used to activate the safety locks.) Some variant designs allow an additional degree of freedom – forward and back – while still keeping the bar from rotating or moving side to side.  These machines are sometimes called "3D Smith machines" or "Jones Smith machines".

A few designs, such as Shermworks' "Free Spotter" or TuffStuff's "XPT Training System", permit almost all degrees of freedom while still incorporating user-activated safety catches (as opposed to the passive, pre-set safeties of a [[power rack]]).

==Origin and history==
The Smith machine was invented by American [[Jack LaLanne]], who rigged up a sliding apparatus in his gym in the 1950s. It was spotted by Rudy Smith, who commissioned Paul Martin to improve it.<ref name=saga>{{cite book|chapter-url=https://books.google.com/books?id=4TkpDwAAQBAJ&pg=PA49|chapter=The Machine Age, 1960s-1970s|title=Making the American Body: The Remarkable Saga of the Men and Women Whose Feats, Feuds, and Passions Shaped Fitness History|page=49|last=Black|first=Jonathan|year=2013|publisher=University of Nebraska Press|isbn=978-0-8032-4370-5}}</ref><ref name=deseret>{{cite web|url=https://www.deseret.com/2010/7/12/20127323/obituary-smith-rudolph/|title=Obituary: Smith, Rudolph|publisher=[[Deseret News]]|date=July 12, 2010|access-date=March 16, 2019}}</ref> Smith then installed the modified model in a gym he was managing at the time, [[Vic Tanny]]'s gym in Los Angeles.<ref>{{cite web|url=https://www.oldtimestrongman.com/blog/2013/02/08/the-smith-machine/|title=The Smith Machine|author=John Wood|publisher=oldtimestrongman.com|date=February 8, 2013|accessdate=March 16, 2019}}</ref> By the end of the 1950s, Rudy Smith was an executive in Tanny's chain of gyms, and the Smith machine was being manufactured and sold more widely.<ref name=saga/><ref name=deseret/>

==Effectiveness==
Research published in December 2009 reported that free weights triggered 43% more activation of the muscles than a Smith machine when performing squats.<ref>{{cite journal |last1=Schwanbeck |first1=S |last2=Chilibeck |first2=P. D. |last3=Binsted |first3=G. |date=December 2009 |title=A comparison of free weight squat to Smith machine squat using electromyography |journal=[[The Journal of Strength & Conditioning Research]]|doi=10.1519/JSC.0b013e3181b1b181 |volume=23 |issue=9 |pages=2588–2591 |pmid=19855308|doi-access=free }}</ref>

==References==
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{{DEFAULTSORT:Smith Machine}}
[[Category:Weight training equipment]]