12 January 2016 Last updated at 09:50 GMT
In an era when an 80-120 hour week was seen as standard for junior doctors, they opted to not work beyond a  40-hour week.
Pay was another major issue at the heart of strike action in 1975. The rate of pay was reduced by about two-thirds after the first 44 hours of the week.
The junior doctors' strike began across England at 08:00 GMT on Tuesday 12 January 2016, with junior doctors only providing emergency care.
Weekend pay and concerns about safeguards to stop hospitals over-working doctors are the issues at stake.

A commission of inquiry was set up five years ago to look into the allegations surrounding the 1999 government deal.
Mr Zuma was sacked as deputy president in 2005 after his financial adviser was convicted of corruption over the deal.
The president on Thursday announced the inquiry had found no evidence against any government officials of the time.
He said money had been paid for consultancy services "and nothing else".
The allegations relate to the government's purchase of 30bn rand (then $5bn) worth of fighter jets, helicopters, submarines and warships in 1999.
Mr Zuma was sacked as deputy president in 2005 after his then financial adviser Schabir Shaik was found guilty of trying to solicit bribes for his boss from an arms company.
Mr Zuma always denied the allegations, and in 2009 prosecutors dropped 700 charges of fraud, corruption and racketeering against him, just weeks before elections which saw him become president.
But his critics refused to let the issue drop, so in 2011 he agreed to appoint a commission to investigate the arms deal, which concluded its enquiries at the end of last year.
This is not the only controversy he has been implicated in. Last month South Africa's highest court ruled he had violated the constitution by failing to repay government money for a luxurious upgrade on his private residence.
The investigation, which took four years to conclude, found no evidence of widespread bribery, corruption and fraud in the selection of the preferred bidder to supply the arms, or of payment of bribes to officials in the awarding of the deal.
The three-volume report on the investigation, which will be made public, has not made any recommendations for further investigations, leading some to believe the ANC is covering up for its leader and other officials who were implicated.
The opposition Democratic Alliance believes the Arms Procurement Commission made no real effort to investigate the allegations contained in crucial documents. It has described the final report as a massive disappointment because no-one will face criminal charges.

Gordon Thompson, of Waddon Road, Croydon, was charged with arson with intent to endanger life and arson.
He was also charged with two counts of burglary and one count of violent disorder in the town centre. He was remanded in custody to appear at Croydon Magistrates' Court on Monday.
A man aged 21 and 15-year-old boy have already been arrested over the fire.
They have been released on bail.
A 25-year-old man who was arrested on Wednesday was later released without charge.
Violence erupted in Croydon on Monday night after two nights of trouble in other parts of the capital.
Demolition has begun on the 150-year-old furniture store in south London.
The Reeves family, who owned House of Reeves Furniture, hired a demolition crew so the remains of their ruined furniture store could be cleared.
The last major strike over pay and conditions by junior doctors was over 40 years ago in 1975.
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South African President Jacob Zuma says an inquiry into an arms deal worth billions of dollars has found no evidence of corruption or fraud.
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A 33-year-old man has been charged with starting a fire which destroyed the Reeves Furniture Store in Croydon.