The phrase "a significant hand" is correct and usable in written English.
It can be used to describe someone who plays an important role or has a major influence in a situation or event.
Example: "She played a significant hand in the success of the project, guiding the team through every challenge."
Alternatives: "a major role" or "a key part".
Ms. Beber had a significant hand in promoting the Helmsley hotel empire.
On the other hand, Sugababes have always insisted they have a significant hand in writing their own material.
Alan Wainwright is a whistleblower who appears to have had a significant hand in changing government policy.
Often toiling behind the scenes, Mr. Carter had a significant hand in many historic legal challenges to racial discrimination in the postwar years.
He had had a significant hand in the evolution of World in Action, Brideshead Revisited and Coronation Street, though he admitted that originally he had doubted whether those broad Lancashire accents would ever be accepted down south.
In fact, Malians feel that elections are being thrust on them – "governed by Paris", as one commentator put it – by the colonial power that had a significant hand in creating the current national crisis in the first place.
He will doubtless play a more significant hand during the upcoming Test series in Sri Lanka this winter.
Mr Jones, 18, who was trapped in the driver's seat, was also attacked with a crowbar, causing "significant hand and facial injuries", said Littleborough RUFC.
The former Aston Villa midfielder scored the opener against Palace with a well hit shot from distance, though, for the second successive game, a Wayne Hennessey blunder offered a significant helping hand.
Tech-savvy businesses will gain a significant upper hand in 2014 as they capitalize on the mobile device trend by implementing mobile content marketing strategies.
Or, rather, it replaced them as the system-level mapping resource in iOS 6 with their own tool, built partly in-house and with a significant helping hand from GPS hardware and software-maker TomTom.
