Signing players on loan has always been a hit-or-miss strategy for teams in the Premier League. Young players are often loaned to help them attain the experience of playing football regularly.Teams often loan out fringe or underperforming players to give them a chance at rejuvenating their careers elsewhere. Loan spells can improve players' confidence and they often return to their parent team with an increased market value.Premier League clubs sign players on loan hoping they will make a difference to their squads in the short term. Other clubs sign players on loan because they do not have the funds to land their top targets on permanent deals.The English Premier League has witnessed several clubs benefiting from player loans. Jurgen Klinsmann to Tottenham in the 1997-98 season, Henrik Larsson for Manchester United in the 2006-07 campaign and Mikel Arteta to Everton in January 2005 are a few examples of loan signings working out.On that note, let's look at the five best loan signings in the Premier League this season.#5 Joe Willock, Newcastle UnitedJoe Willock began his football career at Arsenal's youth academy. The youngster made his debut for the club in 2017 and was often used in Cup competitions for the Gunners.After failing to find a regular place in Arsenal's starting line-up during the first half of the season, Willock joined Newcastle on loan in January.Arsenal loanee Joe Willock’s last four games for Newcastle: Spurs: ⚽️West Ham: ⚽️Liverpool: ⚽️Leicester: ⚽️ pic.twitter.com/x5J6tDbGUk— B/R Football (@brfootball) May 7, 2021Many expected the 21-year-old to be used as an impact substitute by Steve Bruce, but the midfielder has contributed five goals in eleven games for Newcastle United. His record of four goals in his last four games in the league has been crucial in helping Newcastle maintain their Premier League status this season.#4 Jack Harrison, Leeds UnitedLeeds United v Manchester United - Premier LeagueThe Manchester City loanee joined Leeds United in 2018. Jack Harrison has been a key member of Marcelo Bielsa's side over the last three seasons, helping Leeds United gain promotion to the Premier League last year.🔥 After his performance against Spurs, Jack Harrison is the focus of @AMTAutoUK's 𝘚𝘱𝘰𝘵𝘭𝘪𝘨𝘩𝘵 this week pic.twitter.com/GBmpCw5cwN— Leeds United (@LUFC) May 10, 2021Harrison is heralded for his work-rate and ability to run with the football, but has never been known as a goal threat. The attacking midfielder has chipped in with seven goals and six assists in the Premier League for Leeds United this season. It seems likely that the team will look to sign Jack Harrison permanently this summer.