Equilibrium equations:
ΣFy=0=F(feet)+F(hands)-(9.81m/s^2*90kg)
ΣM=0=1.75m*cos(20)*F(hands)-1.1667m*cos(20)*
(9.81m/s^2*90kg)

Solving for F(hands) we get:
F(hands)= 588.6N

Now we can solve for F(feet) and we get:
F(feet)=294.3N

Now we can compare to the total force to find what percent of our body we are lifting.
F(hands)/(mg)*100%=588.6/(90*9.81)*100%=66.7%