How can I keep the weld from freezing my character?

When I weld a backpack to my torso it holds my character and the backpack in the position of the backpack. Nothing is anchored and it makes me float and i cant move anything and shift lock doesn't even work. Also please don't tell me to check if its anchored it isn't.

https://gyazo.com/3b5d28ead0e866d807c8c38b2285ad85(visual help)

for a,b in pairs(Player.Character.RockPack:GetChildren()) do
if b.Name == "Base" or b.Name == "Part" then
    weld = Instance.new("ManualWeld")
    weld.Part0 = Player.Character.Torso
    weld.Part1 = b
    weld.C1 = b.CFrame:toObjectSpace(Player.Character.RockPack.Base.CFrame)
    weld.Parent = Player.Character.RockPack.Base
    weld.C0 = CFrame.new(0,-.5,1.1)

b.TopSurface = ("SmoothNoOutlines")
    b.BottomSurface = ("SmoothNoOutlines")
    b.BackSurface = ("SmoothNoOutlines")
    b.FrontSurface = ("SmoothNoOutlines")
    b.RightSurface = ("SmoothNoOutlines")
    b.LeftSurface = ("SmoothNoOutlines")
    b.Material = ("SmoothPlastic")

end
end