Continue playing animation after jumping?

Okay, so I have a script that when you're walking and press shift it plays my running animation and increases the characters speed. What I want though is if after you jump and land and are still holding shift it starts the animation again so it's not just doing the walk animation. The reason I don't wanna just deal with pressing shift again is that in the game you need to keep the momentum or you'll most likely have to start over. Heres what I got:

local Player = game.Players.LocalPlayer
    local Character = workspace:WaitForChild(Player.Name)
        local Humanoid = Character:WaitForChild('Humanoid')

local RunAnimation = Instance.new('Animation')
RunAnimation = game.Workspace.Flip.Run
RAnimation = Humanoid:LoadAnimation(RunAnimation)

Running = false

function Handler(BindName, InputState)
    if InputState == Enum.UserInputState.Begin and BindName == 'RunBind' then
        Running = true
        Humanoid.WalkSpeed = 50
    elseif InputState == Enum.UserInputState.End and BindName == 'RunBind' then
        Running = false
        if RAnimation.IsPlaying then
            RAnimation:Stop()
        end
        Humanoid.WalkSpeed = 16
    end
end

Humanoid.Running:connect(function(Speed)
    if Speed >= 10 and Running and not RAnimation.IsPlaying then
        RAnimation:Play()
        Humanoid.WalkSpeed = 50
    elseif Speed >= 10 and not Running and RAnimation.IsPlaying then
        RAnimation:Stop()
        Humanoid.WalkSpeed = 16
    elseif Speed < 10 and RAnimation.IsPlaying then
        RAnimation:Stop()
        Humanoid.WalkSpeed = 16
    end
end)

Humanoid.Changed:connect(function()
    if ... then -- I tried doing Humanoid:GetState() == Enum.HumanoidStateType.Freefall and Humanoid:GetState() == Enum.HumanoidStateType.FallingDown and Humanoid:GetState() == Enum.HumanoidStateType.Landed here  
        wait(1)
        RAnimation:Play()
    end
end)

game:GetService('ContextActionService'):BindAction('RunBind', Handler, true, Enum.KeyCode.LeftShift)