Model of Walking

\[Theta][t_] := (Sin[t]/Sin[1]) (Pi/8);
body[t_] := {(2 Sin[Pi/8]) Floor[t] + Sin[\[Theta][T[t]]],
   Cos[\[Theta][T[t]]]};
T[t_] := (2 (t - Floor[t]) - 1);
Manipulate[
 Show[Graphics[Join[
    {Thick, Line[{{2 Sin[Pi/8] Floor[t], 0}, body[t]}], Purple,
     PointSize[Large], Point[body[t]]}
    ], PlotRange -> {{-1, 4}, {0, 1.2}}],
  ParametricPlot[body[\[Tau]], {\[Tau], -10^-5, t},
   PlotStyle -> Directive[Darker@Orange, Thick]]]
 , {t, 0, 4.99}]