The above equation is known as a linear non-homogeneous
displacement loop closure equation in complex unknowns [X.sub.1], [X.sub.2], [X.sub.3], [X.sub.4] and has complex coefficients [e.sup.i[[theta].sub.j]], [e.sup.i[[omega].sub.j]] and [e.sup.i[[lambda].sub.j]].
(2008) examined vertical displacement loops as alternate means of assessing typical work-energy potential.
The averaged Displacement loops (Fz-, Fx-, Velocity- and Power-Displacement loops) (Gollhofer et al., 1992; McBride et al., 2008) and the averaged Fz-Velocity loops were plotted to compare the total loop areas (Cormie et al., 2009; 2010; Gathercole et al., 2015).