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282 Control theory in biomedical engineering

As shown in Figs. 5 and 7, by adding velocity control to the model, tran-
sient time of stride duration increased and velocity decreased. Also, the SD
value for the stride time of c_TLV was much more than that of c_TL. It
was shown that the more the specific parameter receives control, the more
SD value the other one gets. These results might be consistent with the con-
cept of the uncontrolled manifold hypothesis (Scholz and Sch€oner, 1999;
Monaco et al., 2018). More research is suggested to investigate this hypothesis.

5 Conclusion

This chapter presented a simple bio-mechanic model for human walking on
the treadmill. This study showed that in addition to velocity and position
control, control of stride length and time is also necessary to keep walking
at its optimal mode. Moreover, it was also shown that this framework of
modeling has the capability to explain differences between α (DFA) in time
series of stride velocity of walking overground and on a treadmill. Further
research is required to explore the relationship between α (DFA) of stride
length, time, velocity, and position as well as propose controllers in different
motor and mental tasks.

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