Biomedical Engineering Reference
In-Depth Information
FIGURE 10-13
Otto Bock split
hook. (Courtesy of
Otto Bock, with
permission.)
FIGURE 10-14
Mechanical hand
showing the
finger-control
mechanism.
(Courtesy of Otto
Bock, with
permission.)
Otto Bock hand shown in Figure 10-14. As with the split hook, the fingers of this prosthesis
are controlled by a cable actuation driven by a harness.
Hybrid prostheses fall between passive and active types insofar as they use a cable-
operated elbow and an electrically controlled terminal device. The advantage of this format
is that the control strap can be less restrictive as it controls only elbow flexion (Muzumdar,
2004).
10.8.2 Walking Dynamics Using a Passive Prosthesis
A transfibial amputation has a major effect on joint motion and muscle activity during
the different stages of the gait cycle. Prosthetics attempt to restore as much synergy as
possible using advanced materials and mechanics, but there are still some difficult problems
(Pons, 2008):
