BIOMECHANICS AS AN INTERDISCIPLINE - Biomechanics and Motor Control of Human Movement - page 7

Figure 1.5 Example of a ground reaction force curve that has sometimes been used
in the diagnostic assessment of pathological gait.

new information from the analysis. The information can also cause a neg-
ative decision, for example, to cancel a planned surgical procedure and to
prescribe therapy instead.
Some biomechanical assessments involve a look at the description itself
rather than some analyzed version of it. Commonly, ground reaction force
curves from a force plate are examined. This electromechanical device gives
an electrical signal that is proportional to the weight (force) of the body acting
downward on it. Such patterns appear in Figure 1.5. A trained observed can
detect pattern changes as a result of pathological gait and may come to some
conclusions as to whether the patient is improving, but he or she will not
be able to assess why. At best, this approach is speculative and yields little
information regarding the underlying cause of the observed patterns.

1.2 BIOMECHANICS AND ITS RELATIONSHIP
WITH PHYSIOLOGY AND ANATOMY

Because biomechanics is a recent entry on the research scene, it is important
to identify its interaction with other areas of movement science: neurophysi-
ology, exercise physiology, and anatomy. The neuromuscular system acts to
control the release of metabolic energy for the purpose of generating con-
trolled patterns of tension at the tendon. That tension waveform is a function
of the physiological characteristics of the muscle (i.e., fiber type) and of its
metabolic state (rested vs. fatigued). The tendon tension is generated in the
presence of passive anatomical structures (ligaments, articulating surfaces,
and skeletal structures). Figure 1.6 depicts the relationship between the sen-
sory system, the neurological pathways, the muscles, the skeletal system, and
the link-segment model that we analyze. The essential characteristic of this
total system is that it is converging in nature. The structure of the neural
system has many excitatory and inhibitory synaptic junctions, all summing
their control on a final synaptic junction in the spinal cord to control indi-
vidual motor units. The α motoneuron , which is often described as the