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Chapter 5 – Discussion
steadiness and strength than the dominant hand (Adam, de Luca, &
Erim, 1998). The less favoured hand has also been shown to exhibit
greater tremor amplitudes when compared to the dominant hand
(Bilodeau, Bisson, DeGrace, Despres, & Johnson, 2009). This may suggest
that the most affected hand has a greater scope for improvement with
RT.
Neither bimanual PPT tasks showed any significant improvement in the
present study. While such a result was initially a little surprising when
compared to that of the unilateral PPT tasks, it would appear somewhat
consistent with the principle of specificity. This principle the greatest
change in performance occurs in tasks similar to that done in training.
As training only involved unilateral dumbbell RT exercises, the significant
improvements in unilateral PPT performance and lack of change in the
two bilateral PPT tasks appears plausible. The non-significant change for
bimanual dexterity tasks may reflect the complex CNS relationship
between changes in function brought on by RT and performance in
visuomotor tasks such as the PPT. Adding further complexity to the
issue, some aspects of cortical and sub-cortical processing also differ
depending on whether unilateral or bilateral coordination tasks are
being performed (van den Berg, Swinnen, & Wenderoth, 2011). Our
findings reinforce the concept of specific task-related changes to RT, and
supports the task-related alterations in the control of movement evident
in a previous ET RT training study (Bilodeau, et al., 2000). Therefore,
training programs which include task-specific activities, such as
unilateral and bilateral strength and coordination movements, may
further improve functionality in ET patients.
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