## 5 Discussion
While our protocol was not designed with considerations of inducing strength adaptations, it can be speculated that as training progressed, performance improved and the tracking was made more challenging, this likely increased muscular demand and forearm muscle activation. Increases in muscular strength are typically observed after high intensity training and the resistance provided in the tracking task was a low percentage of the participant's maximum wrist strength. However, low loads at a high dosage can elicit strength gains. This has been demonstrated in work by [26], that low loads can promote increases in muscle growth especially for untrained participants. These gains may be both functionally and metabolically meaningful; it has been shown that resistance training in persons with MS is often attributed to neural adaptations rather than an increase in muscle mass [28]. It can be assumed that the strength gains observed in this study can be applied to improvements in motor control of the distal upper limb. Future studies should focus on this area of research, particularly with the use of quantitative assessment tools. Group averages in grip force endurance showed 60-78% increases from baseline to post intervention in the trained and control limb, respectively, indicating augmented muscular endurance post-intervention. There was a trend towards significance and a 60% increase in grip endurance is likely clinically significant and is a meaningful improvement that could translate to improved functionality in ADL. It is likely that our noted endurance changes may relate to improvements in ADLs, and this should be investigated further. The findings from this study suggested a correlation between wrist strength and hand motor control. Resistive training targeted both eccentric and concentric movements of the muscles of the forearm and significant correlations were found between wrist strength and tracking errors; as isometric wrist strength increased, tracking errors decreased. Interestingly, there was no correlation found between EDSS score and tracking error. A higher score on the EDSS is representative of an increase in severity/disability of disease. It could be expected that those with a greater level of disease would have poorer tracking performance. Tracking error could be linked to functional performance or ability to perform ADLs. This finding could suggest that EDSS is not an appropriate indicator of upper limb disability and additional quantitative measures should be taken by the clinician or the researcher when investigating the upper limb in MS. This poor correlation in our population suggests that further work is needed in this area, particularly in the development of objective robotic assessment tools for the upper limb to reduce reliance on subjective questionnaire assessments. Despite improvements in tracking error and wrist strength, this work also demonstrates that our progressive robotic rehabilitation program for this specific population may not promote the transfer of learned skills. In our work, it appears that this population benefits from task-specific or goal directed exercises, rejecting our original hypothesis. This is shown in grip force, ROM and 9-HPT. The PRWE was a questionnaire pertaining to how the participant was feeling based upon pain and daily functioning at home on a 0-10 scale. No significant group differences were observed. As the participants were to respond to the difficulty of performing a task on a scale of 1-10, the large rating scale may have been insensitive to capturing anecdotal responses. Participants in this study were not undergoing additional therapy for training programs and were mostly inactive; for a population such as this it is important to engage in any active rehabilitation programs to promote improvements in mental and physical well-being.