My dissertation focuses on human motor learning and adaptation and centers on two questions: 1) Is an online platform conducive for conducting motor adaptation experiments? and 2) How successfully can human learning drive performance in a complex human-robot collaboration task? For the first question, we developed a web-based experimental platform to facilitate online data collection for motor learning studies. An online platform has several benefits including eliminating the need for expensive and finely calibrated hardware, reducing the time-intensive demand for on-site researchers, and allowing for the testing of a representative human population. However, there is a vital need to understand general feasibility and the considerations necessary to shift closely controlled human-subject experiments to an online setting. We conducted a validation study and a case study examining remotely collected data quality for an 80-minute experiment. We were able to replicate known motor learning phenomena and highlighted several specific challenges associated with online data collection. Most notably, we found that experiment durations > 60 minutes were susceptible to fatigue and compliance issues as there was a significant effect of time (trial number) on our results. However, we believe that targeted future development and careful execution will enable motor learning research to take advantage of online experimental capabilities. For the second question, we examined human performance in a human-robot collaboration task. The field is currently lacking in research on the human contribution to human-robot collaborations. Therefore, we developed a complex "trimanual" or 3-limb task where the human was solely responsible for driving performance. In addition to the two biological arms, a third robotic arm was controlled through electromyography (EMG) or muscle electrical signals. We evaluated task and coordination performance, providing a systematic evaluation of the differences between two muscle sites selected for EMG, the leg (tibialis anterior) and the head (temporalis muscle). Results demonstrated that subjects were able to show statistically significant improvement over all three primary metrics with a tolerable workload that was trending towards satisfactory by the conclusion of the experiment. Results also showed that ipsilateral limb coordination may be a limiter in three-limb coordination. Importantly, there was no statistical difference based on muscle site indicating promise for a variety of potential applications.