Measures

Participants were assessed at baseline (pre-training, 0-weeks), post-training (4-weeks) and follow-up (12-weeks) in the Neurological Ageing and Balance Research Unit at the University of Queensland. Personal and stroke-related details were collected and the modified Rankin Scale performed to describe the severity of disability present at baseline. Adverse events were reported in the training log (e.g., fall, negative response to tRNS or OT-stim) during training, and the follow-up assessment book for post training events (e.g., fall). Training outcomes of sessions and repetitions completed were recorded in training logs.

All clinical measures were obtained at each timepoint. The primary clinical outcome measure was Motor Assessment Scale item 6 (Upper Arm Function, MAS6) [18]. Secondary outcome measures were MAS item 7 (hand activities) and item 8 (advanced hand activities), along with impairment measures of muscle strength of triceps brachii and extensor carpi radialis, resistance to passive movement (Modified Ashworth Scale) and spasticity (Tardieu Scale) of elbow and wrist flexion [19], and shoulder pain on passive external rotation (Ritchie Articular Index) [20]. In addition, upper limb participation was evaluated according to the Rating of Everyday Arm Use in the Community and Home (REACH) scale [21].

MRIs were acquired pre and post training at the Centre for Advanced Imaging at The University of Queensland on a Siemens Magnetron 3T Trio whole body scanner using a 32-channel encoding head coil. A high-resolution T1-weighted anatomical scan (0.45 x 0.45 x 0.9 mm voxel size) was collected to determine lesion location. A single high-angular resolution diffusion imaging (HARDI) scan was subsequently performed using a single shot echo-planar imaging (EPI) sequence (TR = 9000 ms, TE = 113 ms, FOV = 230 x 230 mm, 55 slices, voxel dimensions = 2.3 x 2.3 x 2.3 mm³). Diffusion weighting was applied across 85 independent non-collinear orientations (b = 3000 s/mm²), along with three un-weighted images (b = 0 s/mm²). Only pre-training MRIs were evaluated.

In depth, one-on-one interviews were completed with each stroke survivor and their main carer (in the case of aphasic participants) to encourage comfortable sharing of personal information and individual experiences, and to facilitate individualized probing. Interviews were arranged by the blinded assessor and conducted by a facilitator not involved in any aspect of the study, who was independent of the research institution and therapy services the participant had engaged in.

Four open-ended stimulus questions (Table 1) underpinned each interview. In these discussions, the term function was used to encapsulate the ICF domains of impairment, activity and participation. At the commencement of each discussion, the facilitator explained the interview purpose and then proceeded to ask each of the four key questions. There was no strict adherence to the style and type of questioning beyond these four questions, with probes used to explore or challenge emerging themes, personal experiences and ideas. All discussions were drawn to a close with the facilitator summarizing the main points raised. The participants were then provided with the opportunity to add or dispute what had been said or contribute any final thoughts.

Primary question(s) within each category of questing for in-depth interviews