Table 1 Summary of feasibility outcome measures and thresholds
| Â | Measure | Threshold |
|---|---|---|
Demand | Recruitment rate | 6 participants per month |
Conversion rate |  ≥ 75% | |
Acceptability | MOS questionnaire |  ≥ 75% of the intervention group score more than 5/10 for each of questions 1–6 |
Adherence | ||
 Footwear/orthoses | Orthotimer® sensor 4-weekly diaries |  ≥ 75% of participants wear the footwear/orthoses for an average of ≥ 5 h per day |
 Exercise | PhysiTrack® app / diary |  ≥ 75% of participants complete at least 24/36 (66%) of the exercise sessions |
 Adverse events | four-weekly diaries |  < 15% and no serious events |
 Retention rate | Proportion of participants followed up at 12 weeks |  ≥ 80% retention |