Tactile Incentiviser Improves Partial Weight Bearing After Lower-Limb Surgery

Background: After lower-limb surgery, many patients are instructed to walk with only a fraction of their body weight on the operated leg (partial weight bearing). Traditional teaching methods-verbal instructions or brief practice with a bathroom scale-often fail to maintain the load within a safe range, potentially increasing the risk of delayed bone healing or implant failure. Purpose: This pilot study investigates whether a very low-cost, purely mechanical "tactile incentiviser" placed inside the shoe can assist participants in adhering to a 20% body-weight limit during the first two weeks of inpatient rehabilitation. Design: Single-centre, parallel-group, randomised controlled trial. Thirty-four adults undergoing hip or knee arthroplasty, or surgery for femoral-shaft or pelvic fracture, were enrolled. Randomisation was performed using a computer-generated list in sealed envelopes. Outcome assessors were blinded. Intervention: The device consists of four spring buttons embedded in a rubber insole that collapse and deliver a tactile cue when the 20% ± 1% load threshold is exceeded. Participants in the intervention group wore the insole during supervised walking sessions. Control participants received standard physiotherapy without feedback devices. Primary Outcome: Absolute deviation (kg) between prescribed and actual load, assessed with a pressure sensor at baseline and discharge. Secondary Outcomes: Pain intensity (NRS), Six-Minute Walk Test (6MWT) distance, and usability (System Usability Scale, SUS). Note: No results or conclusions are included here. Results will be reported in the appropriate Results Section after the study is completed.