Feasibility of Force-Sensing Insoles for Measuring Lower Limb Loading in Older Adults with Obesity

Research Objectives To determine the feasibility of using force-sensing insoles to measure lower limb loading in older adults living with obesity enrolled in a clinical weight loss program. Design Ancillary study to the Incorporating Nutrition, Vests, Education and Strength Training (INVEST) randomized controlled trial. Bilateral lower limb loading was measured using force-sensing insoles (Loadsol, Novel) at baseline and 6-month follow up while participants walked for 2-minutes at their usual speed for three trials. At follow-up, participants completed a satisfaction survey. Limb loading outcomes included peak force, loading rate, total cumulative force, and step time. Setting Wake Forest University research laboratory. Participants 44 overweight or obese participants [age: 67 (5.1) years; sex: 11 males; BMI: 33.7 (3.1) kg/m2] 60-85 years old completed baseline testing. Thirty-seven completed follow-up. Interventions Intentional weight loss (WL) plus weighted vest wear, WL plus resistance training, or WL alone. Assessors were blinded to participant groups. Main Outcome Measures Feasibility was defined as: 1) ≥80% usable data at baseline and follow-up visits; 2) ≥80% satisfaction from participant surveys; and 3) ≤15 minutes to collect and analyze data per participant. Results All limb loading data was found to be usable. At baseline across all participants, average (standard deviation) peak force was 1.07 (0.04) N/kg, loading rate was 0.07 (0.02) N/s/kg, total cumulative force was 17.5 kN*s/kg, and step time was 0.74 (0.04) secs. At follow up, peak force was 1.12 (0.04) N/kg, loading rate was 0.08 (0.02) N/s/kg, total cumulative force was 17.2 kN*s/kg, and step time was 0.71 (0.05) secs. Average satisfaction was 80% (6.3%). All data collection was completed in under 10 minutes, and data analysis was completed in under 5 minutes per participant. Conclusions Force-sensing insoles appear to be feasible to measure limb loading in the lab within a clinical research trial. Author(s) Disclosures This work was supported by the National Institute on Aging (Grant No. R01 AG059186 & P30 AG021332). Jason Pharmaceuticals, a wholly owned subsidiary of Medifast, Inc. made an in-kind product donation for the meal replacements used in this study.