Effectiveness of mechanical treatment with customized insole and minimalist flexible footwear for women with calcaneal spur: randomized controlled trial

BACKROUND: Calcaneal spurs are described as bony outgrowths arising on medial calcaneal, where inappropriate footwear can promote disease progression. OBJECTIVE: Investigate the effectiveness of mechanical treatment with customized insole and minimalist flexible footwear during gait training program in women with calcaneal spur. METHODS: Design: A single-blinded, randomized and controlled trial. Setting: Biomechanics laboratory. Participants: Forty-three women, 29 with calcaneal spur and 14 control. INTERVENTION: Gait training program with use of the minimalist flexible footwear (MFG n = 15, age: 48.9 ± 9.4, height: 1.61 ± 0.1, BMI: 32.1 ± 7.0) and customized insole on footwear (COIG n = 14, age: 50.3 ± 5.8, height: 1.62 ± 0.1, BMI: 32.2 ± 4.3) and control (CG n = 14, age: 47.8 ± 8.6, height: 1.63 ± 0.1, BMI: 27.5 ± 4.5), followed of the evaluations: baseline (T0) and after three (T3) and six (T6) months. Duration of the intervention was of the six months consecutive for at least 42 h per week (six hours a day, seven days a week). Outcome primary were calcaneus pain (visual analogue scale), Foot Function Index (FFI), Foot Health Status Questionnaire (FHSQ-Br) and 6-min walk test (6MWT). Secondary was plantar pressure distribution by a pressure platform system during gait and static index foot posture (FPI). Statistical analysis: analysis of variance for repeated measure and between groups were used to detect treatment-time interactions (α = 5%). Effect size with D Cohen’s also was used between T0 and after six (T6) months of intervention. RESULTS: The MFG and COIG were effective at reducing pain after six months (MFG: 2.5–4.5 CI, p = 0.001; COIG: 1.5–3.5 CI, p = 0.011). The FFI and FHSQ-Br showed improvements with MFG and COIG after T6 (MFG: 13.7–15.4 CI, p = 0.010; COIG: 11.3–15.0 CI, p = 0.001). The 6MWT increased with MFG (589.3–622.7 CI) and COIG (401.3–644.7 CI) and foot pronation was decreased after T3 and T6 MFG (FPI Right: 4.2–5.4 CI; Left: 3.6–5.4 CI) COIG (FPI Right: 3.4–6.8 CI; Left: 3.3–5.7 CI). The contact area reduced on forefoot and rearfoot with MFG and GOIG and midfoot and rearfoot with MFG. Maximum force was reduced on foot with MFG after T3 and T6. The peak pressure was reduced on the forefoot with MFG and COIG and on midfoot and rearfoot with MFG. CONCLUSIONS: The mechanical treatment with customized insole and minimalist flexible footwear during gait training program during six months in women with calcaneal spur reduced the calcaneus pain, increased function and health feet and reduced plantar load on the rearfoot, midfoot and forefoot. However, the footwear alone was more effective than when combined customized insole, given the greater efficacy on clinical and biomechanical aspects. TRIAL REGISTRATION: ClinicalTrials.gov NCT03040557 (date of first registration: 02/02/2017).