874 MEP173 – Biomechanical effect of posterior heel lifts orthosis on Achilles tendon in athletes

AbstractBackground Overwork, with a lack of recovery periods, is the main consequence of Achilles tendinopathy (AT)(Thomopoulos, 2015). In podiatry, the literature suggests that treatment should be based on relaxation of the triceps surae (TU, 2018). For this purpose, heel lifts have been recommended: a shoe-insert designed to place the ankle in a more plantar position, reducing Achilles tendon loading (ATL)(Schepsis, 2002).Objective Verified, biomechanically, the heel lifts effect on reducing the ATL in order to prevent tendinopathy.Design On a force platform (AMTI), participants were asked to perform 20 single leg landings at 30 cm from the ground. Motion Analysis was used to determine lower limb trajectory. ATL was determined by dividing the plantarflexion moment (MPF) by the estimated AT moment arm (MA). The MA was quantified as a function of the ankle sagittal plane angle (SAK). ATL was normalized to bodyweight (B.W). The mathematical model used was: ATL=MPF/MA with MA=1⁄4−0,591+0,08297*SAK-0,0002606*SAK2 (Sinclair, 2014).Setting Healthy sportsmen and womenParticipants 15 participants (11 men; 4 women, 26.8±2.8 years; 173.5±8.3 cm; 70.5±8.4 kg) practising a sport involving lower limbs, for at least three training sessions per week, no history of lower limbs and not wearing orthopedic insoles, were included.Intervention 10 single leg landings were performed with posterior heel lift (HL; EVA, 8mm, 35° shore A) and another 10 single leg landings without heel lift (NOHL).Main Outcome Measurements Dependant variable is ATL.Results ATL mean values (±SD) were 4.63±0.8 B.W and 3.93±4.9 B.W for NOHL and HL, respectively. Student t test showed a significant higher ATL values for NOHL than HL (p<0.001). Anova analysis (Statistica v14.0.1) did not show age, gender, nor IMC effect (P>0.05).Conclusions Posterior heel lifts, could be an interesting and inexpensive way to reduce ATL, promoting a reduction in lesions during practice and/or better recovery outside.