title: Shock-absorbing effect of shoe insert materials commonly used in management of lower extremity disorders.
abstract: The efficacy of 3 shock-absorbing materials was compared by determining impact characteristics with a drop test method and also by testing the effect of each material when used as a shoe insert in 16 asymptomatic subjects. Peak vertical ground reaction force (F1, F2, F3) and temporal force factors (T1, T2, T3) were obtained with a force plate at a high-frequency sampling rate. Impact force, impact time, impact slope, and impact energy were determined. A standard weight was dropped from 3 heights on each material covering the force plate while reduction of peak force was compared. Impact force was attenuated most effectively by Insert 3 (polymeric foam rubber) and averaged 11% less than that in shoes without inserts. Impact time was increased for all 3 inserts. Impact slope and impact energy were reduced significantly in Insert 3. There was a significant difference in peak vertical force F1 for all 3 inserts, in vertical force F2 for Insert 2 (viscoelastic polymeric material), and in vertical force F3 for Insert 2. Drop-test studies showed that at all ball heights, the highest mean peak force was observed consistently in Insert 2.
authors.affiliation: Biomechanics Laboratory, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: N
authors.initials: N
authors.lastname: Shiba
authors.forename: H B
authors.initials: HB
authors.lastname: Kitaoka
authors.forename: T D
authors.initials: TD
authors.lastname: Cahalan
authors.forename: E Y
authors.initials: EY
authors.lastname: Chao
mesh_terms: D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait; D006801:Humans; D007869:Leg Injuries / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D009989:Orthotic Devices; D011108:Polymers; D012408:Rubber; D012775:Shoes
chemical_list: D011108:Polymers; D012408:Rubber