Acute effects of different orthoses on lower extremity kinetics and kinematics during running; a musculoskeletal simulation analysis

Abstract

PURPOSE: The current investigation aimed to examine the effects of different orthotic conditions on the biomechanical mechanisms linked to the aetiology of chronic pathologies using musculoskeletal simulation. METHODS: 16 male and 20 females ran over an embedded force plate at 4.0 m/s, in five different conditions (medial, lateral, no-orthoses, semi-custom and off the shelf). Kinematics of the lower extremities were collected using an eight-camera motion capture system and lower extremity joint loading also explored using a musculoskeletal simulation approach. Differences between orthoses conditions were examined using 2 x 2 mixed ANOVA. RESULTS: External instantaneous load rate was significantly reduced in the off the shelf orthoses (male=1290.60 and female=1567.10N/kg/s) compared to the medial (male=1480.45 and female = 1767.05N/kg/s) and semi-custom (male=1552.99 and female=1704.37N/kg/s) conditions. In addition, peak patellofemoral stress was significantly lower in the off the shelf orthoses (male=68.55 and female=94.91KPa/kg) compared to the lateral condition (male=70.49 and female=103.22KPa/kg). Finally, peak eversion angles were significantly attenuated in the medial orthoses (male=-6.61 and female=-7.72deg) compared to the lateral (male=-9.61 and female=-10.32deg), no-orthoses (male=-8.22 and female=-10.10deg), semi-custom (male=-8.25 and female=-9.49deg) and off the shelf (male=-7.54 and female=-8.85deg) conditions. CONCLUSIONS: The current investigation shows that different orthotic devices/ configurations may provide distinct benefits in terms of their effectiveness in attenuating the biomechanical parameters linked to the aetiology of chronic running injuries.