Descriptive Characteristics And Running Biomechanics Of Male Distance Runners With Previous Running Related Injury

PURPOSE: Running shoe companies have designed footwear tailored to foot type, providing comfort and/or stability through reduction of forefoot and rearfoot impact forces and control of rearfoot motion during running. However, it is unclear whether footwear creates the adjustments intended for the foot type even when runners have experienced a previous running related injury. Thus, the purpose of this study was to describe footwear selection, foot type, and running biomechanics in previously injured male distance runners to explore similarities and patterns using a case series approach. METHODS: Six participants completed this case series. Cases 1 and 3 were recreational runners, Cases 2, 4, and 5 were professional athletes, and Case 6was a coach for a professional sport team. All participants had a history of lower extremity running related injury within the last year, but no current injury. A questionnaire on shoe selection and injury history, the Foot Posture Index-6, dorsiflexion range of motion (DFROM) using the Weight Bearing Lunge Test and running trials in a biomechanics lab were completed.Max vertical, anteroposterior, and mediolateral ground reaction force (GRF) per limb were recorded as N/kg. Frontal and sagittal plane kinematics of the ankle were calculated for initial contact (IC), absorption, propulsion, and toe-off. Vertical and anteroposterior GRF were used with a 10 N threshold to determine these phases. Cases were compared to identify similarities orpatterns associated with injury history, shoe selection process, foot characteristics, habitual footwear, and kinematics and kinetics. RESULTS: Cases 3 and 4 with previous Achilles/shank injuries had a DFROM asymmetry >2 cm with reduced DFROM in the affected limb. Case 4 sought care after injury and Case 3 did not. Case 3 was the only highly pronated foot type and using footwear not recommended for overpronation. Case 3 was plantarflexed at IC, lacked dorsiflexion at absorption, lacked foot progression into eversion, and had the highest vertical GRF compared to all other cases. Despite the asymmetry, Case 4 had close to normative DFROM and typical foot progression. CONCLUSIONS: Injury history may affect long-term DFROM if not rectified. Reduced DFROM coupled with overpronation and incorrect footwear may influence running biomechanics.