PhD Defence by René Korsgaard Brund
René Korsgaard Brund will defend his PhD thesis: "The Runtech Study - Risk Factors and their Association(S) in Relation to Overuse Injuries in Recreational Male Runners"
26.10.2018 kl. 13.00 - 17.00
Running is associated with injuries, mainly overuse injuries, and a great proportion of active runners sustain one or more overuse injury yearly. A multitude of biomechanical factors have been proposed to elicit running-related overuse injuries. However, these factors or combinations of factors that are leading to the most frequent running-related overuse injuries, are inconclusive. Therefore further evidence is needed to clarify the etiology of running-related overuse inju-ries. The purpose of this PhD thesis is to provide further insight into the etiology leading to the most frequent running-related overuse injuries and to investigate potential relationships between risk factors associated with running-related overuse injuries. Three specific research questions were asked to pursue the purpose:
Research question 1: Is eccentric hip abduction strength associated with specific hip and knee joint kinematic patterns, which again may be related to knee injury?
Research question 2: Is medial shoe-ground pressure associated with the development of Achilles tendinopathy, plantar fasciitis and/or medial tibial stress syndrome (APM injuries) among recreational male runners?
Research question 3: How does the injury incidence rate ratio (IIRR) change over a one year prospective study involv-ing two changes of running shoes?
A group of 99 recreational male runners were monitored with respect to running activity and running injury for one year. At baseline, runners were provided with a pair of neutral running shoes, in which they should run the first 500km. Eccentric hip abduction strength, shoe-ground pressure profiles and kinematics during running were measured before (baseline) and approximately after the first 500km of running in the provided pair of neutral running shoes. In case of a running-related overuse injury, the injury was clinically examined, diagnosed and recommendations concerning re-covery strategies were given.
The answer to research question 1 provided further insights into identifying a subgroup of runners displaying an asso-ciation between eccentric hip abduction strength and hip and knee kinematics. Overall, no associations between eccen-tric hip abduction strength and hip and knee kinematics were found in the main group. In a subgroup demonstrating simultaneous hip adduction and knee abduction (valgus) during the first half of the stance phase, an association between eccentric hip abduction strength and the magnitude of the knee abduction angular excursion was demonstrated.
The answer to research question 2 provided evidence to the effect shoe-ground pressure distributions has on the risk of APM-injuries. The group of runners with higher medial shoe-ground pressure during running sustained a greater pro-portion of APM-injuries. It is not certain if all three types of injuries (Achilles tendinopathy, plantar fasciitis and medial tibial stress syndrome) are associated with higher medial shoe-ground pressure. Since only rather few APM-injuries in total occurred during the period of observation this uncertainty could not be addressed with the present data set. The exact associations between higher medial shoe-ground pressure and each of the specific injuries need further clarifica-tion.
The answer to research question 3 can be viewed as a first step to shed light on the association between changing running shoes and running injury incidence rate. Running-related overuse injury incidence rate ratio (IIRR) was in-creased above one around the changes of running shoes and below one in the intermediate periods. However, it was not possible to confirm that the increased IIRRs were caused by the running shoe changes per se. Additionally, it could not be excluded that differences in weekly running distance had an influence on the results, together with other uni-dentified risk factors. Large scale studies involving alternative experimental protocols are needed to provide further insight into the association between running-related overuse injury incidence rate and running shoe changes.
Fredrik Bajers Vej 7A4, room A4-106