AbstractsBiology & Animal Science

Evaluating stiffness of the lower limb ‘springs’ as a multifactorial measure of achilles tendon injury risk in triathletes

by Anna V Lorimer

Institution: AUT University
Year: 0
Keywords: Achilles injury; Triathlon; Joint stiffness; Running
Record ID: 1298182
Full text PDF: http://hdl.handle.net/10292/7990


Achilles tendon injuries were identified as problematic for New Zealand High Performance athletes by Triathlon New Zealand. Analysis of six years of injury data for New Zealand high performance triathletes indicated that Achilles tendon injuries (17%) were among the most common overuse lower limb injuries together with calf injuries (17%). The majority of injuries were attributed to running. These results correspond to injury analysis of British elite triathletes with reported high prevalence of Achilles tendon injuries in Olympic distance athletes. The exact mechanism of injury and what causes the pain is still unclear. However the reoccurring nature of the injury and often prolonged recovery times signal a need for the development of preventative interventions. The main aim of the thesis was to determine whether a single measure can be used to identify individuals at risk of Achilles tendon injury. This was achieved through a series of specific questions which followed the Van Mechelen and Finch models for injury prevention research. The thesis was able to address, the extent of the problem, what is understood about the problem and make a unique contribution to understanding the mechanism of injury. Individual risk factor analysis for Achilles tendon injuries via a systematic literature review resulted in only five risk factors that were clearly associated with injury. Increased braking force was associated with increased injury risk, while increasing surface stiffness, high arch height, large propulsive force and large vertical force were associated with decreased injury risk. Various other risk factors were also found that did not show clear effects. The slow progressive nature of overuse injuries suggests that the changes in loading to the tendon are subtle and therefore, individual risk factor analysis is not likely to clearly determine the causative factors. Therefore, investigation of measurements that measure changes in movement patterns may provide greater insight. Stiffness was found to be increased in the leg and decreased in the ankle for athletes who had prior Achilles tendon injuries compared to uninjured controls. Lower limb stiffness is a measure of how the joints work in relation to one another to absorb impact upon contact and reflect the synergistic activity of muscles, tendons and ligaments. Stiffness therefore may provide a useful measure of looking at the landing movement as a whole and provide information regarding injury risk. The influence of the different risk factors, that were identified to have a definite or possible role in Achilles tendon injury risk, on lower limb stiffness were therefore investigated via a systematic review. The majority of Achilles injury risk factors were associated with increases in lower limb stiffness measures, however the results were unclear. Based on the evidence, it was considered that stiffness was a potentially useful measure for analysing Achilles tendon injury risk and should be investigated further. In a reliability laboratory study of 12…