Intrinsic gait-related risk factors for Achilles tendinopathy in novice runners: a prospective study.

The purpose of this prospective cohort study was to identify dynamic gait-related risk factors for Achilles tendinopathy (AT) in a population of novice runners. Prior to a 10-week running program, force distribution patterns underneath the feet of 129 subjects were registered using a footscan pressure plate while the subjects jogged barefoot at a comfortable self-selected pace. Throughout the program 10 subjects sustained Achilles tendinopathy of which three reported bilateral complaints. Sixty-six subjects were excluded from the statistical analysis. Therefore the statistical analysis was performed on the remaining sample of 63 subjects. Logistic regression analysis revealed a significant decrease in the total posterior-anterior displacement of the Centre Of Force (COF) (P=0.015) and a laterally directed force distribution underneath the forefoot at 'forefoot flat' (P=0.016) as intrinsic gait-related risk factors for Achilles tendinopathy in novice runners. These results suggest that, in contrast to the frequently described functional hyperpronation following a more inverted touchdown, a lateral foot roll-over following heel strike and diminished forward force transfer underneath the foot should be considered in the prevention of Achilles tendinopathy.