Prospective analysis of intrinsic and extrinsic risk factors on the development of Achilles tendon pain in runners

Abstract

There are currently no generally accepted, consistent results that clearly characterize factors causing Achilles tendon pain (AT) in runners. Therefore, we carried out a prospective study to evaluate the multifactorial influence of clinical, biomechanical (isometric strength measurements and three-dimensional kinematics) and training-related risk factors on the development of AT. Two hundred sixty-nine uninjured runners were recruited and underwent an initial examination. One hundred forty-two subjects completed their participation by submitting training information on a weekly basis over a maximal period of 1 year. Forty-five subjects developed an overuse injury, with 10 runners suffering from AT. In an uninjured state, AT runners already demonstrated decreased knee flexor strength and abnormal lower leg kinematics (sagittal knee and ankle joint) compared with a matched control group. A relationship between years of running experience or previous overuse injuries and the development of new symptoms could not be established. The interrelationship of biomechanical and training-specific variables on the generation of AT is evident. A combination of alterations in lower leg kinematics and higher impacts caused by fast training sessions might lead to excessive stress on the Achilles tendon during weight bearing and thus to AT in recreational runners. © 2013 John Wiley & Sons A/S.