Achilles Tendon Stiffness of Division 1 Track and Field Athletes

Background: No previous research provides data on Achilles tendon (AT) stiffness of Division 1 (D1) track and field (TF) athletes. Limited information is known on what variables influence tendon stiffness in athletes. AT stiffness may have an impact on injury and performance in D1 TF athletes, warranting research. The purpose of this study is to identify if there are factors that correlate with AT stiffness among D1 TF athletes. Methods: Fifty-one D1 TF athletes voluntarily participated in a cross-sectional study of AT biomechanical measurements at the beginning of the fall season. The MyotonPro was used for measurements at the midline of the AT between the medial and lateral malleoli. The average of 6 measurements, 3 per tendon, were used to calculate the mean AT stiffness of each athlete. Results: The mean AT stiffness was 704 N/m (95%CI 688.3, 718.9). There was significantly lower AT stiffness of D1 females 686 N/m (95% CI 639.4, 732.6) compared to males 745 N/m (95% CI 696.7, 792.9). When stratified according to sex, there was a negative correlation with height and AT stiffness in the male grouping (p=0.045) and increased stiffness in previously injured males 767 N/m (95% CI 721.2, 813.9) compared to healthy males 710 N/m (95% CI 684.2, 737). Discussion: Results from this study showed increased stiffness in males compared to females and male athletes with previous injuries. Continued research into factors that influence tendon properties is important to optimize tendon training with stiffness for sport performance and injury prevention in mind