Limited ankle dorsiflexion increases the risk for mid-portion Achilles tendinopathy in infantry recruits: a prospective cohort study.

Alon Rabin,Aharon S Finestone,Zvi Kozol

doi:10.1186/s13047-014-0048-3

Abstract

BackgroundAchilles tendinopathy (AT) is a prevalent condition among runners and military personnel. Although ankle dorsiflexion (DF) range of motion (ROM) as measured with the knee bent has not been previously associated with AT, the literature concerning its role is limited. In addition, the role of lower extremity movement pattern in the pathogenesis of AT has not been studied prospectively.The purpose of this study was to further explore the role of ankle DF ROM as measured with the knee bent and that of lower extremity movement pattern as risk factors for mid-portion AT.MethodsSeventy healthy male military recruits (mean ± SD age, height and body mass of 19.6 ± 1.0 years, 176.0 ± 10.0 cm, and 71.5 ± 7.4 kg) participated in this study. Ankle DF ROM as measured with the knee bent in weight-bearing (WB) and non-weight-bearing (NWB), as well as lower extremity quality of movement during a lateral step down (LSD) test were measured at baseline. Participants were then followed for a 6-month period of army basic training with recording of the development of AT.ResultsFive participants developed AT during training. Participants that developed AT had a more limited NWB ankle DF ROM (27.40 versus 21.10, p = 0.025). The quality of lower extremity movement did not differ between injured and uninjured participants (p = 0.361).ConclusionsA more limited ankle DF ROM as measured in NWB with the knee bent increases the risk of developing AT among military recruits taking part in intensive physical training.

Highlights

Achilles tendinopathy (AT) is a prevalent condition among runners and military personnel
The flexibility of the gastrocnemius has been previously associated with AT [10,11], the kinematics of running suggest it is the flexibility of the soleus that may be more relevant to the pathogenesis of this condition
The purpose of this study was to examine whether ankle DF as measured with the knee bent, as well as the quality of movement as measured by the lateral step down (LSD) can predict the development of AT in male military recruits undergoing army basic training (ABT)

Summary

Introduction

Achilles tendinopathy (AT) is a prevalent condition among runners and military personnel. The purpose of this study was to further explore the role of ankle DF ROM as measured with the knee bent and that of lower extremity movement pattern as risk factors for mid-portion AT. The simultaneous ankle DF and knee flexion that occur during the first half of the running cycle, are controlled eccentrically by the ankle plantarflexors and serve to absorb the impact of the upper body [12,14] This shock-absorbing mechanism is likely to strain the soleus more than the gastrocnemius as its origin on the tibia makes it suitable for controlling knee flexion under weight-bearing conditions. As it has been shown that a more limited flexibility of the gastrocnemius increases absorption work by the plantarflexors during walking [16], it is possible, that a more limited flexibility of the soleus would likewise increase absorption work by the plantarflexors during running, which may lead to increased strain on the Achilles tendon

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