Neuromotor control of gluteal muscles in runners with AT
Hip kinematics are closely linked to foot kinematics via mechanical links and may be associated with increased foot eversion. Several studies have reported increased foot eversion during running in patients with Achilles tendinopathy (AT). Thus, the aim of the study is to compare the activation of the gluteus medius (GMED) and maximus (GMAX) – two muscles that alter hip kinematics – in runners with AT.
The results of the study demonstrate altered neuromuscular control of the GMED and GMED in runners with AT. During running, GMED typically activates before heel strike so as to stabilize the hip and the pelvis. In runners with AT, GMED is activated with a delay, which consequently might affect the kinematics of knee and ankle resulting in rear foot inversion. Similarly, GMAX is activated with a delay and for a shorter duration in runners with AT. GMAX is the primary hip extensor and via a kinetic chain, a decreased hip extension moment might be compensated by an increased ankle plantarflexion moment which could potentially increase the load on the Achilles tendon.
Despite their coexistence, it is still not clear whether these alterations are predisposing factors of AT, a consequence of it or maybe a combination. Therefore, they should be treated carefully.
> From: Franettovich Smith et al., Med Sci Sports Exerc 46 (2014) 594-599. All rights reserved to American College of Sports Medicine. Click here for the Pubmed summary.