Altered neuromotor control of the Gluteus Medius and Gluteus Maximus in male runners with Achilles Tendinopathy

Abstract

Introduction: Achilles Tendinopathy is a prevalent musculoskeletal condition in running based sports. Whilst the etiology of the disorder is not yet fully understood, alterations in the neuromotor control of the gluteal muscles have been proposed to be associated with the condition. The purpose of this study was to compare the neuromotor control of the Gluteus Medius (GMED) and Gluteus Maximus (GMAX) muscles in runners with Achilles Tendinopathy to that of asymptomatic controls. Methods: Data were collected from two groups of male distance runners: an Achilles Tendinopathy group (AT; N = 14) and an asymptomatic control group (CRTL; N = 17). Electromyography (EMG) activity was recorded using surface electrodes during over-ground straight-line running. Results: The AT group demonstrated a delay in the activation of the GMED relative to heel strike (p = < 0.001) and a shorter duration of activation (p = < 0.001) compared to that of the CTRL group. However, GMED offset time relative to heel strike was not different between the groups (p = 0.063). The GMAX followed the trend shown by the GMED with the AT group demonstrating a delay in its activation (p = 0.008), and a shorter duration of activation (p = 0.002), compared to the CTRL Group. Unlike GMED, the GMAX exhibited a statistically significant earlier offset after heel strike (p = 0.001) in the AT group compared to the CTRL Group. Discussion: This study provides preliminary evidence to support the possible role of proximal neuromotor control of the hip muscles in AT.