Lower limb neuromotor control during perturbed and unperturbed gait conditions in male runners with Achilles tendinopathy: an exploratory analysis

TL;DR

This study explores how runners with Achilles tendinopathy control their leg muscles during walking and running, finding differences compared to healthy runners.

Contribution

The study identifies neuromotor control differences in Achilles tendinopathy during walking and running tasks using perturbed and unperturbed conditions.

Findings

During walking, Achilles tendinopathy runners showed delayed muscle onset in tibialis anterior, peroneus longus, and vastus medialis.

During running, Achilles tendinopathy runners had longer gastrocnemius medialis activity and delayed gluteus maximus onset.

Perturbed walking revealed delayed tibialis anterior reflex latency in Achilles tendinopathy runners.

Abstract

Achilles tendinopathy (AT) is common among runners and typically presents with Achilles tendon pain. Neuromotor alterations have been reported in AT during demanding tasks such as running; however, alterations during functional tasks such as walking remain poorly understood. Such information may be relevant and inform rehabilitation targets. Therefore, this exploratory study investigated lower limb neuromotor control during walking and running in people with AT compared with healthy controls (CO). Twenty-four male runners participated (AT = 12, CO = 12) and completed walking (WALK), perturbed walking (PERTWALK), running (RUN), and perturbed running (PERTRUN) on a custom split-belt treadmill. Lower limb muscle activity was recorded using electromyography to assess activity onset, offset, and duration during unperturbed tasks, and reflex latency and amplitude during perturbed tasks. A MANOVA (α = 0.05) examined group effects (AT/CO). During WALK, AT showed delayed onset of tibialis anterior, peroneus longus, and vastus medialis (p < 0.05). During RUN, gastrocnemius medialis duration was longer, while gluteus maximus onset was delayed and shorter in AT (p < 0.05). During PERTWALK, tibialis anterior reflex latency was delayed in AT (p < 0.05), whereas reflex amplitudes and all PERTRUN outcomes were not significant. These findings indicate potential neuromotor differences in AT.

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