The authors have declared that no competing interests exist.
Eversion ankle sprains, although less common than inversion injuries, are often associated with greater severity and more complex recovery patterns. Their biomechanical origin remains less clearly understood.
To propose a functional, longitudinal kinetic chain model in which anterior innominate rotation (AS) may contribute to the development of eversion ankle sprain injuries.
This hypothesis-driven model is based on clinical observation and biomechanical reasoning. Anterior innominate rotation may lead to pelvic asymmetry, a functional long-leg pattern, internal femoral rotation, and toe-in mechanics.
These adaptations may increase medial loading, promote collapse of the medial longitudinal arch, and alter ground reaction forces. This may compromise medial stability and reduce the capacity to control eversion forces, increasing susceptibility to injury.
Eversion ankle sprains may represent the distal expression of proximal biomechanical dysfunction. Recognition of anterior innominate rotation may improve injury prevention strategies.
Eversion ankle sprains, although less common than inversion injuries, are often associated with greater severity and more complex recovery patterns. Despite their clinical significance, their biomechanical origin remains less clearly understood. This paper expands upon the previously proposed proximal-to-distal kinetic chain framework addressing inversion ankle sprain mechanisms in athletes described by Quintero (2026).
Traditional approaches emphasize local joint factors; however, increasing evidence supports the role of proximal biomechanics in influencing distal joint function. Alterations in hip mechanics, lumbopelvic stability, and lower limb alignment have been shown to affect movement patterns and injury risk
Anterior innominate rotation may represent an underexplored factor within this framework. This condition may lead to a functional long-leg presentation, internal femoral rotation, toe-in mechanics, and increased medial loading, potentially influencing distal joint behavior
Anterior innominate rotation may develop within the sacroiliac joint following trauma such as a fall onto the posterior superior ischial spine, posterior iliac crest, or anterior knee with extended leg, where force is transmitted proximally toward the pelvis. The pubic symphysis may function as a stabilizing anterior reference point during rotational displacement of the innominate.
Posterior innominate rotation may also develop following traumatic impact to the anterior aspect of the pelvis, where force transmission through the pelvic ring may induce rotational displacement at the sacroiliac joint. This mechanism may contribute to functional short-leg patterns, external femoral rotation, and toe-out mechanics associated with inversion ankle sprain susceptibility.
Anterior rotation may create pelvic asymmetry and a functional long-leg pattern, altering load distribution across the lower extremities.
Pelvic asymmetry may be associated with internal femoral rotation, contributing to toe-in gait patterns and altered alignment during dynamic activities.
Medial loading and pronation may be associated with dynamic knee valgus, representing a continuation of the proximal-to-distal kinetic chain
Alterations in fibular positioning and rearfoot mechanics may influence ankle stability and load transmission, affecting the ability to control eversion forces
These adaptations may increase medial loading and contribute to collapse of the medial longitudinal arch, particularly under repetitive stress
The combined effect of these biomechanical adaptations may increase susceptibility to eversion loading, particularly during dynamic athletic movements.
· Pelvic asymmetry
· Toe-in gait
· Medial loading patterns
· Arch collapse
· Knee valgus
· Asymmetrical footwear deformation
These conditions may coexist and present with overlapping symptoms. Iliopsoas dysfunction may involve deeper anterior hip pain and functional limitations, whereas anterior innominate rotation is more consistently associated with observable biomechanical patterns along the kinetic chain.
· Functional: unilateral, asymmetrical, dynamic
· Structural: bilateral, stable, hereditary
This paper proposes a longitudinal kinetic chain model linking anterior innominate rotation to eversion ankle sprain risk. The model extends existing knowledge on proximal influences in injury mechanisms.
The condition may coexist with other dysfunctions and may present with non-classical symptom distributions. It should be interpreted within a functional context.
Even though focused on athletes, similar patterns may exist in the general population. This model may complement previously proposed inversion-based mechanisms within a longitudinal kinetic chain framework.
Although speculative, this hypothesis proposes a plausible biomechanical framework linking proximal pelvic dysfunction with distal ankle injury mechanisms. Further clinical and biomechanical investigation is warranted.
This model is hypothesis-based and has not yet been validated experimentally. Variability in anatomy and movement patterns must be considered.
The proposed model should be regarded as a biomechanical hypothesis derived from clinical observations and theoretical analysis. Future investigations should evaluate the reproducibility, predictive value, and external validity of this framework through prospective clinical studies, biomechanical modeling, motion analysis, and multicenter collaborations. Comparative studies involving asymptomatic individuals, athletes with eversion ankle sprains, and independent research groups will be necessary to determine the applicability and generalizability of the proposed mechanism.
Further research should investigate:
· pelvic asymmetry and medial loading
· arch collapse and stability
· tibiofibular mechanics
· effectiveness of targeted interventions
Anterior innominate rotation may contribute to eversion ankle sprain risk through a proximal-to-distal biomechanical pathway. Recognizing this pattern may provide a framework for future biomechanical investigation and potential injury prevention strategies.
· AS may contribute to eversion ankle sprain risk
· Pelvic asymmetry may influence medial loading
· Toe-in and arch collapse may predispose to eversion
· Screening may improve prevention
During the preparation of this work the author used Chat GPT in order to generate better content organization and improve language and readability since his first language is Spanish, after using this tool, the author reviewed and edited the content as needed and takes full responsibility for the content of the published article.