The Association between Foot Morphology and Dynamic Balance Performance as Measured by the Star Excursion Balance Test

Abstract

Open Access Research Article neuromuscular control [4]. The protocol is easily implemented in the field and clinic, requiring no specialized equipment or advanced training. In addition, the SEBT is challenging enough to stress the postural control system, making it an ideal task to be used by athletic trainers and physical therapists to assess balance within athletic populations [3,5]. The association between dynamic balance, as measured by the SEBT, and foot morphology was investigated in 2 studies with mixed results [2,6]. On one hand, Gribble and Hertel [6] found no significant relationships between foot types and reach distances on the SEBT using rearfoot and forefoot angles (classified as pes planus, pes rectus, and pes cavus) in 30 recreationally active participants. They concluded that foot type was not an important covariate of balance performance. On the other hand, Cote et al. [2] found differences in reach distance on a few SEBT directions as a function of foot type in 16 healthy individuals when foot type was determined using the navicular drop method (classified as pronated, neutral or supinated). They suggest that postural stability is affected by foot morphology and that foot type needs to be controlled for when measuring balance performance [2]. These differing results suggest that the association between dynamic balance performance and foot morphology is not well understood. In addition to morphology, another factor that may be important in order to interpret dynamic balance performance is history of injuries. While ankle sprains [4] and ACL deficiencies [7] were found to impact performance on the SEBT among recreationally active participants, the effect of previous injury, in general, has not been investigated. Given that almost every epidemiological study of running has identified previous injury (usually defined as an injury occurring in the 12 months prior to the study) as a risk factor for future injuries [8,9], previous injury seems to be an important characteristic of recreationally active persons, especially runners. The mechanism that links past and future injuries, however, still needs clarification [10]. Impaired dynamic balance performance is one potential underlying Abstract The purposes of this descriptive study were to explore the association between foot morphology, severity of past injuries and Star Excursion Balance Test (SEBT) performance in recreational runners. We interviewed 20 healthy recreational runners (aged 23-58 years) about their running habits and history of injuries. We calculated arch height index, a measure of foot morphology, from their static footprint. Participants performed the SEBT. Participants with lower medial longitudinal foot arch reached significantly farther on all SEBT directions except for anterolateral. The Spearman correlation (Rs) between arch index and those 7 directions ranged from 0.455 to 0.617 (p values ranging from 0.01 to 0.05). Severity of injuries in the past was not associated with SEBT performance. Assessing parameters that are associated with balance performance can help therapists to understand the underlying impairments leading to decreased or enhanced dynamic balance performance. Researchers and clinicians need to be aware of potential differences in dynamic balance performance in individuals with different foot morphologies.