Distal effects of Femoroacetabular Impingement (FAI)
Until recently, femoroacetabular impingement (FAI) has been a poorly characterized and managed musculoskeletal condition of the hip. The authors of the current study set out to determine the effects, if any, that confirmed FAI will have on the biomechanics of the distal articulations of the lower extremity. It was shown that young adult men with cam-type FAI presented with excessively inverted hindfoot at heel strike with a reduction in the overall maximum eversion during stance phase.
Kinematics were examined on 15 adult men with cam-type femoroacetabular impingement utilizing three dimensional gait analysis. Each participant was instructed to perform three walking gait cycles while measurements were ascertained.
Previous studies have focussed on the effect FAI has on the proximal articulations of the hip joint. For this reason, the authors set out to determine the role FAI has on distal articulations such is in the foot.
It was shown that overall patients with FAI exhibited decreased pelvic internal rotation and abduction at heel strike compared to controls. This in turn translated to an increase in hindfoot inversion at heel strike. During stance phase, individuals with FAI demonstrated an increase in sagittal pelvic ROM as well as reduced maximum eversion during the stance phase.
This study confirms the notion that a structural variation at the hip can have downstream effects in our biomechanics, ultimately affecting the way we should approach treatment and further injury prevention.
Taken together, knowing that patients with FAI have quantifiable changes in there distal articulations, should orthotics and insoles be considered in a population that has a non-modifiable structural difference in their hip?
> From: Hetsroni et al., Clin Biomech (2015) 5(Epub ahead of print). All rights reserved to elsevier ltd.. Click here for the Pubmed summary.