The kinetic chain relationship of pes planus and segmental dysfunction at L3 level

Helen Terentjev                                                                                Supervisor: Fiona Hamilton

Abstract

Aims of study: This study was set to examine the lower extremity, pelvis and lumbar spine alignment in healthy and physically active volunteers with functional flat foot (pes planus), in order to identify whether a statistically significant kinetic chain relationship was present between the degree of pes planus and the position of the third lumbar vertebra (L3). 

Methods: 20 healthy and physically active subjects were randomly selected for the study: 9 females and 11 males, mean age = 32.1 years (standard deviation 12.9), mean height = 170.7 cm (standard deviation 8.4), mean weight = 74.8 kg (standard deviation 9.9). Subjects were assessed for navicular drop, pelvic tilt and motion restriction in the lumbar spine.  Statistical analysis was performed to identify correlations in these measures. 

Findings: 7 subjects had pronated feet (ND between 9 and 14 mm), with mean ND=10.4 mm (standard deviation 0.3); 13 subjects had neutral feet (ND between 4 and 9 mm), with mean ND=6.7 mm (standard deviation 1.3). A significant statistical correlation between the degrees of pes planus and pelvic tilt indicates that this kinetic chain connection is strong and unambiguous. However, the results do not provide sufficiently strong evidence either for the presence, or the absence, of correlation between pes planus and L3 segmental dysfunction. A high incidence (90%) of L3 restriction was found amongst apparently healthy and physically active individuals.