No abstract

These observations support the concept that Achilles tendinopathy is a bilateral or systemic process and structural changes associated with symptomatic tendinopathy alter fluid movement within the tendon matrix. Altered fluid movement may disrupt remodeling and homeostatic processes and represents a plausible mechanism underlying the progression of tendinopathy.

III.

Previous research employing indirect measures of arch structure, such as those derived from footprints, have indicated that obesity results in a ''flatter'' foot type. In the absence of radiographic measures, however, definitive conclusions regarding the osseous alignment of the foot cannot be made. We determined the effect of body mass index (BMI) on radiographic and footprint-based measures of arch structure. The research was a cross-sectional study in which radiographic and footprint-based measures of foot structure were made in 30 subjects (10 males, 20 female) in addition to standard anthropometric measures of height, weight, and BMI. Multiple (univariate) Previous research employing footprint-based measures of arch structure, such as the Arch Index (AI), have typically reported a ''flatter'' foot in obese adults and children. 1-6 ''Flat feet'' have been suggested to increase stress within soft tissue structures of the lower limb and thereby increase the propensity for injury. 7 While clinical data have confirmed a greater prevalence of musculoskeletal pain in obese individuals, primarily involving the lower limb, 8,9 body adiposity has also been shown to influence the amount of soft tissue beneath the foot. 10-12 Moreover, positive linear associations have been found between estimates of total body fat, derived from bioelectrical impedance, and the midfoot contact area of footprints. 13 As such, obesity has been hypothesized to act as a potentially confounding factor in footprint-based estimates of arch structure.In support of this concept, Gilmour and Burns 14 found that while footprint-based estimates of arch height differed between obese and normal weight children, caliper measures of navicular height did not. Thus, it would appear that obesity may selectively distort the contact area of the foot, without affecting the osseous structure of the medial longitudinal arch. However, the validity of skin-based caliper measures of arch structure, particularly in obese populations, is questionable, 15 and in the absence of radiographic measures, definitive conclusions regarding the effect of obesity on the osseous alignment of the foot cannot be made.The aim of the current investigation, therefore, was to evaluate the effect of body mass index (BMI) on both radiographic and footprint-based measures of adult arch structure. We hypothesized that footprintbased measures of arch height would be linearly associated with adiposity, as defined by the BMI, while radiographic measures of foot structure would not. MATERIALS AND METHODS ParticipantsA convenience sample of 30 healthy volunteers (10 male and 20 female) were recruited from the greater Brisbane metropolitan area. Participants possessed a mean (SD) age of 47.9 (11.6) years, height of 1.68 (0.10) m and body weight of 80.8 (10.2) kg. The average BMI for the group was 28.8 (2.9) kg m À2 with values ranging from 23.9 kg m À2 (normal weight) to 35.2 kg m À2 (obese class II). 16 Study participants with a history of lower limb pain within 3 months of the ...

This study is the first to show that quadriceps exercise invokes structural alignment and fluid movement within the matrix that are manifested by changes in echotexture and transverse strain in the patellar tendon.