Hip And Abdominal Subcutaneous Adipose Tissue Thickness In Patients With Patellofemoral Pain

Hip and core muscle dysfunction have been linked to patellofemoral pain (PFP). While increased abdominal adiposity has been linked to other chronic musculoskeletal conditions; the influence of hip or abdominal adiposity in PFP has been understudied. Body composition has previously been reported in those with PFP; however specially examining adiposity of the hip and abdomen has not been evaluated. PURPOSE: To determine differences and relationships between hip and abdominal subcutaneous adipose tissue thickness in seated and standing positions in individuals with PFP. METHODS: Twenty-six individuals (Height: 169.23 ± 11.29 cm, Weight:78.27 ± 20.89 kg, Body Mass Index (BMI): 27.09 ± 5.72, 11 M, 15F) who self-reported PFP for at least 3 months participated in this study. Three ultrasound images were taken on the side of pain in a supine, hook-lying on a table for the abdomen, and side-lying on the contralateral hip. Three additional images while the participant was standing were captured with the transducer secured to the lateral abdominal wall and the posterolateral hip with an elastic belt and foam block. Subcutaneous tissue thickness (adiposity) was measured in centimeters (cm) on each image and averaged. Paired t-tests were used to compare hip and abdominal adipose thickness while on the table and while standing. Pearson’s (r) correlation coefficients determined the relationships between subcutaneous adipose thickness, height, weight, BMI, current and worst pain level in the past week. Pain was measured with a visual analog scale (0-100). Alpha was set to 0.05 a-priori. RESULTS: Hip adipose tissue (Table:1.45 ± 0.55 cm; Standing: 1.50 ± 0.61 cm) was thicker than abdominal adipose (Table: 0.93 ± 0.49 cm; Standing: 0.85 ± 0.46 cm) in tabletop (p < .001) and standing (p < .001). Current pain was 26.50 ± 25.06 and worst pain was 58.19 ± 21.11. Hip adiposity on the table had a moderate positive relationship with current pain (r = 0.46, p = .018). Weight and BMI were related to abdominal and hip adipose thickness measures, in both table and standing positions (r = 0.51-0.78, p < .05). CONCLUSIONS: Adiposity of the hip and abdomen should be considered when evaluating and treating PFP. Special attention may be paid to the hip region as more adiposity was related to higher pain levels. Supported by: This work was supported by a grant from the Department of Defense.